diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 01d5876635b0..6e29feef7b00 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -71,6 +71,22 @@ jobs:
           tox_extra_args: "-n 4"
           test_mypyc: true
 
+        - name: Test suit with py313-dev-ubuntu, mypyc-compiled
+          python: '3.13-dev'
+          arch: x64
+          os: ubuntu-latest
+          toxenv: py
+          tox_extra_args: "-n 4"
+          test_mypyc: true
+        # - name: Test suit with py314-dev-ubuntu
+        #   python: '3.14-dev'
+        #   arch: x64
+        #   os: ubuntu-latest
+        #   toxenv: py
+        #   tox_extra_args: "-n 4"
+        #   allow_failure: true
+        #   test_mypyc: true
+
         - name: mypyc runtime tests with py39-macos
           python: '3.9.18'
           arch: x64
@@ -119,12 +135,10 @@ jobs:
       MYPY_FORCE_TERMINAL_WIDTH: 200
       # Pytest
       PYTEST_ADDOPTS: --color=yes
+
     steps:
     - uses: actions/checkout@v4
-    - uses: actions/setup-python@v5
-      with:
-        python-version: ${{ matrix.python }}
-        architecture: ${{ matrix.arch }}
+
     - name: Debug build
       if: ${{ matrix.debug_build }}
       run: |
@@ -132,38 +146,58 @@ jobs:
         PYTHONDIR=~/python-debug/python-$PYTHONVERSION
         VENV=$PYTHONDIR/env
         ./misc/build-debug-python.sh $PYTHONVERSION $PYTHONDIR $VENV
+        # TODO: does this do anything? env vars aren't passed to the next step right
         source $VENV/bin/activate
+    - name: Latest Dev build
+      if: ${{ endsWith(matrix.python, '-dev') }}
+      run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends \
+            build-essential gdb lcov libbz2-dev libffi-dev libgdbm-dev liblzma-dev libncurses5-dev \
+            libreadline6-dev libsqlite3-dev libssl-dev lzma lzma-dev tk-dev uuid-dev zlib1g-dev
+          git clone --depth 1 https://github.com/python/cpython.git /tmp/cpython --branch $( echo ${{ matrix.python }} | sed 's/-dev//' )
+          cd /tmp/cpython
+          echo git rev-parse HEAD; git rev-parse HEAD
+          git show --no-patch
+          ./configure --prefix=/opt/pythondev
+          make -j$(nproc)
+          sudo make install
+          sudo ln -s /opt/pythondev/bin/python3 /opt/pythondev/bin/python
+          sudo ln -s /opt/pythondev/bin/pip3 /opt/pythondev/bin/pip
+          echo "/opt/pythondev/bin" >> $GITHUB_PATH
+    - uses: actions/setup-python@v5
+      if: ${{ !(matrix.debug_build || endsWith(matrix.python, '-dev')) }}
+      with:
+        python-version: ${{ matrix.python }}
+        architecture: ${{ matrix.arch }}
+
     - name: Install tox
-      run: pip install setuptools==68.2.2 tox==4.11.0
+      run: |
+        echo PATH; echo $PATH
+        echo which python; which python
+        echo which pip; which pip
+        echo python version; python -c 'import sys; print(sys.version)'
+        echo debug build; python -c 'import sysconfig; print(bool(sysconfig.get_config_var("Py_DEBUG")))'
+        echo os.cpu_count; python -c 'import os; print(os.cpu_count())'
+        echo os.sched_getaffinity; python -c 'import os; print(len(getattr(os, "sched_getaffinity", lambda *args: [])(0)))'
+        pip install setuptools==68.2.2 tox==4.11.0
+
     - name: Compiled with mypyc
       if: ${{ matrix.test_mypyc }}
       run: |
         pip install -r test-requirements.txt
         CC=clang MYPYC_OPT_LEVEL=0 MYPY_USE_MYPYC=1 pip install -e .
+
     - name: Setup tox environment
       run: |
-        tox run -e ${{ matrix.toxenv }} --notest
-        python -c 'import os; print("os.cpu_count", os.cpu_count(), "os.sched_getaffinity", len(getattr(os, "sched_getaffinity", lambda *args: [])(0)))'
+        tox run -e ${{ matrix.toxenv }} --notes
     - name: Test
       run: tox run -e ${{ matrix.toxenv }} --skip-pkg-install -- ${{ matrix.tox_extra_args }}
+      continue-on-error: ${{ matrix.allow_failure == 'true' }}
 
-  python-nightly:
-    runs-on: ubuntu-latest
-    name: Test suite with Python nightly
-    steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-python@v4
-        with:
-          python-version: '3.13-dev'
-      - name: Install tox
-        run: pip install setuptools==68.2.2 tox==4.11.0
-      - name: Setup tox environment
-        run: tox run -e py --notest
-      - name: Test
-        run: tox run -e py --skip-pkg-install -- "-n 4"
-        continue-on-error: true
-      - name: Mark as a success
-        run: exit 0
+    - name: Mark as success (check failures manually)
+      if: ${{ matrix.allow_failure == 'true' }}
+      run: exit 0
 
   python_32bits:
     runs-on: ubuntu-latest
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b544e05ee573..9632cb39a8b1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,7 +11,7 @@ We’ve just uploaded mypy 1.11 to the Python Package Index ([PyPI](https://pypi
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### Support Python 3.12 Syntax for Generics (PEP 695)
+### Support Python 3.12 Syntax for Generics (PEP 695)
 
 Mypy now supports the new type parameter syntax introduced in Python 3.12 ([PEP 695](https://peps.python.org/pep-0695/)).
 This feature is still experimental and must be enabled with the `--enable-incomplete-feature=NewGenericSyntax` flag, or with `enable_incomplete_feature = NewGenericSyntax` in the mypy configuration file.
@@ -40,7 +40,7 @@ type A[T] = C[list[T]]
 This feature was contributed by Jukka Lehtosalo.
 
 
-#### Support for `functools.partial`
+### Support for `functools.partial`
 
 Mypy now type checks uses of `functools.partial`. Previously mypy would accept arbitrary arguments.
 
@@ -60,7 +60,7 @@ g(11)
 This feature was contributed by Shantanu (PR [16939](https://github.com/python/mypy/pull/16939)).
 
 
-#### Stricter Checks for Untyped Overrides
+### Stricter Checks for Untyped Overrides
 
 Past mypy versions didn't check if untyped methods were compatible with overridden methods. This would result in false negatives. Now mypy performs these checks when using `--check-untyped-defs`.
 
@@ -78,7 +78,7 @@ class Derived(Base):
 This feature was contributed by Steven Troxler (PR [17276](https://github.com/python/mypy/pull/17276)).
 
 
-#### Type Inference Improvements
+### Type Inference Improvements
 
 The new polymorphic inference algorithm introduced in mypy 1.5 is now used in more situations. This improves type inference involving generic higher-order functions, in particular.
 
@@ -95,14 +95,14 @@ for x in (1, 'x'):
 This was also contributed by Ivan Levkivskyi (PR [17408](https://github.com/python/mypy/pull/17408)).
 
 
-#### Improvements to Detection of Overlapping Overloads
+### Improvements to Detection of Overlapping Overloads
 
 The details of how mypy checks if two `@overload` signatures are unsafely overlapping were overhauled. This both fixes some false positives, and allows mypy to detect additional unsafe signatures.
 
 This feature was contributed by Ivan Levkivskyi (PR [17392](https://github.com/python/mypy/pull/17392)).
 
 
-#### Better Support for Type Hints in Expressions
+### Better Support for Type Hints in Expressions
 
 Mypy now allows more expressions that evaluate to valid type annotations in all expression contexts. The inferred types of these expressions are also sometimes more precise. Previously they were often `object`.
 
@@ -117,7 +117,7 @@ print(Callable[[], int] | None)  # No error
 This feature was contributed by Jukka Lehtosalo (PR [17404](https://github.com/python/mypy/pull/17404)).
 
 
-#### Mypyc Improvements
+### Mypyc Improvements
 
 Mypyc now supports the new syntax for generics introduced in Python 3.12 (see above). Another notable improvement is signficantly faster basic operations on `int` values.
 
@@ -129,18 +129,18 @@ Mypyc now supports the new syntax for generics introduced in Python 3.12 (see ab
  * Allow specifying primitives as pure (Jukka Lehtosalo, PR [17263](https://github.com/python/mypy/pull/17263))
 
 
-#### Changes to Stubtest
+### Changes to Stubtest
  * Ignore `_ios_support` (Alex Waygood, PR [17270](https://github.com/python/mypy/pull/17270))
  * Improve support for Python 3.13 (Shantanu, PR [17261](https://github.com/python/mypy/pull/17261))
 
 
-#### Changes to Stubgen
+### Changes to Stubgen
  * Gracefully handle invalid `Optional` and recognize aliases to PEP 604 unions (Ali Hamdan, PR [17386](https://github.com/python/mypy/pull/17386))
  * Fix for Python 3.13 (Jelle Zijlstra, PR [17290](https://github.com/python/mypy/pull/17290))
  * Preserve enum value initialisers (Shantanu, PR [17125](https://github.com/python/mypy/pull/17125))
 
 
-#### Miscellaneous New Features
+### Miscellaneous New Features
  * Add error format support and JSON output option via `--output json` (Tushar Sadhwani, PR [11396](https://github.com/python/mypy/pull/11396))
  * Support `enum.member` in Python 3.11+ (Nikita Sobolev, PR [17382](https://github.com/python/mypy/pull/17382))
  * Support `enum.nonmember` in Python 3.11+ (Nikita Sobolev, PR [17376](https://github.com/python/mypy/pull/17376))
@@ -149,7 +149,7 @@ Mypyc now supports the new syntax for generics introduced in Python 3.12 (see ab
  * Add support for `__spec__` (Shantanu, PR [14739](https://github.com/python/mypy/pull/14739))
 
 
-#### Changes to Error Reporting
+### Changes to Error Reporting
  * Mention `--enable-incomplete-feature=NewGenericSyntax` in messages (Shantanu, PR [17462](https://github.com/python/mypy/pull/17462))
  * Do not report plugin-generated methods with `explicit-override` (sobolevn, PR [17433](https://github.com/python/mypy/pull/17433))
  * Use and display namespaces for function type variables (Ivan Levkivskyi, PR [17311](https://github.com/python/mypy/pull/17311))
@@ -162,7 +162,7 @@ Mypyc now supports the new syntax for generics introduced in Python 3.12 (see ab
  * Fix error reporting on cached run after uninstallation of third party library (Shantanu, PR [17420](https://github.com/python/mypy/pull/17420))
 
 
-#### Fixes for Crashes
+### Fixes for Crashes
  * Fix daemon crash on invalid type in TypedDict (Ivan Levkivskyi, PR [17495](https://github.com/python/mypy/pull/17495))
  * Fix crash and bugs related to `partial()` (Ivan Levkivskyi, PR [17423](https://github.com/python/mypy/pull/17423))
  * Fix crash when overriding with unpacked TypedDict (Ivan Levkivskyi, PR [17359](https://github.com/python/mypy/pull/17359))
@@ -174,14 +174,14 @@ Mypyc now supports the new syntax for generics introduced in Python 3.12 (see ab
  * Fix crash on type comment inside generic definitions (Bénédikt Tran, PR [16849](https://github.com/python/mypy/pull/16849))
 
 
-#### Changes to Documentation
+### Changes to Documentation
  * Use inline config in documentation for optional error codes (Shantanu, PR [17374](https://github.com/python/mypy/pull/17374))
  * Use lower-case generics in documentation (Seo Sanghyeon, PR [17176](https://github.com/python/mypy/pull/17176))
  * Add documentation for show-error-code-links (GiorgosPapoutsakis, PR [17144](https://github.com/python/mypy/pull/17144))
  * Update CONTRIBUTING.md to include commands for Windows (GiorgosPapoutsakis, PR [17142](https://github.com/python/mypy/pull/17142))
 
 
-#### Other Notable Improvements and Fixes
+### Other Notable Improvements and Fixes
  * Fix ParamSpec inference against TypeVarTuple (Ivan Levkivskyi, PR [17431](https://github.com/python/mypy/pull/17431))
  * Fix explicit type for `partial` (Ivan Levkivskyi, PR [17424](https://github.com/python/mypy/pull/17424))
  * Always allow lambda calls (Ivan Levkivskyi, PR [17430](https://github.com/python/mypy/pull/17430))
@@ -206,12 +206,12 @@ Mypyc now supports the new syntax for generics introduced in Python 3.12 (see ab
  * Fix Literal strings containing pipe characters (Jelle Zijlstra, PR [17148](https://github.com/python/mypy/pull/17148))
 
 
-#### Typeshed Updates
+### Typeshed Updates
 
 Please see [git log](https://github.com/python/typeshed/commits/main?after=6dda799d8ad1d89e0f8aad7ac41d2d34bd838ace+0&branch=main&path=stdlib) for full list of standard library typeshed stub changes.
 
 
-#### Acknowledgements
+### Acknowledgements
 Thanks to all mypy contributors who contributed to this release:
 
 - Alex Waygood
@@ -254,7 +254,7 @@ We’ve just uploaded mypy 1.10 to the Python Package Index ([PyPI](https://pypi
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### Support TypeIs (PEP 742)
+### Support TypeIs (PEP 742)
 
 Mypy now supports `TypeIs` ([PEP 742](https://peps.python.org/pep-0742/)), which allows
 functions to narrow the type of a value, similar to `isinstance()`. Unlike `TypeGuard`,
@@ -281,7 +281,7 @@ can be used on earlier Python versions by importing it from
 
 This feature was contributed by Jelle Zijlstra (PR [16898](https://github.com/python/mypy/pull/16898)).
 
-#### Support TypeVar Defaults (PEP 696)
+### Support TypeVar Defaults (PEP 696)
 
 [PEP 696](https://peps.python.org/pep-0696/) adds support for type parameter defaults.
 Example:
@@ -308,7 +308,7 @@ can be used with earlier Python releases by importing `TypeVar` from
 This feature was contributed by Marc Mueller (PR [16878](https://github.com/python/mypy/pull/16878)
 and PR [16925](https://github.com/python/mypy/pull/16925)).
 
-#### Support TypeAliasType (PEP 695)
+### Support TypeAliasType (PEP 695)
 As part of the initial steps towards implementing [PEP 695](https://peps.python.org/pep-0695/), mypy now supports `TypeAliasType`.
 `TypeAliasType` provides a backport of the new `type` statement in Python 3.12.
 
@@ -344,7 +344,7 @@ c: ListOrSet[str] = 'test'  # error: Incompatible types in assignment (expressio
 
 This feature was contributed by Ali Hamdan (PR [16926](https://github.com/python/mypy/pull/16926), PR [17038](https://github.com/python/mypy/pull/17038) and PR [17053](https://github.com/python/mypy/pull/17053))
 
-#### Detect Additional Unsafe Uses of super()
+### Detect Additional Unsafe Uses of super()
 
 Mypy will reject unsafe uses of `super()` more consistently, when the target has a
 trivial (empty) body. Example:
@@ -360,13 +360,13 @@ class Sub(Proto):
 
 This feature was contributed by Shantanu (PR [16756](https://github.com/python/mypy/pull/16756)).
 
-#### Stubgen Improvements
+### Stubgen Improvements
 - Preserve empty tuple annotation (Ali Hamdan, PR [16907](https://github.com/python/mypy/pull/16907))
 - Add support for PEP 570 positional-only parameters (Ali Hamdan, PR [16904](https://github.com/python/mypy/pull/16904))
 - Replace obsolete typing aliases with builtin containers (Ali Hamdan, PR [16780](https://github.com/python/mypy/pull/16780))
 - Fix generated dataclass `__init__` signature (Ali Hamdan, PR [16906](https://github.com/python/mypy/pull/16906))
 
-#### Mypyc Improvements
+### Mypyc Improvements
 
 - Provide an easier way to define IR-to-IR transforms (Jukka Lehtosalo, PR [16998](https://github.com/python/mypy/pull/16998))
 - Implement lowering pass and add primitives for int (in)equality (Jukka Lehtosalo, PR [17027](https://github.com/python/mypy/pull/17027))
@@ -377,15 +377,15 @@ This feature was contributed by Shantanu (PR [16756](https://github.com/python/m
 - Fix compilation of unreachable comprehensions (Richard Si, PR [15721](https://github.com/python/mypy/pull/15721))
 - Don't crash on non-inlinable final local reads (Richard Si, PR [15719](https://github.com/python/mypy/pull/15719))
 
-#### Documentation Improvements
+### Documentation Improvements
 - Import `TypedDict` from `typing` instead of `typing_extensions` (Riccardo Di Maio, PR [16958](https://github.com/python/mypy/pull/16958))
 - Add missing `mutable-override` to section title (James Braza, PR [16886](https://github.com/python/mypy/pull/16886))
 
-#### Error Reporting Improvements
+### Error Reporting Improvements
 
 - Use lower-case generics more consistently in error messages (Jukka Lehtosalo, PR [17035](https://github.com/python/mypy/pull/17035))
 
-#### Other Notable Changes and Fixes
+### Other Notable Changes and Fixes
 - Fix incorrect inferred type when accessing descriptor on union type (Matthieu Devlin, PR [16604](https://github.com/python/mypy/pull/16604))
 - Fix crash when expanding invalid `Unpack` in a `Callable` alias (Ali Hamdan, PR [17028](https://github.com/python/mypy/pull/17028))
 - Fix false positive when string formatting with string enum (roberfi, PR [16555](https://github.com/python/mypy/pull/16555))
@@ -403,15 +403,15 @@ This feature was contributed by Shantanu (PR [16756](https://github.com/python/m
 - Experimental: Support TypedDict within `type[...]` (Marc Mueller, PR [16963](https://github.com/python/mypy/pull/16963))
 - Experimtental: Fix issue with TypedDict with optional keys in `type[...]` (Marc Mueller, PR [17068](https://github.com/python/mypy/pull/17068))
 
-#### Typeshed Updates
+### Typeshed Updates
 
 Please see [git log](https://github.com/python/typeshed/commits/main?after=6dda799d8ad1d89e0f8aad7ac41d2d34bd838ace+0&branch=main&path=stdlib) for full list of standard library typeshed stub changes.
 
-#### Mypy 1.10.1
+### Mypy 1.10.1
 
 - Fix error reporting on cached run after uninstallation of third party library (Shantanu, PR [17420](https://github.com/python/mypy/pull/17420))
 
-#### Acknowledgements
+### Acknowledgements
 Thanks to all mypy contributors who contributed to this release:
 
 - Alex Waygood
@@ -454,7 +454,7 @@ We’ve just uploaded mypy 1.9 to the Python Package Index ([PyPI](https://pypi.
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### Breaking Changes
+### Breaking Changes
 
 Because the version of typeshed we use in mypy 1.9 doesn't support 3.7, neither does mypy 1.9. (Jared Hance, PR [16883](https://github.com/python/mypy/pull/16883))
 
@@ -476,7 +476,7 @@ projects to use `--local-partial-types`, but it's not yet clear whether
 this is practical. The migration usually involves adding some
 explicit type annotations to module-level and class-level variables.
 
-#### Basic Support for Type Parameter Defaults (PEP 696)
+### Basic Support for Type Parameter Defaults (PEP 696)
 
 This release contains new experimental support for type parameter
 defaults ([PEP 696](https://peps.python.org/pep-0696)). Please try it
@@ -506,7 +506,7 @@ reveal_type(Context().bot)
 reveal_type(Context[MyBot]().bot)
 ```
 
-#### Type-checking Improvements
+### Type-checking Improvements
  * Fix missing type store for overloads (Marc Mueller, PR [16803](https://github.com/python/mypy/pull/16803))
  * Fix `'WriteToConn' object has no attribute 'flush'` (Charlie Denton, PR [16801](https://github.com/python/mypy/pull/16801))
  * Improve TypeAlias error messages (Marc Mueller, PR [16831](https://github.com/python/mypy/pull/16831))
@@ -519,11 +519,11 @@ reveal_type(Context[MyBot]().bot)
  * Add `alias` support to `field()` in `attrs` plugin (Nikita Sobolev, PR [16610](https://github.com/python/mypy/pull/16610))
  * Improve attrs hashability detection (Tin Tvrtković, PR [16556](https://github.com/python/mypy/pull/16556))
 
-#### Performance Improvements
+### Performance Improvements
 
  * Speed up finding function type variables (Jukka Lehtosalo, PR [16562](https://github.com/python/mypy/pull/16562))
 
-#### Documentation Updates
+### Documentation Updates
 
  * Document supported values for `--enable-incomplete-feature` in "mypy --help" (Froger David, PR [16661](https://github.com/python/mypy/pull/16661))
  * Update new type system discussion links (thomaswhaley, PR [16841](https://github.com/python/mypy/pull/16841))
@@ -533,7 +533,7 @@ reveal_type(Context[MyBot]().bot)
  * Fix numbering error (Stefanie Molin, PR [16838](https://github.com/python/mypy/pull/16838))
  * Various documentation improvements (Shantanu, PR [16836](https://github.com/python/mypy/pull/16836))
 
-#### Stubtest Improvements
+### Stubtest Improvements
  * Ignore private function/method parameters when they are missing from the stub (private parameter names start with a single underscore and have a default) (PR [16507](https://github.com/python/mypy/pull/16507))
  * Ignore a new protocol dunder (Alex Waygood, PR [16895](https://github.com/python/mypy/pull/16895))
  * Private parameters can be omitted (Sebastian Rittau, PR [16507](https://github.com/python/mypy/pull/16507))
@@ -541,13 +541,13 @@ reveal_type(Context[MyBot]().bot)
  * Adjust symbol table logic (Shantanu, PR [16823](https://github.com/python/mypy/pull/16823))
  * Fix posisitional-only handling in overload resolution (Shantanu, PR [16750](https://github.com/python/mypy/pull/16750))
 
-#### Stubgen Improvements
+### Stubgen Improvements
  * Fix crash on star unpack of TypeVarTuple (Ali Hamdan, PR [16869](https://github.com/python/mypy/pull/16869))
  * Use PEP 604 unions everywhere (Ali Hamdan, PR [16519](https://github.com/python/mypy/pull/16519))
  * Do not ignore property deleter (Ali Hamdan, PR [16781](https://github.com/python/mypy/pull/16781))
  * Support type stub generation for `staticmethod` (WeilerMarcel, PR [14934](https://github.com/python/mypy/pull/14934))
 
-#### Acknowledgements
+### Acknowledgements
 
 ​Thanks to all mypy contributors who contributed to this release:
 
@@ -591,7 +591,7 @@ We’ve just uploaded mypy 1.8 to the Python Package Index ([PyPI](https://pypi.
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### Type-checking Improvements
+### Type-checking Improvements
  * Do not intersect types in isinstance checks if at least one is final (Christoph Tyralla, PR [16330](https://github.com/python/mypy/pull/16330))
  * Detect that `@final` class without `__bool__` cannot have falsey instances (Ilya Priven, PR [16566](https://github.com/python/mypy/pull/16566))
  * Do not allow `TypedDict` classes with extra keywords (Nikita Sobolev, PR [16438](https://github.com/python/mypy/pull/16438))
@@ -601,44 +601,44 @@ You can read the full documentation for this release on [Read the Docs](http://m
  * Allow type ignores of PEP 695 constructs (Shantanu, PR [16608](https://github.com/python/mypy/pull/16608))
  * Enable `type_check_only` support for `TypedDict` and `NamedTuple` (Nikita Sobolev, PR [16469](https://github.com/python/mypy/pull/16469))
 
-#### Performance Improvements
+### Performance Improvements
  * Add fast path to analyzing special form assignments (Jukka Lehtosalo, PR [16561](https://github.com/python/mypy/pull/16561))
 
-#### Improvements to Error Reporting
+### Improvements to Error Reporting
  * Don't show documentation links for plugin error codes (Ivan Levkivskyi, PR [16383](https://github.com/python/mypy/pull/16383))
  * Improve error messages for `super` checks and add more tests (Nikita Sobolev, PR [16393](https://github.com/python/mypy/pull/16393))
  * Add error code for mutable covariant override (Ivan Levkivskyi, PR [16399](https://github.com/python/mypy/pull/16399))
 
-#### Stubgen Improvements
+### Stubgen Improvements
  * Preserve simple defaults in function signatures (Ali Hamdan, PR [15355](https://github.com/python/mypy/pull/15355))
  * Include `__all__` in output (Jelle Zijlstra, PR [16356](https://github.com/python/mypy/pull/16356))
  * Fix stubgen regressions with pybind11 and mypy 1.7 (Chad Dombrova, PR [16504](https://github.com/python/mypy/pull/16504))
 
-#### Stubtest Improvements
+### Stubtest Improvements
  * Improve handling of unrepresentable defaults (Jelle Zijlstra, PR [16433](https://github.com/python/mypy/pull/16433))
  * Print more helpful errors if a function is missing from stub (Alex Waygood, PR [16517](https://github.com/python/mypy/pull/16517))
  * Support `@type_check_only` decorator (Nikita Sobolev, PR [16422](https://github.com/python/mypy/pull/16422))
  * Warn about missing `__del__` (Shantanu, PR [16456](https://github.com/python/mypy/pull/16456))
  * Fix crashes with some uses of `final` and `deprecated` (Shantanu, PR [16457](https://github.com/python/mypy/pull/16457))
 
-#### Fixes to Crashes
+### Fixes to Crashes
  * Fix crash with type alias to `Callable[[Unpack[Tuple[Any, ...]]], Any]` (Alex Waygood, PR [16541](https://github.com/python/mypy/pull/16541))
  * Fix crash on TypeGuard in `__call__` (Ivan Levkivskyi, PR [16516](https://github.com/python/mypy/pull/16516))
  * Fix crash on invalid enum in method (Ivan Levkivskyi, PR [16511](https://github.com/python/mypy/pull/16511))
  * Fix crash on unimported Any in TypedDict (Ivan Levkivskyi, PR [16510](https://github.com/python/mypy/pull/16510))
 
-#### Documentation Updates
+### Documentation Updates
  * Update soft-error-limit default value to -1 (Sveinung Gundersen, PR [16542](https://github.com/python/mypy/pull/16542))
  * Support Sphinx 7.x (Michael R. Crusoe, PR [16460](https://github.com/python/mypy/pull/16460))
 
-#### Other Notable Changes and Fixes
+### Other Notable Changes and Fixes
  * Allow mypy to output a junit file with per-file results (Matthew Wright, PR [16388](https://github.com/python/mypy/pull/16388))
 
-#### Typeshed Updates
+### Typeshed Updates
 
 Please see [git log](https://github.com/python/typeshed/commits/main?after=4a854366e03dee700109f8e758a08b2457ea2f51+0&branch=main&path=stdlib) for full list of standard library typeshed stub changes.
 
-#### Acknowledgements
+### Acknowledgements
 
 ​Thanks to all mypy contributors who contributed to this release:
 
@@ -672,7 +672,7 @@ We’ve just uploaded mypy 1.7 to the Python Package Index ([PyPI](https://pypi.
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### Using TypedDict for `**kwargs` Typing
+### Using TypedDict for `**kwargs` Typing
 
 Mypy now has support for using `Unpack[...]` with a TypedDict type to annotate `**kwargs` arguments enabled by default. Example:
 
@@ -702,7 +702,7 @@ Refer to [PEP 692](https://peps.python.org/pep-0692/) for more information. Note
 
 This was contributed by Ivan Levkivskyi back in 2022 (PR [13471](https://github.com/python/mypy/pull/13471)).
 
-#### TypeVarTuple Support Enabled (Experimental)
+### TypeVarTuple Support Enabled (Experimental)
 
 Mypy now has support for variadic generics (TypeVarTuple) enabled by default, as an experimental feature. Refer to [PEP 646](https://peps.python.org/pep-0646/) for the details.
 
@@ -724,7 +724,7 @@ Changes included in this release:
  * Subtyping and inference of user-defined variadic types (Ivan Levkivskyi, PR [16076](https://github.com/python/mypy/pull/16076))
  * Complete type analysis of variadic types (Ivan Levkivskyi, PR [15991](https://github.com/python/mypy/pull/15991))
 
-#### New Way of Installing Mypyc Dependencies
+### New Way of Installing Mypyc Dependencies
 
 If you want to install package dependencies needed by mypyc (not just mypy), you should now install `mypy[mypyc]` instead of just `mypy`:
 
@@ -736,13 +736,13 @@ Mypy has many more users than mypyc, so always installing mypyc dependencies wou
 
 This change was contributed by Shantanu (PR [16229](https://github.com/python/mypy/pull/16229)).
 
-#### New Rules for Re-exports
+### New Rules for Re-exports
 
 Mypy no longer considers an import such as `import a.b as b` as an explicit re-export. The old behavior was arguably inconsistent and surprising. This may impact some stub packages, such as older versions of `types-six`. You can change the import to `from a import b as b`, if treating the import as a re-export was intentional.
 
 This change was contributed by Anders Kaseorg (PR [14086](https://github.com/python/mypy/pull/14086)).
 
-#### Improved Type Inference
+### Improved Type Inference
 
 The new type inference algorithm that was recently introduced to mypy (but was not enabled by default) is now enabled by default. It improves type inference of calls to generic callables where an argument is also a generic callable, in particular. You can use `--old-type-inference` to disable the new behavior.
 
@@ -750,7 +750,7 @@ The new algorithm can (rarely) produce different error messages, different error
 
 The new type inference algorithm was contributed by Ivan Levkivskyi. PR [16345](https://github.com/python/mypy/pull/16345) enabled it by default.
 
-#### Narrowing Tuple Types Using len()
+### Narrowing Tuple Types Using len()
 
 Mypy now can narrow tuple types using `len()` checks. Example:
 
@@ -763,7 +763,7 @@ def f(t: tuple[int, int] | tuple[int, int, int]) -> None:
 
 This feature was contributed by Ivan Levkivskyi (PR [16237](https://github.com/python/mypy/pull/16237)).
 
-#### More Precise Tuple Lengths (Experimental)
+### More Precise Tuple Lengths (Experimental)
 
 Mypy supports experimental, more precise checking of tuple type lengths through `--enable-incomplete-feature=PreciseTupleTypes`. Refer to the [documentation](https://mypy.readthedocs.io/en/latest/command_line.html#enabling-incomplete-experimental-features) for more information.
 
@@ -771,13 +771,13 @@ More generally, we are planning to use `--enable-incomplete-feature` to introduc
 
 This feature was contributed by Ivan Levkivskyi (PR [16237](https://github.com/python/mypy/pull/16237)).
 
-#### Mypy Changelog
+### Mypy Changelog
 
 We now maintain a [changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md) in the mypy Git repository. It mirrors the contents of [mypy release blog posts](https://mypy-lang.blogspot.com/). We will continue to also publish release blog posts. In the future, release blog posts will be created based on the changelog near a release date.
 
 This was contributed by Shantanu (PR [16280](https://github.com/python/mypy/pull/16280)).
 
-#### Mypy Daemon Improvements
+### Mypy Daemon Improvements
 
  * Fix daemon crash caused by deleted submodule (Jukka Lehtosalo, PR [16370](https://github.com/python/mypy/pull/16370))
  * Fix file reloading in dmypy with --export-types (Ivan Levkivskyi, PR [16359](https://github.com/python/mypy/pull/16359))
@@ -789,7 +789,7 @@ This was contributed by Shantanu (PR [16280](https://github.com/python/mypy/pull
  * Stream dmypy output instead of dumping everything at the end (Valentin Stanciu, PR [16252](https://github.com/python/mypy/pull/16252))
  * Make sure all dmypy errors are shown (Valentin Stanciu, PR [16250](https://github.com/python/mypy/pull/16250))
 
-#### Mypyc Improvements
+### Mypyc Improvements
 
  * Generate error on duplicate function definitions (Jukka Lehtosalo, PR [16309](https://github.com/python/mypy/pull/16309))
  * Don't crash on unreachable statements (Jukka Lehtosalo, PR [16311](https://github.com/python/mypy/pull/16311))
@@ -797,7 +797,7 @@ This was contributed by Shantanu (PR [16280](https://github.com/python/mypy/pull
  * Fix direct `__dict__` access on inner functions in new Python (Shantanu, PR [16084](https://github.com/python/mypy/pull/16084))
  * Make tuple packing and unpacking more efficient (Jukka Lehtosalo, PR [16022](https://github.com/python/mypy/pull/16022))
 
-#### Improvements to Error Reporting
+### Improvements to Error Reporting
 
  * Update starred expression error message to match CPython (Cibin Mathew, PR [16304](https://github.com/python/mypy/pull/16304))
  * Fix error code of "Maybe you forgot to use await" note (Jelle Zijlstra, PR [16203](https://github.com/python/mypy/pull/16203))
@@ -807,14 +807,14 @@ This was contributed by Shantanu (PR [16280](https://github.com/python/mypy/pull
  * Add hint for AsyncIterator incompatible return type (Ilya Priven, PR [15883](https://github.com/python/mypy/pull/15883))
  * Don't suggest stubs packages where the runtime package now ships with types (Alex Waygood, PR [16226](https://github.com/python/mypy/pull/16226))
 
-#### Performance Improvements
+### Performance Improvements
 
  * Speed up type argument checking (Jukka Lehtosalo, PR [16353](https://github.com/python/mypy/pull/16353))
  * Add fast path for checking self types (Jukka Lehtosalo, PR [16352](https://github.com/python/mypy/pull/16352))
  * Cache information about whether file is typeshed file (Jukka Lehtosalo, PR [16351](https://github.com/python/mypy/pull/16351))
  * Skip expensive `repr()` in logging call when not needed (Jukka Lehtosalo, PR [16350](https://github.com/python/mypy/pull/16350))
 
-#### Attrs and Dataclass Improvements
+### Attrs and Dataclass Improvements
 
  * `dataclass.replace`: Allow transformed classes (Ilya Priven, PR [15915](https://github.com/python/mypy/pull/15915))
  * `dataclass.replace`: Fall through to typeshed signature (Ilya Priven, PR [15962](https://github.com/python/mypy/pull/15962))
@@ -823,7 +823,7 @@ This was contributed by Shantanu (PR [16280](https://github.com/python/mypy/pull
  * `attrs`, `dataclasses`: Don't enforce slots when base class doesn't (Ilya Priven, PR [15976](https://github.com/python/mypy/pull/15976))
  * Fix crash on dataclass field / property collision (Nikita Sobolev, PR [16147](https://github.com/python/mypy/pull/16147))
 
-#### Stubgen Improvements
+### Stubgen Improvements
 
  * Write stubs with utf-8 encoding (Jørgen Lind, PR [16329](https://github.com/python/mypy/pull/16329))
  * Fix missing property setter in semantic analysis mode (Ali Hamdan, PR [16303](https://github.com/python/mypy/pull/16303))
@@ -831,7 +831,7 @@ This was contributed by Shantanu (PR [16280](https://github.com/python/mypy/pull
  * Multiple fixes to the generated imports (Ali Hamdan, PR [15624](https://github.com/python/mypy/pull/15624))
  * Generate valid dataclass stubs (Ali Hamdan, PR [15625](https://github.com/python/mypy/pull/15625))
 
-#### Fixes to Crashes
+### Fixes to Crashes
 
  * Fix incremental mode crash on TypedDict in method (Ivan Levkivskyi, PR [16364](https://github.com/python/mypy/pull/16364))
  * Fix crash on star unpack in TypedDict (Ivan Levkivskyi, PR [16116](https://github.com/python/mypy/pull/16116))
@@ -840,7 +840,7 @@ This was contributed by Shantanu (PR [16280](https://github.com/python/mypy/pull
  * Fix crash when parsing error code config with typo (Shantanu, PR [16005](https://github.com/python/mypy/pull/16005))
  * Fix `__post_init__()` internal error (Ilya Priven, PR [16080](https://github.com/python/mypy/pull/16080))
 
-#### Documentation Updates
+### Documentation Updates
 
  * Make it easier to copy commands from README (Hamir Mahal, PR [16133](https://github.com/python/mypy/pull/16133))
  * Document and rename `[overload-overlap]` error code (Shantanu, PR [16074](https://github.com/python/mypy/pull/16074))
@@ -848,7 +848,7 @@ This was contributed by Shantanu (PR [16280](https://github.com/python/mypy/pull
  * Document `force_union_syntax` and `force_uppercase_builtins` (Nikita Sobolev, PR [16048](https://github.com/python/mypy/pull/16048))
  * Document we're not tracking relationships between symbols (Ilya Priven, PR [16018](https://github.com/python/mypy/pull/16018))
 
-#### Other Notable Changes and Fixes
+### Other Notable Changes and Fixes
 
  * Propagate narrowed types to lambda expressions (Ivan Levkivskyi, PR [16407](https://github.com/python/mypy/pull/16407))
  * Avoid importing from `setuptools._distutils` (Shantanu, PR [16348](https://github.com/python/mypy/pull/16348))
@@ -882,11 +882,11 @@ This was contributed by Shantanu (PR [16280](https://github.com/python/mypy/pull
  * Make iterable logic more consistent (Shantanu, PR [16006](https://github.com/python/mypy/pull/16006))
  * Fix inference for properties with `__call__` (Shantanu, PR [15926](https://github.com/python/mypy/pull/15926))
 
-#### Typeshed Updates
+### Typeshed Updates
 
 Please see [git log](https://github.com/python/typeshed/commits/main?after=4a854366e03dee700109f8e758a08b2457ea2f51+0&branch=main&path=stdlib) for full list of standard library typeshed stub changes.
 
-#### Acknowledgements
+### Acknowledgements
 
 Thanks to all mypy contributors who contributed to this release:
 
@@ -932,7 +932,7 @@ We’ve just uploaded mypy 1.6 to the Python Package Index ([PyPI](https://pypi.
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### Introduce Error Subcodes for Import Errors
+### Introduce Error Subcodes for Import Errors
 
 Mypy now uses the error code import-untyped if an import targets an installed library that doesn’t support static type checking, and no stub files are available. Other invalid imports produce the import-not-found error code. They both are subcodes of the import error code, which was previously used for both kinds of import-related errors.
 
@@ -942,17 +942,17 @@ If you use \--warn-unused-ignore or \--strict, mypy will complain if you use \#
 
 This feature was contributed by Shantanu (PR [15840](https://github.com/python/mypy/pull/15840), PR [14740](https://github.com/python/mypy/pull/14740)).
 
-#### Remove Support for Targeting Python 3.6 and Earlier
+### Remove Support for Targeting Python 3.6 and Earlier
 
 Running mypy with \--python-version 3.6, for example, is no longer supported. Python 3.6 hasn’t been properly supported by mypy for some time now, and this makes it explicit. This was contributed by Nikita Sobolev (PR [15668](https://github.com/python/mypy/pull/15668)).
 
-#### Selective Filtering of \--disallow-untyped-calls Targets
+### Selective Filtering of \--disallow-untyped-calls Targets
 
 Using \--disallow-untyped-calls could be annoying when using libraries with missing type information, as mypy would generate many errors about code that uses the library. Now you can use \--untyped-calls-exclude=acme, for example, to disable these errors about calls targeting functions defined in the acme package. Refer to the [documentation](https://mypy.readthedocs.io/en/latest/command_line.html#cmdoption-mypy-untyped-calls-exclude) for more information.
 
 This feature was contributed by Ivan Levkivskyi (PR [15845](https://github.com/python/mypy/pull/15845)).
 
-#### Improved Type Inference between Callable Types
+### Improved Type Inference between Callable Types
 
 Mypy now does a better job inferring type variables inside arguments of callable types. For example, this code fragment now type checks correctly:
 
@@ -965,7 +965,7 @@ reveal_type(f(g))  # Callable[[str, int, int], None]
 
 This was contributed by Ivan Levkivskyi (PR [15910](https://github.com/python/mypy/pull/15910)).
 
-#### Don’t Consider None and TypeVar to Overlap in Overloads
+### Don’t Consider None and TypeVar to Overlap in Overloads
 
 Mypy now doesn’t consider an overload item with an argument type None to overlap with a type variable:
 
@@ -981,7 +981,7 @@ Previously mypy would generate an error about the definition of f above. This is
 
 This feature was contributed by Ivan Levkivskyi (PR [15846](https://github.com/python/mypy/pull/15846)).
 
-#### Improvements to \--new-type-inference
+### Improvements to \--new-type-inference
 
 The experimental new type inference algorithm (polymorphic inference) introduced as an opt-in feature in mypy 1.5 has several improvements:
 
@@ -993,7 +993,7 @@ The experimental new type inference algorithm (polymorphic inference) introduced
 
 **Note:** We are planning to enable \--new-type-inference by default in mypy 1.7. Please try this out and let us know if you encounter any issues.
 
-#### ParamSpec Improvements
+### ParamSpec Improvements
 
 *   Support self-types containing ParamSpec (Ivan Levkivskyi, PR [15903](https://github.com/python/mypy/pull/15903))
 *   Allow “…” in Concatenate, and clean up ParamSpec literals (Ivan Levkivskyi, PR [15905](https://github.com/python/mypy/pull/15905))
@@ -1002,12 +1002,12 @@ The experimental new type inference algorithm (polymorphic inference) introduced
 *   Fix crash on invalid type variable with ParamSpec (Ivan Levkivskyi, PR [15953](https://github.com/python/mypy/pull/15953))
 *   Fix subtyping between ParamSpecs (Ivan Levkivskyi, PR [15892](https://github.com/python/mypy/pull/15892))
 
-#### Stubgen Improvements
+### Stubgen Improvements
 
 *   Add option to include docstrings with stubgen (chylek, PR [13284](https://github.com/python/mypy/pull/13284))
 *   Add required ... initializer to NamedTuple fields with default values (Nikita Sobolev, PR [15680](https://github.com/python/mypy/pull/15680))
 
-#### Stubtest Improvements
+### Stubtest Improvements
 
 *   Fix \_\_mypy-replace false positives (Alex Waygood, PR [15689](https://github.com/python/mypy/pull/15689))
 *   Fix edge case for bytes enum subclasses (Alex Waygood, PR [15943](https://github.com/python/mypy/pull/15943))
@@ -1015,14 +1015,14 @@ The experimental new type inference algorithm (polymorphic inference) introduced
 *   Fixes to new check for missing stdlib modules (Alex Waygood, PR [15960](https://github.com/python/mypy/pull/15960))
 *   Fix stubtest enum.Flag edge case (Alex Waygood, PR [15933](https://github.com/python/mypy/pull/15933))
 
-#### Documentation Improvements
+### Documentation Improvements
 
 *   Do not advertise to create your own assert\_never helper (Nikita Sobolev, PR [15947](https://github.com/python/mypy/pull/15947))
 *   Fix all the missing references found within the docs (Albert Tugushev, PR [15875](https://github.com/python/mypy/pull/15875))
 *   Document await-not-async error code (Shantanu, PR [15858](https://github.com/python/mypy/pull/15858))
 *   Improve documentation of disabling error codes (Shantanu, PR [15841](https://github.com/python/mypy/pull/15841))
 
-#### Other Notable Changes and Fixes
+### Other Notable Changes and Fixes
 
 *   Make unsupported PEP 695 features (introduced in Python 3.12) give a reasonable error message (Shantanu, PR [16013](https://github.com/python/mypy/pull/16013))
 *   Remove the \--py2 command-line argument (Marc Mueller, PR [15670](https://github.com/python/mypy/pull/15670))
@@ -1045,11 +1045,11 @@ The experimental new type inference algorithm (polymorphic inference) introduced
 *   Add tox.ini to mypy sdist (Marcel Telka, PR [15853](https://github.com/python/mypy/pull/15853))
 *   Fix mypyc regression with pretty (Shantanu, PR [16124](https://github.com/python/mypy/pull/16124))
 
-#### Typeshed Updates
+### Typeshed Updates
 
 Typeshed is now modular and distributed as separate PyPI packages for everything except the standard library stubs. Please see [git log](https://github.com/python/typeshed/commits/main?after=6a8d653a671925b0a3af61729ff8cf3f90c9c662+0&branch=main&path=stdlib) for full list of typeshed changes.
 
-#### Acknowledgements
+### Acknowledgements
 
 Thanks to Max Murin, who did most of the release manager work for this release (I just did the final steps).
 
@@ -1088,11 +1088,11 @@ We’ve just uploaded mypy 1.5 to the Python Package Index ([PyPI](https://pypi.
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### Drop Support for Python 3.7
+### Drop Support for Python 3.7
 
 Mypy no longer supports running with Python 3.7, which has reached end-of-life. This was contributed by Shantanu (PR [15566](https://github.com/python/mypy/pull/15566)).
 
-#### Optional Check to Require Explicit @override
+### Optional Check to Require Explicit @override
 
 If you enable the explicit-override error code, mypy will generate an error if a method override doesn’t use the @typing.override decorator (as discussed in [PEP 698](https://peps.python.org/pep-0698/#strict-enforcement-per-project)). This way mypy will detect accidentally introduced overrides. Example:
 
@@ -1122,7 +1122,7 @@ The override decorator will be available in typing in Python 3.12, but you can a
 
 This feature was contributed by Marc Mueller(PR [15512](https://github.com/python/mypy/pull/15512)).
 
-#### More Flexible TypedDict Creation and Update
+### More Flexible TypedDict Creation and Update
 
 Mypy was previously overly strict when type checking TypedDict creation and update operations. Though these checks were often technically correct, they sometimes triggered for apparently valid code. These checks have now been relaxed by default. You can enable stricter checking by using the new \--extra-checks flag.
 
@@ -1150,11 +1150,11 @@ a.update(b)  # OK (previously an error)
 
 This feature was contributed by Ivan Levkivskyi (PR [15425](https://github.com/python/mypy/pull/15425)).
 
-#### Deprecated Flag: \--strict-concatenate
+### Deprecated Flag: \--strict-concatenate
 
 The behavior of \--strict-concatenate is now included in the new \--extra-checks flag, and the old flag is deprecated.
 
-#### Optionally Show Links to Error Code Documentation
+### Optionally Show Links to Error Code Documentation
 
 If you use \--show-error-code-links, mypy will add documentation links to (many) reported errors. The links are not shown for error messages that are sufficiently obvious, and they are shown once per error code only.
 
@@ -1165,19 +1165,19 @@ a.py:1: note: See https://mypy.rtfd.io/en/stable/_refs.html#code-var-annotated f
 ```
 This was contributed by Ivan Levkivskyi (PR [15449](https://github.com/python/mypy/pull/15449)).
 
-#### Consistently Avoid Type Checking Unreachable Code
+### Consistently Avoid Type Checking Unreachable Code
 
 If a module top level has unreachable code, mypy won’t type check the unreachable statements. This is consistent with how functions behave. The behavior of \--warn-unreachable is also more consistent now.
 
 This was contributed by Ilya Priven (PR [15386](https://github.com/python/mypy/pull/15386)).
 
-#### Experimental Improved Type Inference for Generic Functions
+### Experimental Improved Type Inference for Generic Functions
 
 You can use \--new-type-inference to opt into an experimental new type inference algorithm. It fixes issues when calling a generic functions with an argument that is also a generic function, in particular. This current implementation is still incomplete, but we encourage trying it out and reporting bugs if you encounter regressions. We are planning to enable the new algorithm by default in a future mypy release.
 
 This feature was contributed by Ivan Levkivskyi (PR [15287](https://github.com/python/mypy/pull/15287)).
 
-#### Partial Support for Python 3.12
+### Partial Support for Python 3.12
 
 Mypy and mypyc now support running on recent Python 3.12 development versions. Not all new Python 3.12 features are supported, and we don’t ship compiled wheels for Python 3.12 yet.
 
@@ -1193,7 +1193,7 @@ Mypy and mypyc now support running on recent Python 3.12 development versions. N
 *   mypyc: Don't use \_PyErr\_ChainExceptions on 3.12, since it's deprecated (Jukka Lehtosalo, PR [15468](https://github.com/python/mypy/pull/15468))
 *   mypyc: Add Python 3.12 feature macro (Jukka Lehtosalo, PR [15465](https://github.com/python/mypy/pull/15465))
 
-#### Improvements to Dataclasses
+### Improvements to Dataclasses
 
 *   Improve signature of dataclasses.replace (Ilya Priven, PR [14849](https://github.com/python/mypy/pull/14849))
 *   Fix dataclass/protocol crash on joining types (Ilya Priven, PR [15629](https://github.com/python/mypy/pull/15629))
@@ -1202,7 +1202,7 @@ Mypy and mypyc now support running on recent Python 3.12 development versions. N
 *   Add `__slots__` attribute to dataclasses (Nikita Sobolev, PR [15649](https://github.com/python/mypy/pull/15649))
 *   Support better \_\_post\_init\_\_ method signature for dataclasses (Nikita Sobolev, PR [15503](https://github.com/python/mypy/pull/15503))
 
-#### Mypyc Improvements
+### Mypyc Improvements
 
 *   Support unsigned 8-bit native integer type: mypy\_extensions.u8 (Jukka Lehtosalo, PR [15564](https://github.com/python/mypy/pull/15564))
 *   Support signed 16-bit native integer type: mypy\_extensions.i16 (Jukka Lehtosalo, PR [15464](https://github.com/python/mypy/pull/15464))
@@ -1212,20 +1212,20 @@ Mypy and mypyc now support running on recent Python 3.12 development versions. N
 *   Use C99 compound literals for undefined tuple values (Jukka Lehtosalo, PR [15453](https://github.com/python/mypy/pull/15453))
 *   Don't explicitly assign NULL values in setup functions (Logan Hunt, PR [15379](https://github.com/python/mypy/pull/15379))
 
-#### Stubgen Improvements
+### Stubgen Improvements
 
 *   Teach stubgen to work with complex and unary expressions (Nikita Sobolev, PR [15661](https://github.com/python/mypy/pull/15661))
 *   Support ParamSpec and TypeVarTuple (Ali Hamdan, PR [15626](https://github.com/python/mypy/pull/15626))
 *   Fix crash on non-str docstring (Ali Hamdan, PR [15623](https://github.com/python/mypy/pull/15623))
 
-#### Documentation Updates
+### Documentation Updates
 
 *   Add documentation for additional error codes (Ivan Levkivskyi, PR [15539](https://github.com/python/mypy/pull/15539))
 *   Improve documentation of type narrowing (Ilya Priven, PR [15652](https://github.com/python/mypy/pull/15652))
 *   Small improvements to protocol documentation (Shantanu, PR [15460](https://github.com/python/mypy/pull/15460))
 *   Remove confusing instance variable example in cheat sheet (Adel Atallah, PR [15441](https://github.com/python/mypy/pull/15441))
 
-#### Other Notable Fixes and Improvements
+### Other Notable Fixes and Improvements
 
 *   Constant fold additional unary and binary expressions (Richard Si, PR [15202](https://github.com/python/mypy/pull/15202))
 *   Exclude the same special attributes from Protocol as CPython (Kyle Benesch, PR [15490](https://github.com/python/mypy/pull/15490))
@@ -1245,11 +1245,11 @@ Mypy and mypyc now support running on recent Python 3.12 development versions. N
 *   Fix self types in subclass methods without Self annotation (Ivan Levkivskyi, PR [15541](https://github.com/python/mypy/pull/15541))
 *   Check for abstract class objects in tuples (Nikita Sobolev, PR [15366](https://github.com/python/mypy/pull/15366))
 
-#### Typeshed Updates
+### Typeshed Updates
 
 Typeshed is now modular and distributed as separate PyPI packages for everything except the standard library stubs. Please see [git log](https://github.com/python/typeshed/commits/main?after=fc7d4722eaa54803926cee5730e1f784979c0531+0&branch=main&path=stdlib) for full list of typeshed changes.
 
-#### Acknowledgements
+### Acknowledgements
 
 Thanks to all mypy contributors who contributed to this release:
 
@@ -1285,13 +1285,13 @@ We’ve just uploaded mypy 1.4 to the Python Package Index ([PyPI](https://pypi.
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### The Override Decorator
+### The Override Decorator
 
 Mypy can now ensure that when renaming a method, overrides are also renamed. You can explicitly mark a method as overriding a base class method by using the @typing.override decorator ([PEP 698](https://peps.python.org/pep-0698/)). If the method is then renamed in the base class while the method override is not, mypy will generate an error. The decorator will be available in typing in Python 3.12, but you can also use the backport from a recent version of `typing_extensions` on all supported Python versions.
 
 This feature was contributed byThomas M Kehrenberg (PR [14609](https://github.com/python/mypy/pull/14609)).
 
-#### Propagating Type Narrowing to Nested Functions
+### Propagating Type Narrowing to Nested Functions
 
 Previously, type narrowing was not propagated to nested functions because it would not be sound if the narrowed variable changed between the definition of the nested function and the call site. Mypy will now propagate the narrowed type if the variable is not assigned to after the definition of the nested function:
 
@@ -1311,7 +1311,7 @@ This may generate some new errors because asserts that were previously necessary
 
 This was contributed by Jukka Lehtosalo (PR [15133](https://github.com/python/mypy/pull/15133)).
 
-#### Narrowing Enum Values Using “==”
+### Narrowing Enum Values Using “==”
 
 Mypy now allows narrowing enum types using the \== operator. Previously this was only supported when using the is operator. This makes exhaustiveness checking with enum types more usable, as the requirement to use the is operator was not very intuitive. In this example mypy can detect that the developer forgot to handle the value MyEnum.C in example
 
@@ -1380,18 +1380,18 @@ def test_something() -> None:
 
 This feature was contributed by Shantanu (PR [11521](https://github.com/python/mypy/pull/11521)).
 
-#### Performance Improvements
+### Performance Improvements
 
 *   Speed up simplification of large union types and also fix a recursive tuple crash (Shantanu, PR [15128](https://github.com/python/mypy/pull/15128))
 *   Speed up union subtyping (Shantanu, PR [15104](https://github.com/python/mypy/pull/15104))
 *   Don't type check most function bodies when type checking third-party library code, or generally when ignoring errors (Jukka Lehtosalo, PR [14150](https://github.com/python/mypy/pull/14150))
 
-#### Improvements to Plugins
+### Improvements to Plugins
 
 *   attrs.evolve: Support generics and unions (Ilya Konstantinov, PR [15050](https://github.com/python/mypy/pull/15050))
 *   Fix ctypes plugin (Alex Waygood)
 
-#### Fixes to Crashes
+### Fixes to Crashes
 
 *   Fix a crash when function-scope recursive alias appears as upper bound (Ivan Levkivskyi, PR [15159](https://github.com/python/mypy/pull/15159))
 *   Fix crash on follow\_imports\_for\_stubs (Ivan Levkivskyi, PR [15407](https://github.com/python/mypy/pull/15407))
@@ -1405,7 +1405,7 @@ This feature was contributed by Shantanu (PR [11521](https://github.com/python/m
 *   Fix crash on lambda in generic context with generic method in body (Ivan Levkivskyi, PR [15155](https://github.com/python/mypy/pull/15155))
 *   Fix recursive type alias crash in make\_simplified\_union (Ivan Levkivskyi, PR [15216](https://github.com/python/mypy/pull/15216))
 
-#### Improvements to Error Messages
+### Improvements to Error Messages
 
 *   Use lower-case built-in collection types such as list\[…\] instead of List\[…\] in errors when targeting Python 3.9+ (Max Murin, PR [15070](https://github.com/python/mypy/pull/15070))
 *   Use X | Y union syntax in error messages when targeting Python 3.10+ (Omar Silva, PR [15102](https://github.com/python/mypy/pull/15102))
@@ -1418,7 +1418,7 @@ This feature was contributed by Shantanu (PR [11521](https://github.com/python/m
 *   Add explanation if argument type is incompatible because of an unsupported numbers type (Jukka Lehtosalo, PR [15137](https://github.com/python/mypy/pull/15137))
 *   Add more detail to 'signature incompatible with supertype' messages for non-callables (Ilya Priven, PR [15263](https://github.com/python/mypy/pull/15263))
 
-#### Documentation Updates
+### Documentation Updates
 
 *   Add \--local-partial-types note to dmypy docs (Alan Du, PR [15259](https://github.com/python/mypy/pull/15259))
 *   Update getting started docs for mypyc for Windows (Valentin Stanciu, PR [15233](https://github.com/python/mypy/pull/15233))
@@ -1426,13 +1426,13 @@ This feature was contributed by Shantanu (PR [11521](https://github.com/python/m
 *   Clarify difference between disallow\_untyped\_defs and disallow\_incomplete\_defs (Ilya Priven, PR [15247](https://github.com/python/mypy/pull/15247))
 *   Use attrs and @attrs.define in documentation and tests (Ilya Priven, PR [15152](https://github.com/python/mypy/pull/15152))
 
-#### Mypyc Improvements
+### Mypyc Improvements
 
 *   Fix unexpected TypeError for certain variables with an inferred optional type (Richard Si, PR [15206](https://github.com/python/mypy/pull/15206))
 *   Inline math literals (Logan Hunt, PR [15324](https://github.com/python/mypy/pull/15324))
 *   Support unpacking mappings in dict display (Richard Si, PR [15203](https://github.com/python/mypy/pull/15203))
 
-#### Changes to Stubgen
+### Changes to Stubgen
 
 *   Do not remove Generic from base classes (Ali Hamdan, PR [15316](https://github.com/python/mypy/pull/15316))
 *   Support yield from statements (Ali Hamdan, PR [15271](https://github.com/python/mypy/pull/15271))
@@ -1442,7 +1442,7 @@ This feature was contributed by Shantanu (PR [11521](https://github.com/python/m
 *   Make stubgen respect MYPY\_CACHE\_DIR (Henrik Bäärnhielm, PR [14722](https://github.com/python/mypy/pull/14722))
 *   Fixes and simplifications (Ali Hamdan, PR [15232](https://github.com/python/mypy/pull/15232))
 
-#### Other Notable Fixes and Improvements
+### Other Notable Fixes and Improvements
 
 *   Fix nested async functions when using TypeVar value restriction (Jukka Lehtosalo, PR [14705](https://github.com/python/mypy/pull/14705))
 *   Always allow returning Any from lambda (Ivan Levkivskyi, PR [15413](https://github.com/python/mypy/pull/15413))
@@ -1455,11 +1455,11 @@ This feature was contributed by Shantanu (PR [11521](https://github.com/python/m
 *   Fix match subject ignoring redefinitions (Vincent Vanlaer, PR [15306](https://github.com/python/mypy/pull/15306))
 *   Support `__all__`.remove (Shantanu, PR [15279](https://github.com/python/mypy/pull/15279))
 
-#### Typeshed Updates
+### Typeshed Updates
 
 Typeshed is now modular and distributed as separate PyPI packages for everything except the standard library stubs. Please see [git log](https://github.com/python/typeshed/commits/main?after=877e06ad1cfd9fd9967c0b0340a86d0c23ea89ce+0&branch=main&path=stdlib) for full list of typeshed changes.
 
-#### Acknowledgements
+### Acknowledgements
 
 Thanks to all mypy contributors who contributed to this release:
 
@@ -1515,12 +1515,12 @@ Posted by Jared Hance
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### Performance Improvements
+### Performance Improvements
 
 *   Improve performance of union subtyping (Shantanu, PR [15104](https://github.com/python/mypy/pull/15104))
 *   Add negative subtype caches (Ivan Levkivskyi, PR [14884](https://github.com/python/mypy/pull/14884))
 
-#### Stub Tooling Improvements
+### Stub Tooling Improvements
 
 *   Stubtest: Check that the stub is abstract if the runtime is, even when the stub is an overloaded method (Alex Waygood, PR [14955](https://github.com/python/mypy/pull/14955))
 *   Stubtest: Verify stub methods or properties are decorated with @final if they are decorated with @final at runtime (Alex Waygood, PR [14951](https://github.com/python/mypy/pull/14951))
@@ -1528,12 +1528,12 @@ You can read the full documentation for this release on [Read the Docs](http://m
 *   Stubgen: Support @functools.cached\_property (Nikita Sobolev, PR [14981](https://github.com/python/mypy/pull/14981))
 *   Improvements to stubgenc (Chad Dombrova, PR [14564](https://github.com/python/mypy/pull/14564))
 
-#### Improvements to attrs
+### Improvements to attrs
 
 *   Add support for converters with TypeVars on generic attrs classes (Chad Dombrova, PR [14908](https://github.com/python/mypy/pull/14908))
 *   Fix attrs.evolve on bound TypeVar (Ilya Konstantinov, PR [15022](https://github.com/python/mypy/pull/15022))
 
-#### Documentation Updates
+### Documentation Updates
 
 *   Improve async documentation (Shantanu, PR [14973](https://github.com/python/mypy/pull/14973))
 *   Improvements to cheat sheet (Shantanu, PR [14972](https://github.com/python/mypy/pull/14972))
@@ -1545,26 +1545,26 @@ You can read the full documentation for this release on [Read the Docs](http://m
 *   Fix alignment of cheat sheet example (Ondřej Cvacho, PR [15039](https://github.com/python/mypy/pull/15039))
 *   Fix error for callback protocol matching against callable type object (Shantanu, PR [15042](https://github.com/python/mypy/pull/15042))
 
-#### Error Reporting Improvements
+### Error Reporting Improvements
 
 *   Improve bytes formatting error (Shantanu, PR [14959](https://github.com/python/mypy/pull/14959))
 
-#### Mypyc Improvements
+### Mypyc Improvements
 
 *   Fix unions of bools and ints (Tomer Chachamu, PR [15066](https://github.com/python/mypy/pull/15066))
 
-#### Other Fixes and Improvements
+### Other Fixes and Improvements
 
 *   Fix narrowing union types that include Self with isinstance (Christoph Tyralla, PR [14923](https://github.com/python/mypy/pull/14923))
 *   Allow objects matching SupportsKeysAndGetItem to be unpacked (Bryan Forbes, PR [14990](https://github.com/python/mypy/pull/14990))
 *   Check type guard validity for staticmethods (EXPLOSION, PR [14953](https://github.com/python/mypy/pull/14953))
 *   Fix sys.platform when cross-compiling with emscripten (Ethan Smith, PR [14888](https://github.com/python/mypy/pull/14888))
 
-#### Typeshed Updates
+### Typeshed Updates
 
 Typeshed is now modular and distributed as separate PyPI packages for everything except the standard library stubs. Please see [git log](https://github.com/python/typeshed/commits/main?after=b0ed50e9392a23e52445b630a808153e0e256976+0&branch=main&path=stdlib) for full list of typeshed changes.
 
-#### Acknowledgements
+### Acknowledgements
 
 Thanks to all mypy contributors who contributed to this release:
 
@@ -1603,14 +1603,14 @@ We’ve just uploaded mypy 1.2 to the Python Package Index ([PyPI](https://pypi.
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### Improvements to Dataclass Transforms
+### Improvements to Dataclass Transforms
 
 *   Support implicit default for "init" parameter in field specifiers (Wesley Collin Wright and Jukka Lehtosalo, PR [15010](https://github.com/python/mypy/pull/15010))
 *   Support descriptors in dataclass transform (Jukka Lehtosalo, PR [15006](https://github.com/python/mypy/pull/15006))
 *   Fix frozen\_default in incremental mode (Wesley Collin Wright)
 *   Fix frozen behavior for base classes with direct metaclasses (Wesley Collin Wright, PR [14878](https://github.com/python/mypy/pull/14878))
 
-#### Mypyc: Native Floats
+### Mypyc: Native Floats
 
 Mypyc now uses a native, unboxed representation for values of type float. Previously these were heap-allocated Python objects. Native floats are faster and use less memory. Code that uses floating-point operations heavily can be several times faster when using native floats.
 
@@ -1649,7 +1649,7 @@ Related changes:
 *   Document native floats and integers (Jukka Lehtosalo, PR [14927](https://github.com/python/mypy/pull/14927))
 *   Fixes to float to int conversion (Jukka Lehtosalo, PR [14936](https://github.com/python/mypy/pull/14936))
 
-#### Mypyc: Native Integers
+### Mypyc: Native Integers
 
 Mypyc now supports signed 32-bit and 64-bit integer types in addition to the arbitrary-precision int type. You can use the types mypy\_extensions.i32 and mypy\_extensions.i64 to speed up code that uses integer operations heavily.
 
@@ -1663,33 +1663,33 @@ def inc(x: i64) -> i64:
 
 Refer to the [documentation](https://mypyc.readthedocs.io/en/latest/using_type_annotations.html#native-integer-types) for more information. This feature was contributed by Jukka Lehtosalo.
 
-#### Other Mypyc Fixes and Improvements
+### Other Mypyc Fixes and Improvements
 
 *   Support iterating over a TypedDict (Richard Si, PR [14747](https://github.com/python/mypy/pull/14747))
 *   Faster coercions between different tuple types (Jukka Lehtosalo, PR [14899](https://github.com/python/mypy/pull/14899))
 *   Faster calls via type aliases (Jukka Lehtosalo, PR [14784](https://github.com/python/mypy/pull/14784))
 *   Faster classmethod calls via cls (Jukka Lehtosalo, PR [14789](https://github.com/python/mypy/pull/14789))
 
-#### Fixes to Crashes
+### Fixes to Crashes
 
 *   Fix crash on class-level import in protocol definition (Ivan Levkivskyi, PR [14926](https://github.com/python/mypy/pull/14926))
 *   Fix crash on single item union of alias (Ivan Levkivskyi, PR [14876](https://github.com/python/mypy/pull/14876))
 *   Fix crash on ParamSpec in incremental mode (Ivan Levkivskyi, PR [14885](https://github.com/python/mypy/pull/14885))
 
-#### Documentation Updates
+### Documentation Updates
 
 *   Update adopting \--strict documentation for 1.0 (Shantanu, PR [14865](https://github.com/python/mypy/pull/14865))
 *   Some minor documentation tweaks (Jukka Lehtosalo, PR [14847](https://github.com/python/mypy/pull/14847))
 *   Improve documentation of top level mypy: disable-error-code comment (Nikita Sobolev, PR [14810](https://github.com/python/mypy/pull/14810))
 
-#### Error Reporting Improvements
+### Error Reporting Improvements
 
 *   Add error code to `typing_extensions` suggestion (Shantanu, PR [14881](https://github.com/python/mypy/pull/14881))
 *   Add a separate error code for top-level await (Nikita Sobolev, PR [14801](https://github.com/python/mypy/pull/14801))
 *   Don’t suggest two obsolete stub packages (Jelle Zijlstra, PR [14842](https://github.com/python/mypy/pull/14842))
 *   Add suggestions for pandas-stubs and lxml-stubs (Shantanu, PR [14737](https://github.com/python/mypy/pull/14737))
 
-#### Other Fixes and Improvements
+### Other Fixes and Improvements
 
 *   Multiple inheritance considers callable objects as subtypes of functions (Christoph Tyralla, PR [14855](https://github.com/python/mypy/pull/14855))
 *   stubtest: Respect @final runtime decorator and enforce it in stubs (Nikita Sobolev, PR [14922](https://github.com/python/mypy/pull/14922))
@@ -1708,11 +1708,11 @@ Refer to the [documentation](https://mypyc.readthedocs.io/en/latest/using_type_a
 *   Improve “used before definition” checks when a local definition has the same name as a global definition (Stas Ilinskiy, PR [14517](https://github.com/python/mypy/pull/14517))
 *   Honor NoReturn as \_\_setitem\_\_ return type to mark unreachable code (sterliakov, PR [12572](https://github.com/python/mypy/pull/12572))
 
-#### Typeshed Updates
+### Typeshed Updates
 
 Typeshed is now modular and distributed as separate PyPI packages for everything except the standard library stubs. Please see [git log](https://github.com/python/typeshed/commits/main?after=a544b75320e97424d2d927605316383c755cdac0+0&branch=main&path=stdlib) for full list of typeshed changes.
 
-#### Acknowledgements
+### Acknowledgements
 
 Thanks to all mypy contributors who contributed to this release:
 
@@ -1748,13 +1748,13 @@ Posted by Jukka Lehtosalo
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### Support for `dataclass_transform``
+### Support for `dataclass_transform``
 
 This release adds full support for the dataclass\_transform decorator defined in [PEP 681](https://peps.python.org/pep-0681/#decorator-function-example). This allows decorators, base classes, and metaclasses that generate a \_\_init\_\_ method or other methods based on the properties of that class (similar to dataclasses) to have those methods recognized by mypy.
 
 This was contributed by Wesley Collin Wright.
 
-#### Dedicated Error Code for Method Assignments
+### Dedicated Error Code for Method Assignments
 
 Mypy can’t safely check all assignments to methods (a form of monkey patching), so mypy generates an error by default. To make it easier to ignore this error, mypy now uses the new error code method-assign for this. By disabling this error code in a file or globally, mypy will no longer complain about assignments to methods if the signatures are compatible.
 
@@ -1762,16 +1762,16 @@ Mypy also supports the old error code assignment for these assignments to preven
 
 This was contributed by Ivan Levkivskyi (PR [14570](https://github.com/python/mypy/pull/14570)).
 
-#### Fixes to Crashes
+### Fixes to Crashes
 
 *   Fix a crash on walrus in comprehension at class scope (Ivan Levkivskyi, PR [14556](https://github.com/python/mypy/pull/14556))
 *   Fix crash related to value-constrained TypeVar (Shantanu, PR [14642](https://github.com/python/mypy/pull/14642))
 
-#### Fixes to Cache Corruption
+### Fixes to Cache Corruption
 
 *   Fix generic TypedDict/NamedTuple caching (Ivan Levkivskyi, PR [14675](https://github.com/python/mypy/pull/14675))
 
-#### Mypyc Fixes and Improvements
+### Mypyc Fixes and Improvements
 
 *   Raise "non-trait base must be first..." error less frequently (Richard Si, PR [14468](https://github.com/python/mypy/pull/14468))
 *   Generate faster code for bool comparisons and arithmetic (Jukka Lehtosalo, PR [14489](https://github.com/python/mypy/pull/14489))
@@ -1782,12 +1782,12 @@ This was contributed by Ivan Levkivskyi (PR [14570](https://github.com/python/my
 *   Fix crash on star unpacking to underscore (Ivan Levkivskyi, PR [14624](https://github.com/python/mypy/pull/14624))
 *   Fix iterating over a union of dicts (Richard Si, PR [14713](https://github.com/python/mypy/pull/14713))
 
-#### Fixes to Detecting Undefined Names (used-before-def)
+### Fixes to Detecting Undefined Names (used-before-def)
 
 *   Correctly handle walrus operator (Stas Ilinskiy, PR [14646](https://github.com/python/mypy/pull/14646))
 *   Handle walrus declaration in match subject correctly (Stas Ilinskiy, PR [14665](https://github.com/python/mypy/pull/14665))
 
-#### Stubgen Improvements
+### Stubgen Improvements
 
 Stubgen is a tool for automatically generating draft stubs for libraries.
 
@@ -1795,14 +1795,14 @@ Stubgen is a tool for automatically generating draft stubs for libraries.
 *   Fix crash with PEP 604 union in type variable bound (Shantanu, PR [14557](https://github.com/python/mypy/pull/14557))
 *   Preserve PEP 604 unions in generated .pyi files (hamdanal, PR [14601](https://github.com/python/mypy/pull/14601))
 
-#### Stubtest Improvements
+### Stubtest Improvements
 
 Stubtest is a tool for testing that stubs conform to the implementations.
 
 *   Update message format so that it’s easier to go to error location (Avasam, PR [14437](https://github.com/python/mypy/pull/14437))
 *   Handle name-mangling edge cases better (Alex Waygood, PR [14596](https://github.com/python/mypy/pull/14596))
 
-#### Changes to Error Reporting and Messages
+### Changes to Error Reporting and Messages
 
 *   Add new TypedDict error code typeddict-unknown-key (JoaquimEsteves, PR [14225](https://github.com/python/mypy/pull/14225))
 *   Give arguments a more reasonable location in error messages (Max Murin, PR [14562](https://github.com/python/mypy/pull/14562))
@@ -1814,7 +1814,7 @@ Stubtest is a tool for testing that stubs conform to the implementations.
 *   Adjust inconsistent dataclasses plugin error messages (Wesley Collin Wright, PR [14637](https://github.com/python/mypy/pull/14637))
 *   Consolidate literal bool argument error messages (Wesley Collin Wright, PR [14693](https://github.com/python/mypy/pull/14693))
 
-#### Other Fixes and Improvements
+### Other Fixes and Improvements
 
 *   Check that type guards accept a positional argument (EXPLOSION, PR [14238](https://github.com/python/mypy/pull/14238))
 *   Fix bug with in operator used with a union of Container and Iterable (Max Murin, PR [14384](https://github.com/python/mypy/pull/14384))
@@ -1822,11 +1822,11 @@ Stubtest is a tool for testing that stubs conform to the implementations.
 *   Allow overlapping comparisons between bytes-like types (Shantanu, PR [14658](https://github.com/python/mypy/pull/14658))
 *   Fix mypy daemon documentation link in README (Ivan Levkivskyi, PR [14644](https://github.com/python/mypy/pull/14644))
 
-#### Typeshed Updates
+### Typeshed Updates
 
 Typeshed is now modular and distributed as separate PyPI packages for everything except the standard library stubs. Please see [git log](https://github.com/python/typeshed/commits/main?after=5ebf892d0710a6e87925b8d138dfa597e7bb11cc+0&branch=main&path=stdlib) for full list of typeshed changes.
 
-#### Acknowledgements
+### Acknowledgements
 
 Thanks to all mypy contributors who contributed to this release:
 
@@ -1868,7 +1868,7 @@ We’ve just uploaded mypy 1.0 to the Python Package Index ([PyPI](https://pypi.
 
 You can read the full documentation for this release on [Read the Docs](http://mypy.readthedocs.io).
 
-#### New Release Versioning Scheme
+### New Release Versioning Scheme
 
 Now that mypy reached 1.0, we’ll switch to a new versioning scheme. Mypy version numbers will be of form x.y.z.
 
@@ -1884,7 +1884,7 @@ Any significant backward incompatible change must be announced in the blog post
 
 See [”Release Process” in the mypy wiki](https://github.com/python/mypy/wiki/Release-Process) for more details and for the most up-to-date version of the versioning scheme.
 
-#### Performance Improvements
+### Performance Improvements
 
 Mypy 1.0 is up to 40% faster than mypy 0.991 when type checking the Dropbox internal codebase. We also set up a daily job to measure the performance of the most recent development version of mypy to make it easier to track changes in performance.
 
@@ -1911,7 +1911,7 @@ Many optimizations contributed to this improvement:
 *   Speed up freshening type variables (Jukka Lehtosalo, PR [14323](https://github.com/python/mypy/pull/14323))
 *   Optimize implementation of TypedDict types for \*\*kwds (Jukka Lehtosalo, PR [14316](https://github.com/python/mypy/pull/14316))
 
-#### Warn About Variables Used Before Definition
+### Warn About Variables Used Before Definition
 
 Mypy will now generate an error if you use a variable before it’s defined. This feature is enabled by default. By default mypy reports an error when it infers that a variable is always undefined.
 ```python
@@ -1920,7 +1920,7 @@ x = 0
 ```
 This feature was contributed by Stas Ilinskiy.
 
-#### Detect Possibly Undefined Variables (Experimental)
+### Detect Possibly Undefined Variables (Experimental)
 
 A new experimental possibly-undefined error code is now available that will detect variables that may be undefined:
 ```python
@@ -1932,7 +1932,7 @@ The error code is disabled be default, since it can generate false positives.
 
 This feature was contributed by Stas Ilinskiy.
 
-#### Support the “Self” Type
+### Support the “Self” Type
 
 There is now a simpler syntax for declaring [generic self types](https://mypy.readthedocs.io/en/stable/generics.html#generic-methods-and-generic-self) introduced in [PEP 673](https://peps.python.org/pep-0673/): the Self type. You no longer have to define a type variable to use “self types”, and you can use them with attributes. Example from mypy documentation:
 ```python
@@ -1958,7 +1958,7 @@ The feature was introduced in Python 3.11. In earlier Python versions a backport
 
 This was contributed by Ivan Levkivskyi (PR [14041](https://github.com/python/mypy/pull/14041)).
 
-#### Support ParamSpec in Type Aliases
+### Support ParamSpec in Type Aliases
 
 ParamSpec and Concatenate can now be used in type aliases. Example:
 ```python
@@ -1972,11 +1972,11 @@ def f(c: A[int, str]) -> None:
 ```
 This feature was contributed by Ivan Levkivskyi (PR [14159](https://github.com/python/mypy/pull/14159)).
 
-#### ParamSpec and Generic Self Types No Longer Experimental
+### ParamSpec and Generic Self Types No Longer Experimental
 
 Support for ParamSpec ([PEP 612](https://www.python.org/dev/peps/pep-0612/)) and generic self types are no longer considered experimental.
 
-#### Miscellaneous New Features
+### Miscellaneous New Features
 
 *   Minimal, partial implementation of dataclass\_transform ([PEP 681](https://peps.python.org/pep-0681/)) (Wesley Collin Wright, PR [14523](https://github.com/python/mypy/pull/14523))
 *   Add basic support for `typing_extensions`.TypeVar (Marc Mueller, PR [14313](https://github.com/python/mypy/pull/14313))
@@ -1989,7 +1989,7 @@ Support for ParamSpec ([PEP 612](https://www.python.org/dev/peps/pep-0612/)) and
 *   Generate error for class attribute access if attribute is defined with `__slots__` (Harrison McCarty, PR [14125](https://github.com/python/mypy/pull/14125))
 *   Support additional attributes in callback protocols (Ivan Levkivskyi, PR [14084](https://github.com/python/mypy/pull/14084))
 
-#### Fixes to Crashes
+### Fixes to Crashes
 
 *   Fix crash on prefixed ParamSpec with forward reference (Ivan Levkivskyi, PR [14569](https://github.com/python/mypy/pull/14569))
 *   Fix internal crash when resolving the same partial type twice (Shantanu, PR [14552](https://github.com/python/mypy/pull/14552))
@@ -2009,19 +2009,19 @@ Support for ParamSpec ([PEP 612](https://www.python.org/dev/peps/pep-0612/)) and
 *   Fix crash with enums (Michael Lee, PR [14021](https://github.com/python/mypy/pull/14021))
 *   Fix crash with malformed TypedDicts and disllow-any-expr (Michael Lee, PR [13963](https://github.com/python/mypy/pull/13963))
 
-#### Error Reporting Improvements
+### Error Reporting Improvements
 
 *   More helpful error for missing self (Shantanu, PR [14386](https://github.com/python/mypy/pull/14386))
 *   Add error-code truthy-iterable (Marc Mueller, PR [13762](https://github.com/python/mypy/pull/13762))
 *   Fix pluralization in error messages (KotlinIsland, PR [14411](https://github.com/python/mypy/pull/14411))
 
-#### Mypyc: Support Match Statement
+### Mypyc: Support Match Statement
 
 Mypyc can now compile Python 3.10 match statements.
 
 This was contributed by dosisod (PR [13953](https://github.com/python/mypy/pull/13953)).
 
-#### Other Mypyc Fixes and Improvements
+### Other Mypyc Fixes and Improvements
 
 *   Optimize int(x)/float(x)/complex(x) on instances of native classes (Richard Si, PR [14450](https://github.com/python/mypy/pull/14450))
 *   Always emit warnings (Richard Si, PR [14451](https://github.com/python/mypy/pull/14451))
@@ -2037,7 +2037,7 @@ This was contributed by dosisod (PR [13953](https://github.com/python/mypy/pull/
 *   Allow use of enum.Enum (Shantanu, PR [13995](https://github.com/python/mypy/pull/13995))
 *   Fix compiling on Arch Linux (dosisod, PR [13978](https://github.com/python/mypy/pull/13978))
 
-#### Documentation Improvements
+### Documentation Improvements
 
 *   Various documentation and error message tweaks (Jukka Lehtosalo, PR [14574](https://github.com/python/mypy/pull/14574))
 *   Improve Generics documentation (Shantanu, PR [14587](https://github.com/python/mypy/pull/14587))
@@ -2057,7 +2057,7 @@ This was contributed by dosisod (PR [13953](https://github.com/python/mypy/pull/
 *   Flycheck-mypy is deprecated, since its functionality was merged to Flycheck (Ivan Levkivskyi, PR [14247](https://github.com/python/mypy/pull/14247))
 *   Update code example in "Declaring decorators" (ChristianWitzler, PR [14131](https://github.com/python/mypy/pull/14131))
 
-#### Stubtest Improvements
+### Stubtest Improvements
 
 Stubtest is a tool for testing that stubs conform to the implementations.
 
@@ -2068,13 +2068,13 @@ Stubtest is a tool for testing that stubs conform to the implementations.
 *   Add \_\_warningregistry\_\_ to the list of ignored module dunders (Nikita Sobolev, PR [14218](https://github.com/python/mypy/pull/14218))
 *   If a default is present in the stub, check that it is correct (Jelle Zijlstra, PR [14085](https://github.com/python/mypy/pull/14085))
 
-#### Stubgen Improvements
+### Stubgen Improvements
 
 Stubgen is a tool for automatically generating draft stubs for libraries.
 
 *   Treat dlls as C modules (Shantanu, PR [14503](https://github.com/python/mypy/pull/14503))
 
-#### Other Notable Fixes and Improvements
+### Other Notable Fixes and Improvements
 
 *   Update stub suggestions based on recent typeshed changes (Alex Waygood, PR [14265](https://github.com/python/mypy/pull/14265))
 *   Fix attrs protocol check with cache (Marc Mueller, PR [14558](https://github.com/python/mypy/pull/14558))
@@ -2113,11 +2113,11 @@ Stubgen is a tool for automatically generating draft stubs for libraries.
 *   Improve handling of redefinitions through imports (Shantanu, PR [13969](https://github.com/python/mypy/pull/13969))
 *   Preserve (some) implicitly exported types (Shantanu, PR [13967](https://github.com/python/mypy/pull/13967))
 
-#### Typeshed Updates
+### Typeshed Updates
 
 Typeshed is now modular and distributed as separate PyPI packages for everything except the standard library stubs. Please see [git log](https://github.com/python/typeshed/commits/main?after=ea0ae2155e8a04c9837903c3aff8dd5ad5f36ebc+0&branch=main&path=stdlib) for full list of typeshed changes.
 
-#### Acknowledgements
+### Acknowledgements
 
 Thanks to all mypy contributors who contributed to this release:
 
diff --git a/docs/requirements-docs.txt b/docs/requirements-docs.txt
index a3504b07824d..dc502d121ffc 100644
--- a/docs/requirements-docs.txt
+++ b/docs/requirements-docs.txt
@@ -1,2 +1,3 @@
 sphinx>=5.1.0
 furo>=2022.3.4
+myst-parser>=4.0.0
diff --git a/docs/source/additional_features.rst b/docs/source/additional_features.rst
index ae625c157654..e7c162a0b0df 100644
--- a/docs/source/additional_features.rst
+++ b/docs/source/additional_features.rst
@@ -46,21 +46,18 @@ define dataclasses. For example:
     UnorderedPoint(1, 2) < UnorderedPoint(3, 4)  # Error: Unsupported operand types
 
 Dataclasses can be generic and can be used in any other way a normal
-class can be used:
+class can be used (Python 3.12 syntax):
 
 .. code-block:: python
 
     from dataclasses import dataclass
-    from typing import Generic, TypeVar
-
-    T = TypeVar('T')
 
     @dataclass
-    class BoxedData(Generic[T]):
+    class BoxedData[T]:
         data: T
         label: str
 
-    def unbox(bd: BoxedData[T]) -> T:
+    def unbox[T](bd: BoxedData[T]) -> T:
         ...
 
     val = unbox(BoxedData(42, "<important>"))  # OK, inferred type is int
@@ -98,17 +95,16 @@ does **not** work:
 
 
 To have Mypy recognize a wrapper of :py:func:`dataclasses.dataclass <dataclasses.dataclass>`
-as a dataclass decorator, consider using the :py:func:`~typing.dataclass_transform` decorator:
+as a dataclass decorator, consider using the :py:func:`~typing.dataclass_transform`
+decorator (example uses Python 3.12 syntax):
 
 .. code-block:: python
 
     from dataclasses import dataclass, Field
-    from typing import TypeVar, dataclass_transform
-
-    T = TypeVar('T')
+    from typing import dataclass_transform
 
     @dataclass_transform(field_specifiers=(Field,))
-    def my_dataclass(cls: type[T]) -> type[T]:
+    def my_dataclass[T](cls: type[T]) -> type[T]:
         ...
         return dataclass(cls)
 
@@ -367,20 +363,20 @@ Extended Callable types
    This feature is deprecated.  You can use
    :ref:`callback protocols <callback_protocols>` as a replacement.
 
-As an experimental mypy extension, you can specify :py:data:`~typing.Callable` types
+As an experimental mypy extension, you can specify :py:class:`~collections.abc.Callable` types
 that support keyword arguments, optional arguments, and more.  When
-you specify the arguments of a :py:data:`~typing.Callable`, you can choose to supply just
+you specify the arguments of a :py:class:`~collections.abc.Callable`, you can choose to supply just
 the type of a nameless positional argument, or an "argument specifier"
 representing a more complicated form of argument.  This allows one to
 more closely emulate the full range of possibilities given by the
 ``def`` statement in Python.
 
 As an example, here's a complicated function definition and the
-corresponding :py:data:`~typing.Callable`:
+corresponding :py:class:`~collections.abc.Callable`:
 
 .. code-block:: python
 
-   from typing import Callable
+   from collections.abc import Callable
    from mypy_extensions import (Arg, DefaultArg, NamedArg,
                                 DefaultNamedArg, VarArg, KwArg)
 
@@ -453,7 +449,7 @@ purpose:
 In all cases, the ``type`` argument defaults to ``Any``, and if the
 ``name`` argument is omitted the argument has no name (the name is
 required for ``NamedArg`` and ``DefaultNamedArg``).  A basic
-:py:data:`~typing.Callable` such as
+:py:class:`~collections.abc.Callable` such as
 
 .. code-block:: python
 
@@ -465,7 +461,7 @@ is equivalent to the following:
 
    MyFunc = Callable[[Arg(int), Arg(str), Arg(int)], float]
 
-A :py:data:`~typing.Callable` with unspecified argument types, such as
+A :py:class:`~collections.abc.Callable` with unspecified argument types, such as
 
 .. code-block:: python
 
diff --git a/docs/source/changelog.md b/docs/source/changelog.md
new file mode 100644
index 000000000000..a490ada727a6
--- /dev/null
+++ b/docs/source/changelog.md
@@ -0,0 +1,3 @@
+<!-- This file includes mypy/CHANGELOG.md into mypy documentation -->
+```{include} ../../CHANGELOG.md
+```
diff --git a/docs/source/cheat_sheet_py3.rst b/docs/source/cheat_sheet_py3.rst
index b8e43960fd09..7385a66863bf 100644
--- a/docs/source/cheat_sheet_py3.rst
+++ b/docs/source/cheat_sheet_py3.rst
@@ -72,9 +72,9 @@ Useful built-in types
    # On earlier versions, use Union
    x: list[Union[int, str]] = [3, 5, "test", "fun"]
 
-   # Use Optional[X] for a value that could be None
-   # Optional[X] is the same as X | None or Union[X, None]
-   x: Optional[str] = "something" if some_condition() else None
+   # Use X | None for a value that could be None on Python 3.10+
+   # Use Optional[X] on 3.9 and earlier; Optional[X] is the same as 'X | None'
+   x: str | None = "something" if some_condition() else None
    if x is not None:
        # Mypy understands x won't be None here because of the if-statement
        print(x.upper())
@@ -88,7 +88,8 @@ Functions
 
 .. code-block:: python
 
-   from typing import Callable, Iterator, Union, Optional
+   from collections.abc import Iterator, Callable
+   from typing import Union, Optional
 
    # This is how you annotate a function definition
    def stringify(num: int) -> str:
@@ -121,13 +122,14 @@ Functions
            i += 1
 
    # You can of course split a function annotation over multiple lines
-   def send_email(address: Union[str, list[str]],
-                  sender: str,
-                  cc: Optional[list[str]],
-                  bcc: Optional[list[str]],
-                  subject: str = '',
-                  body: Optional[list[str]] = None
-                  ) -> bool:
+   def send_email(
+       address: str | list[str],
+       sender: str,
+       cc: list[str] | None,
+       bcc: list[str] | None,
+       subject: str = '',
+       body: list[str] | None = None,
+   ) -> bool:
        ...
 
    # Mypy understands positional-only and keyword-only arguments
@@ -230,7 +232,7 @@ When you're puzzled or when things are complicated
    # If you initialize a variable with an empty container or "None"
    # you may have to help mypy a bit by providing an explicit type annotation
    x: list[str] = []
-   x: Optional[str] = None
+   x: str | None = None
 
    # Use Any if you don't know the type of something or it's too
    # dynamic to write a type for
@@ -274,7 +276,8 @@ that are common in idiomatic Python are standardized.
 
 .. code-block:: python
 
-   from typing import Mapping, MutableMapping, Sequence, Iterable
+   from collections.abc import Mapping, MutableMapping, Sequence, Iterable
+   # or 'from typing import ...' (required in Python 3.8)
 
    # Use Iterable for generic iterables (anything usable in "for"),
    # and Sequence where a sequence (supporting "len" and "__getitem__") is
@@ -349,11 +352,26 @@ Decorators
 **********
 
 Decorator functions can be expressed via generics. See
-:ref:`declaring-decorators` for more details.
+:ref:`declaring-decorators` for more details. Example using Python 3.12
+syntax:
+
+.. code-block:: python
+
+    from collections.abc import Callable
+    from typing import Any
+
+    def bare_decorator[F: Callable[..., Any]](func: F) -> F:
+        ...
+
+    def decorator_args[F: Callable[..., Any]](url: str) -> Callable[[F], F]:
+        ...
+
+The same example using pre-3.12 syntax:
 
 .. code-block:: python
 
-    from typing import Any, Callable, TypeVar
+    from collections.abc import Callable
+    from typing import Any, TypeVar
 
     F = TypeVar('F', bound=Callable[..., Any])
 
diff --git a/docs/source/class_basics.rst b/docs/source/class_basics.rst
index 1d80da5830ec..241dbeae0f44 100644
--- a/docs/source/class_basics.rst
+++ b/docs/source/class_basics.rst
@@ -152,7 +152,8 @@ between class and instance variables with callable types. For example:
 
 .. code-block:: python
 
-   from typing import Callable, ClassVar
+   from collections.abc import Callable
+   from typing import ClassVar
 
    class A:
        foo: Callable[[int], None]
diff --git a/docs/source/command_line.rst b/docs/source/command_line.rst
index c085b63107b0..062739540ade 100644
--- a/docs/source/command_line.rst
+++ b/docs/source/command_line.rst
@@ -420,11 +420,11 @@ The following flags adjust how mypy handles values of type ``None``.
 
 .. option:: --implicit-optional
 
-    This flag causes mypy to treat arguments with a ``None``
-    default value as having an implicit :py:data:`~typing.Optional` type.
+    This flag causes mypy to treat parameters with a ``None``
+    default value as having an implicit optional type (``T | None``).
 
     For example, if this flag is set, mypy would assume that the ``x``
-    parameter is actually of type ``Optional[int]`` in the code snippet below
+    parameter is actually of type ``int | None`` in the code snippet below,
     since the default parameter is ``None``:
 
     .. code-block:: python
@@ -438,7 +438,7 @@ The following flags adjust how mypy handles values of type ``None``.
 
 .. option:: --no-strict-optional
 
-    This flag effectively disables checking of :py:data:`~typing.Optional`
+    This flag effectively disables checking of optional
     types and ``None`` values. With this option, mypy doesn't
     generally check the use of ``None`` values -- it is treated
     as compatible with every type.
@@ -575,26 +575,24 @@ of the above sections.
 .. option:: --local-partial-types
 
     In mypy, the most common cases for partial types are variables initialized using ``None``,
-    but without explicit ``Optional`` annotations. By default, mypy won't check partial types
+    but without explicit ``X | None`` annotations. By default, mypy won't check partial types
     spanning module top level or class top level. This flag changes the behavior to only allow
     partial types at local level, therefore it disallows inferring variable type for ``None``
     from two assignments in different scopes. For example:
 
     .. code-block:: python
 
-        from typing import Optional
-
         a = None  # Need type annotation here if using --local-partial-types
-        b: Optional[int] = None
+        b: int | None = None
 
         class Foo:
             bar = None  # Need type annotation here if using --local-partial-types
-            baz: Optional[int] = None
+            baz: int | None = None
 
             def __init__(self) -> None:
                 self.bar = 1
 
-        reveal_type(Foo().bar)  # Union[int, None] without --local-partial-types
+        reveal_type(Foo().bar)  # 'int | None' without --local-partial-types
 
     Note: this option is always implicitly enabled in mypy daemon and will become
     enabled by default for mypy in a future release.
@@ -630,13 +628,11 @@ of the above sections.
 
     .. code-block:: python
 
-       from typing import Text
-
        items: list[int]
        if 'some string' in items:  # Error: non-overlapping container check!
            ...
 
-       text: Text
+       text: str
        if text != b'other bytes':  # Error: non-overlapping equality check!
            ...
 
@@ -1008,7 +1004,7 @@ format into the specified directory.
 Enabling incomplete/experimental features
 *****************************************
 
-.. option:: --enable-incomplete-feature {PreciseTupleTypes, NewGenericSyntax, InlineTypedDict}
+.. option:: --enable-incomplete-feature {PreciseTupleTypes, InlineTypedDict}
 
     Some features may require several mypy releases to implement, for example
     due to their complexity, potential for backwards incompatibility, or
@@ -1055,19 +1051,6 @@ List of currently incomplete/experimental features:
          # Without PreciseTupleTypes: tuple[int, ...]
          # With PreciseTupleTypes: tuple[()] | tuple[int] | tuple[int, int]
 
-* ``NewGenericSyntax``: this feature enables support for syntax defined
-  by :pep:`695`. For example:
-
-  .. code-block:: python
-
-     class Container[T]:  # defines a generic class
-         content: T
-
-     def first[T](items: list[T]) -> T:  # defines a generic function
-         return items[0]
-
-     type Items[T] = list[tuple[T, T]]  # defines a generic type alias
-
 * ``InlineTypedDict``: this feature enables non-standard syntax for inline
   :ref:`TypedDicts <typeddict>`, for example:
 
diff --git a/docs/source/common_issues.rst b/docs/source/common_issues.rst
index cfe82e19e77b..39954b8e332a 100644
--- a/docs/source/common_issues.rst
+++ b/docs/source/common_issues.rst
@@ -363,7 +363,8 @@ explicit type cast:
 
 .. code-block:: python
 
-  from typing import Sequence, cast
+  from collections.abc import Sequence
+  from typing import cast
 
   def find_first_str(a: Sequence[object]) -> str:
       index = next((i for i, s in enumerate(a) if isinstance(s, str)), -1)
@@ -700,7 +701,7 @@ This example demonstrates both safe and unsafe overrides:
 
 .. code-block:: python
 
-    from typing import Sequence, List, Iterable
+    from collections.abc import Sequence, Iterable
 
     class A:
         def test(self, t: Sequence[int]) -> Sequence[str]:
@@ -713,7 +714,7 @@ This example demonstrates both safe and unsafe overrides:
 
     class NarrowerArgument(A):
         # A more specific argument type isn't accepted
-        def test(self, t: List[int]) -> Sequence[str]:  # Error
+        def test(self, t: list[int]) -> Sequence[str]:  # Error
             ...
 
     class NarrowerReturn(A):
@@ -802,7 +803,7 @@ This is best understood via an example:
 
 .. code-block:: python
 
-    def foo(x: Optional[int]) -> Callable[[], int]:
+    def foo(x: int | None) -> Callable[[], int]:
         if x is None:
             x = 5
         print(x + 1)  # mypy correctly deduces x must be an int here
diff --git a/docs/source/conf.py b/docs/source/conf.py
index 5934c7474536..f8faa03a09b2 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -35,7 +35,7 @@
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
-extensions = ["sphinx.ext.intersphinx", "docs.source.html_builder"]
+extensions = ["sphinx.ext.intersphinx", "docs.source.html_builder", "myst_parser"]
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ["_templates"]
diff --git a/docs/source/config_file.rst b/docs/source/config_file.rst
index b0e82a33255a..ded8476b60e3 100644
--- a/docs/source/config_file.rst
+++ b/docs/source/config_file.rst
@@ -574,8 +574,8 @@ section of the command line docs.
     :type: boolean
     :default: False
 
-    Causes mypy to treat arguments with a ``None``
-    default value as having an implicit :py:data:`~typing.Optional` type.
+    Causes mypy to treat parameters with a ``None``
+    default value as having an implicit optional type (``T | None``).
 
     **Note:** This was True by default in mypy versions 0.980 and earlier.
 
@@ -584,7 +584,7 @@ section of the command line docs.
     :type: boolean
     :default: True
 
-    Effectively disables checking of :py:data:`~typing.Optional`
+    Effectively disables checking of optional
     types and ``None`` values. With this option, mypy doesn't
     generally check the use of ``None`` values -- it is treated
     as compatible with every type.
diff --git a/docs/source/dynamic_typing.rst b/docs/source/dynamic_typing.rst
index d3476de2ca64..1c31a535bdc1 100644
--- a/docs/source/dynamic_typing.rst
+++ b/docs/source/dynamic_typing.rst
@@ -81,9 +81,7 @@ treated as ``Any``:
 
 .. code-block:: python
 
-    from typing import List
-
-    def f(x: List) -> None:
+    def f(x: list) -> None:
         reveal_type(x)        # Revealed type is "builtins.list[Any]"
         reveal_type(x[0])     # Revealed type is "Any"
         x[0].anything_goes()  # OK
diff --git a/docs/source/error_code_list.rst b/docs/source/error_code_list.rst
index 85c8d437a856..2739894dd3ec 100644
--- a/docs/source/error_code_list.rst
+++ b/docs/source/error_code_list.rst
@@ -59,8 +59,6 @@ Example:
 
 .. code-block:: python
 
-   from typing import Union
-
    class Cat:
        def sleep(self) -> None: ...
        def miaow(self) -> None: ...
@@ -69,10 +67,10 @@ Example:
        def sleep(self) -> None: ...
        def follow_me(self) -> None: ...
 
-   def func(animal: Union[Cat, Dog]) -> None:
+   def func(animal: Cat | Dog) -> None:
        # OK: 'sleep' is defined for both Cat and Dog
        animal.sleep()
-       # Error: Item "Cat" of "Union[Cat, Dog]" has no attribute "follow_me"  [union-attr]
+       # Error: Item "Cat" of "Cat | Dog" has no attribute "follow_me"  [union-attr]
        animal.follow_me()
 
 You can often work around these errors by using ``assert isinstance(obj, ClassName)``
@@ -124,8 +122,6 @@ Example:
 
 .. code-block:: python
 
-    from typing import Sequence
-
     def greet(name: str) -> None:
          print('hello', name)
 
@@ -144,9 +140,7 @@ Example:
 
 .. code-block:: python
 
-    from typing import Optional
-
-    def first(x: list[int]) -> Optional[int]:
+    def first(x: list[int]) -> int:
         return x[0] if x else 0
 
     t = (5, 4)
@@ -167,7 +161,7 @@ Example:
 
 .. code-block:: python
 
-   from typing import overload, Optional
+   from typing import overload
 
    @overload
    def inc_maybe(x: None) -> None: ...
@@ -175,7 +169,7 @@ Example:
    @overload
    def inc_maybe(x: int) -> int: ...
 
-   def inc_maybe(x: Optional[int]) -> Optional[int]:
+   def inc_maybe(x: int | None) -> int | None:
         if x is None:
             return None
         else:
@@ -210,11 +204,11 @@ This example incorrectly uses the function ``log`` as a type:
         for x in objs:
             f(x)
 
-You can use :py:data:`~typing.Callable` as the type for callable objects:
+You can use :py:class:`~collections.abc.Callable` as the type for callable objects:
 
 .. code-block:: python
 
-    from typing import Callable
+    from collections.abc import Callable
 
     # OK
     def log_all(objs: list[object], f: Callable[[object], None]) -> None:
@@ -275,16 +269,14 @@ Example:
 
 .. code-block:: python
 
-   from typing import Optional, Union
-
    class Base:
        def method(self,
-                  arg: int) -> Optional[int]:
+                  arg: int) -> int | None:
            ...
 
    class Derived(Base):
        def method(self,
-                  arg: Union[int, str]) -> int:  # OK
+                  arg: int | str) -> int:  # OK
            ...
 
    class DerivedBad(Base):
@@ -434,15 +426,11 @@ Check type variable values [type-var]
 Mypy checks that value of a type variable is compatible with a value
 restriction or the upper bound type.
 
-Example:
+Example (Python 3.12 syntax):
 
 .. code-block:: python
 
-    from typing import TypeVar
-
-    T1 = TypeVar('T1', int, float)
-
-    def add(x: T1, y: T1) -> T1:
+    def add[T1: (int, float)](x: T1, y: T1) -> T1:
         return x + y
 
     add(4, 5.5)  # OK
@@ -783,27 +771,25 @@ Example:
 Safe handling of abstract type object types [type-abstract]
 -----------------------------------------------------------
 
-Mypy always allows instantiating (calling) type objects typed as ``Type[t]``,
+Mypy always allows instantiating (calling) type objects typed as ``type[t]``,
 even if it is not known that ``t`` is non-abstract, since it is a common
 pattern to create functions that act as object factories (custom constructors).
 Therefore, to prevent issues described in the above section, when an abstract
-type object is passed where ``Type[t]`` is expected, mypy will give an error.
-Example:
+type object is passed where ``type[t]`` is expected, mypy will give an error.
+Example (Python 3.12 syntax):
 
 .. code-block:: python
 
    from abc import ABCMeta, abstractmethod
-   from typing import List, Type, TypeVar
 
    class Config(metaclass=ABCMeta):
        @abstractmethod
        def get_value(self, attr: str) -> str: ...
 
-   T = TypeVar("T")
-   def make_many(typ: Type[T], n: int) -> List[T]:
+   def make_many[T](typ: type[T], n: int) -> list[T]:
        return [typ() for _ in range(n)]  # This will raise if typ is abstract
 
-   # Error: Only concrete class can be given where "Type[Config]" is expected [type-abstract]
+   # Error: Only concrete class can be given where "type[Config]" is expected [type-abstract]
    make_many(Config, 5)
 
 .. _code-safe-super:
@@ -1149,6 +1135,34 @@ types you expect.
 
 See :ref:`overloading <function-overloading>` for more explanation.
 
+
+.. _code-overload-cannot-match:
+
+Check for overload signatures that cannot match [overload-cannot-match]
+--------------------------------------------------------------------------
+
+Warn if an ``@overload`` variant can never be matched, because an earlier
+overload has a wider signature. For example, this can happen if the two
+overloads accept the same parameters and each parameter on the first overload
+has the same type or a wider type than the corresponding parameter on the second
+overload.
+
+Example:
+
+.. code-block:: python
+
+    from typing import overload, Union
+
+    @overload
+    def process(response1: object, response2: object) -> object:
+        ...
+    @overload
+    def process(response1: int, response2: int) -> int: # E: Overloaded function signature 2 will never be matched: signature 1's parameter type(s) are the same or broader  [overload-cannot-match]
+        ...
+
+    def process(response1: object, response2: object) -> object:
+        return response1 + response2
+
 .. _code-annotation-unchecked:
 
 Notify about an annotation in an unchecked function [annotation-unchecked]
diff --git a/docs/source/error_code_list2.rst b/docs/source/error_code_list2.rst
index 0655ef2d35d8..6d50e217a77d 100644
--- a/docs/source/error_code_list2.rst
+++ b/docs/source/error_code_list2.rst
@@ -270,7 +270,7 @@ example:
 
     # mypy: enable-error-code="possibly-undefined"
 
-    from typing import Iterable
+    from collections.abc import Iterable
 
     def test(values: Iterable[int], flag: bool) -> None:
         if flag:
@@ -318,7 +318,7 @@ Example:
 
 .. code-block:: python
 
-    from typing import Iterable
+    from collections.abc import Iterable
 
     def transform(items: Iterable[int]) -> list[int]:
         # Error: "items" has type "Iterable[int]" which can always be true in boolean context. Consider using "Collection[int]" instead.  [truthy-iterable]
diff --git a/docs/source/faq.rst b/docs/source/faq.rst
index 195805382cd3..b7f5e3759a7e 100644
--- a/docs/source/faq.rst
+++ b/docs/source/faq.rst
@@ -102,8 +102,8 @@ Structural subtyping can be thought of as "static duck typing".
 Some argue that structural subtyping is better suited for languages with duck
 typing such as Python. Mypy however primarily uses nominal subtyping,
 leaving structural subtyping mostly opt-in (except for built-in protocols
-such as :py:class:`~typing.Iterable` that always support structural subtyping). Here are some
-reasons why:
+such as :py:class:`~collections.abc.Iterable` that always support structural
+subtyping). Here are some reasons why:
 
 1. It is easy to generate short and informative error messages when
    using a nominal type system. This is especially important when
@@ -140,13 +140,14 @@ How are mypy programs different from normal Python?
 Since you use a vanilla Python implementation to run mypy programs,
 mypy programs are also Python programs. The type checker may give
 warnings for some valid Python code, but the code is still always
-runnable. Also, some Python features and syntax are still not
+runnable. Also, a few Python features are still not
 supported by mypy, but this is gradually improving.
 
 The obvious difference is the availability of static type
 checking. The section :ref:`common_issues` mentions some
 modifications to Python code that may be required to make code type
-check without errors. Also, your code must make attributes explicit.
+check without errors. Also, your code must make defined
+attributes explicit.
 
 Mypy supports modular, efficient type checking, and this seems to
 rule out type checking some language features, such as arbitrary
diff --git a/docs/source/final_attrs.rst b/docs/source/final_attrs.rst
index 297b97eca787..81bfba650430 100644
--- a/docs/source/final_attrs.rst
+++ b/docs/source/final_attrs.rst
@@ -25,8 +25,8 @@ Final names
 
 You can use the ``typing.Final`` qualifier to indicate that
 a name or attribute should not be reassigned, redefined, or
-overridden.  This is often useful for module and class level constants
-as a way to prevent unintended modification.  Mypy will prevent
+overridden. This is often useful for module and class-level
+constants to prevent unintended modification. Mypy will prevent
 further assignments to final names in type-checked code:
 
 .. code-block:: python
@@ -70,7 +70,7 @@ You can use ``Final`` in one of these forms:
 
      ID: Final[int] = 1
 
-  Here mypy will infer type ``int`` for ``ID``.
+  Here, mypy will infer type ``int`` for ``ID``.
 
 * You can omit the type:
 
@@ -78,15 +78,15 @@ You can use ``Final`` in one of these forms:
 
      ID: Final = 1
 
-  Here mypy will infer type ``Literal[1]`` for ``ID``. Note that unlike for
-  generic classes this is *not* the same as ``Final[Any]``.
+  Here, mypy will infer type ``Literal[1]`` for ``ID``. Note that unlike for
+  generic classes, this is *not* the same as ``Final[Any]``.
 
-* In class bodies and stub files you can omit the right hand side and just write
+* In class bodies and stub files, you can omit the right-hand side and just write
   ``ID: Final[int]``.
 
 * Finally, you can write ``self.id: Final = 1`` (also optionally with
   a type in square brackets). This is allowed *only* in
-  :py:meth:`__init__ <object.__init__>` methods, so that the final instance attribute is
+  :py:meth:`__init__ <object.__init__>` methods so the final instance attribute is
   assigned only once when an instance is created.
 
 Details of using ``Final``
@@ -129,7 +129,7 @@ the scope of a final declaration automatically depending on whether it was
 initialized in the class body or in :py:meth:`__init__ <object.__init__>`.
 
 A final attribute can't be overridden by a subclass (even with another
-explicit final declaration). Note however that a final attribute can
+explicit final declaration). Note, however, that a final attribute can
 override a read-only property:
 
 .. code-block:: python
@@ -176,12 +176,12 @@ overriding. You can use the ``typing.final`` decorator for this purpose:
 This ``@final`` decorator can be used with instance methods, class methods,
 static methods, and properties.
 
-For overloaded methods you should add ``@final`` on the implementation
+For overloaded methods, you should add ``@final`` on the implementation
 to make it final (or on the first overload in stubs):
 
 .. code-block:: python
 
-   from typing import Any, overload
+   from typing import final, overload
 
    class Base:
        @overload
@@ -224,7 +224,7 @@ Here are some situations where using a final class may be useful:
 
 An abstract class that defines at least one abstract method or
 property and has ``@final`` decorator will generate an error from
-mypy, since those attributes could never be implemented.
+mypy since those attributes could never be implemented.
 
 .. code-block:: python
 
diff --git a/docs/source/generics.rst b/docs/source/generics.rst
index 01ae7534ba93..9c0a308ee39a 100644
--- a/docs/source/generics.rst
+++ b/docs/source/generics.rst
@@ -2,7 +2,7 @@ Generics
 ========
 
 This section explains how you can define your own generic classes that take
-one or more type parameters, similar to built-in types such as ``list[X]``.
+one or more type arguments, similar to built-in types such as ``list[T]``.
 User-defined generics are a moderately advanced feature and you can get far
 without ever using them -- feel free to skip this section and come back later.
 
@@ -12,18 +12,48 @@ Defining generic classes
 ************************
 
 The built-in collection classes are generic classes. Generic types
-have one or more type parameters, which can be arbitrary types. For
-example, ``dict[int, str]`` has the type parameters ``int`` and
-``str``, and ``list[int]`` has a type parameter ``int``.
+accept one or more type arguments within ``[...]``, which can be
+arbitrary types. For example, the type ``dict[int, str]`` has the
+type arguments ``int`` and ``str``, and ``list[int]`` has the type
+argument ``int``.
 
 Programs can also define new generic classes. Here is a very simple
-generic class that represents a stack:
+generic class that represents a stack (using the syntax introduced in
+Python 3.12):
+
+.. code-block:: python
+
+   class Stack[T]:
+       def __init__(self) -> None:
+           # Create an empty list with items of type T
+           self.items: list[T] = []
+
+       def push(self, item: T) -> None:
+           self.items.append(item)
+
+       def pop(self) -> T:
+           return self.items.pop()
+
+       def empty(self) -> bool:
+           return not self.items
+
+There are two syntax variants for defining generic classes in Python.
+Python 3.12 introduced a
+`new dedicated syntax <https://docs.python.org/3/whatsnew/3.12.html#pep-695-type-parameter-syntax>`_
+for defining generic classes (and also functions and type aliases, which
+we will discuss later). The above example used the new syntax. Most examples are
+given using both the new and the old (or legacy) syntax variants.
+Unless mentioned otherwise, they work the same -- but the new syntax
+is more readable and more convenient.
+
+Here is the same example using the old syntax (required for Python 3.11
+and earlier, but also supported on newer Python versions):
 
 .. code-block:: python
 
    from typing import TypeVar, Generic
 
-   T = TypeVar('T')
+   T = TypeVar('T')  # Define type variable "T"
 
    class Stack(Generic[T]):
        def __init__(self) -> None:
@@ -39,8 +69,16 @@ generic class that represents a stack:
        def empty(self) -> bool:
            return not self.items
 
+.. note::
+
+    There are currently no plans to deprecate the legacy syntax.
+    You can freely mix code using the new and old syntax variants,
+    even within a single file (but *not* within a single class).
+
 The ``Stack`` class can be used to represent a stack of any type:
-``Stack[int]``, ``Stack[tuple[int, str]]``, etc.
+``Stack[int]``, ``Stack[tuple[int, str]]``, etc. You can think of
+``Stack[int]`` as referring to the definition of ``Stack`` above,
+but with all instances of ``T`` replaced with ``int``.
 
 Using ``Stack`` is similar to built-in container types:
 
@@ -50,19 +88,49 @@ Using ``Stack`` is similar to built-in container types:
    stack = Stack[int]()
    stack.push(2)
    stack.pop()
-   stack.push('x')  # error: Argument 1 to "push" of "Stack" has incompatible type "str"; expected "int"
 
-Construction of instances of generic types is type checked:
+   # error: Argument 1 to "push" of "Stack" has incompatible type "str"; expected "int"
+   stack.push('x')
+
+   stack2: Stack[str] = Stack()
+   stack2.append('x')
+
+Construction of instances of generic types is type checked (Python 3.12 syntax):
 
 .. code-block:: python
 
-   class Box(Generic[T]):
+   class Box[T]:
        def __init__(self, content: T) -> None:
            self.content = content
 
    Box(1)       # OK, inferred type is Box[int]
    Box[int](1)  # Also OK
-   Box[int]('some string')  # error: Argument 1 to "Box" has incompatible type "str"; expected "int"
+
+   # error: Argument 1 to "Box" has incompatible type "str"; expected "int"
+   Box[int]('some string')
+
+Here is the definition of ``Box`` using the legacy syntax (Python 3.11 and earlier):
+
+.. code-block:: python
+
+   from typing import TypeVar, Generic
+
+   T = TypeVar('T')
+
+   class Box(Generic[T]):
+       def __init__(self, content: T) -> None:
+           self.content = content
+
+.. note::
+
+    Before moving on, let's clarify some terminology.
+    The name ``T`` in ``class Stack[T]`` or ``class Stack(Generic[T])``
+    declares a *type parameter* ``T`` (of class ``Stack``).
+    ``T`` is also called a *type variable*, especially in a type annotation,
+    such as in the signature of ``push`` above.
+    When the type ``Stack[...]`` is used in a type annotation, the type
+    within square brackets is called a *type argument*.
+    This is similar to the distinction between function parameters and arguments.
 
 .. _generic-subclasses:
 
@@ -70,7 +138,37 @@ Defining subclasses of generic classes
 **************************************
 
 User-defined generic classes and generic classes defined in :py:mod:`typing`
-can be used as a base class for another class (generic or non-generic). For example:
+can be used as a base class for another class (generic or non-generic). For
+example (Python 3.12 syntax):
+
+.. code-block:: python
+
+   from typing import Mapping, Iterator
+
+   # This is a generic subclass of Mapping
+   class MyMapp[KT, VT](Mapping[KT, VT]):
+       def __getitem__(self, k: KT) -> VT: ...
+       def __iter__(self) -> Iterator[KT]: ...
+       def __len__(self) -> int: ...
+
+   items: MyMap[str, int]  # OK
+
+   # This is a non-generic subclass of dict
+   class StrDict(dict[str, str]):
+       def __str__(self) -> str:
+           return f'StrDict({super().__str__()})'
+
+   data: StrDict[int, int]  # Error! StrDict is not generic
+   data2: StrDict  # OK
+
+   # This is a user-defined generic class
+   class Receiver[T]:
+       def accept(self, value: T) -> None: ...
+
+   # This is a generic subclass of Receiver
+   class AdvancedReceiver[T](Receiver[T]): ...
+
+Here is the above example using the legacy syntax (Python 3.11 and earlier):
 
 .. code-block:: python
 
@@ -92,7 +190,6 @@ can be used as a base class for another class (generic or non-generic). For exam
        def __str__(self) -> str:
            return f'StrDict({super().__str__()})'
 
-
    data: StrDict[int, int]  # Error! StrDict is not generic
    data2: StrDict  # OK
 
@@ -105,25 +202,27 @@ can be used as a base class for another class (generic or non-generic). For exam
 
 .. note::
 
-    You have to add an explicit :py:class:`~typing.Mapping` base class
+    You have to add an explicit :py:class:`~collections.abc.Mapping` base class
     if you want mypy to consider a user-defined class as a mapping (and
-    :py:class:`~typing.Sequence` for sequences, etc.). This is because mypy doesn't use
-    *structural subtyping* for these ABCs, unlike simpler protocols
-    like :py:class:`~typing.Iterable`, which use :ref:`structural subtyping <protocol-types>`.
+    :py:class:`~collections.abc.Sequence` for sequences, etc.). This is because
+    mypy doesn't use *structural subtyping* for these ABCs, unlike simpler protocols
+    like :py:class:`~collections.abc.Iterable`, which use
+    :ref:`structural subtyping <protocol-types>`.
 
-:py:class:`Generic <typing.Generic>` can be omitted from bases if there are
+When using the legacy syntax, :py:class:`Generic <typing.Generic>` can be omitted
+from bases if there are
 other base classes that include type variables, such as ``Mapping[KT, VT]``
 in the above example. If you include ``Generic[...]`` in bases, then
 it should list all type variables present in other bases (or more,
-if needed). The order of type variables is defined by the following
+if needed). The order of type parameters is defined by the following
 rules:
 
-* If ``Generic[...]`` is present, then the order of variables is
+* If ``Generic[...]`` is present, then the order of parameters is
   always determined by their order in ``Generic[...]``.
-* If there are no ``Generic[...]`` in bases, then all type variables
+* If there are no ``Generic[...]`` in bases, then all type parameters
   are collected in the lexicographic order (i.e. by first appearance).
 
-For example:
+Example:
 
 .. code-block:: python
 
@@ -142,12 +241,26 @@ For example:
    x: First[int, str]        # Here T is bound to int, S is bound to str
    y: Second[int, str, Any]  # Here T is Any, S is int, and U is str
 
+When using the Python 3.12 syntax, all type parameters must always be
+explicitly defined immediately after the class name within ``[...]``, and the
+``Generic[...]`` base class is never used.
+
 .. _generic-functions:
 
 Generic functions
 *****************
 
-Type variables can be used to define generic functions:
+Functions can also be generic, i.e. they can have type parameters (Python 3.12 syntax):
+
+.. code-block:: python
+
+   from collections.abc import Sequence
+
+   # A generic function!
+   def first[T](seq: Sequence[T]) -> T:
+       return seq[0]
+
+Here is the same example using the legacy syntax (Python 3.11 and earlier):
 
 .. code-block:: python
 
@@ -159,24 +272,25 @@ Type variables can be used to define generic functions:
    def first(seq: Sequence[T]) -> T:
        return seq[0]
 
-As with generic classes, the type variable can be replaced with any
-type. That means ``first`` can be used with any sequence type, and the
-return type is derived from the sequence item type. For example:
+As with generic classes, the type parameter ``T`` can be replaced with any
+type. That means ``first`` can be passed an argument with any sequence type,
+and the return type is derived from the sequence item type. Example:
 
 .. code-block:: python
 
    reveal_type(first([1, 2, 3]))   # Revealed type is "builtins.int"
-   reveal_type(first(['a', 'b']))  # Revealed type is "builtins.str"
+   reveal_type(first(('a', 'b')))  # Revealed type is "builtins.str"
 
-Note also that a single definition of a type variable (such as ``T``
-above) can be used in multiple generic functions or classes. In this
-example we use the same type variable in two generic functions:
+When using the legacy syntax, a single definition of a type variable
+(such as ``T`` above) can be used in multiple generic functions or
+classes. In this example we use the same type variable in two generic
+functions to declarare type parameters:
 
 .. code-block:: python
 
    from typing import TypeVar, Sequence
 
-   T = TypeVar('T')      # Declare type variable
+   T = TypeVar('T')      # Define type variable
 
    def first(seq: Sequence[T]) -> T:
        return seq[0]
@@ -184,20 +298,109 @@ example we use the same type variable in two generic functions:
    def last(seq: Sequence[T]) -> T:
        return seq[-1]
 
+Since the Python 3.12 syntax is more concise, it doesn't need (or have)
+an equivalent way of sharing type parameter definitions.
+
 A variable cannot have a type variable in its type unless the type
 variable is bound in a containing generic class or function.
 
+When calling a generic function, you can't explicitly pass the values of
+type parameters as type arguments. The values of type parameters are always
+inferred by mypy. This is not valid:
+
+.. code-block:: python
+
+    first[int]([1, 2])  # Error: can't use [...] with generic function
+
+If you really need this, you can define a generic class with a ``__call__``
+method.
+
+.. _type-variable-upper-bound:
+
+Type variables with upper bounds
+********************************
+
+A type variable can also be restricted to having values that are
+subtypes of a specific type. This type is called the upper bound of
+the type variable, and it is specified using ``T: <bound>`` when using the
+Python 3.12 syntax. In the definition of a generic function or a generic
+class that uses such a type variable ``T``, the type represented by ``T``
+is assumed to be a subtype of its upper bound, so you can use methods
+of the upper bound on values of type ``T`` (Python 3.12 syntax):
+
+.. code-block:: python
+
+   from typing import SupportsAbs
+
+   def max_by_abs[T: SupportsAbs[float]](*xs: T) -> T:
+       # We can use abs(), because T is a subtype of SupportsAbs[float].
+       return max(xs, key=abs)
+
+An upper bound can also be specified with the ``bound=...`` keyword
+argument to :py:class:`~typing.TypeVar`.
+Here is the example using the legacy syntax (Python 3.11 and earlier):
+
+.. code-block:: python
+
+   from typing import TypeVar, SupportsAbs
+
+   T = TypeVar('T', bound=SupportsAbs[float])
+
+   def max_by_abs(*xs: T) -> T:
+       return max(xs, key=abs)
+
+In a call to such a function, the type ``T`` must be replaced by a
+type that is a subtype of its upper bound. Continuing the example
+above:
+
+.. code-block:: python
+
+   max_by_abs(-3.5, 2)   # Okay, has type 'float'
+   max_by_abs(5+6j, 7)   # Okay, has type 'complex'
+   max_by_abs('a', 'b')  # Error: 'str' is not a subtype of SupportsAbs[float]
+
+Type parameters of generic classes may also have upper bounds, which
+restrict the valid values for the type parameter in the same way.
+
 .. _generic-methods-and-generic-self:
 
 Generic methods and generic self
 ********************************
 
-You can also define generic methods — just use a type variable in the
-method signature that is different from class type variables. In
-particular, the ``self`` argument may also be generic, allowing a
+You can also define generic methods. In
+particular, the ``self`` parameter may also be generic, allowing a
 method to return the most precise type known at the point of access.
 In this way, for example, you can type check a chain of setter
-methods:
+methods (Python 3.12 syntax):
+
+.. code-block:: python
+
+   class Shape:
+       def set_scale[T: Shape](self: T, scale: float) -> T:
+           self.scale = scale
+           return self
+
+   class Circle(Shape):
+       def set_radius(self, r: float) -> 'Circle':
+           self.radius = r
+           return self
+
+   class Square(Shape):
+       def set_width(self, w: float) -> 'Square':
+           self.width = w
+           return self
+
+   circle: Circle = Circle().set_scale(0.5).set_radius(2.7)
+   square: Square = Square().set_scale(0.5).set_width(3.2)
+
+Without using generic ``self``, the last two lines could not be type
+checked properly, since the return type of ``set_scale`` would be
+``Shape``, which doesn't define ``set_radius`` or ``set_width``.
+
+When using the legacy syntax, just use a type variable in the
+method signature that is different from class type parameters (if any
+are defined). Here is the above example using the legacy
+syntax (3.11 and earlier):
 
 .. code-block:: python
 
@@ -223,24 +426,40 @@ methods:
    circle: Circle = Circle().set_scale(0.5).set_radius(2.7)
    square: Square = Square().set_scale(0.5).set_width(3.2)
 
-Without using generic ``self``, the last two lines could not be type
-checked properly, since the return type of ``set_scale`` would be
-``Shape``, which doesn't define ``set_radius`` or ``set_width``.
+Other uses include factory methods, such as copy and deserialization methods.
+For class methods, you can also define generic ``cls``, using ``type[T]``
+or :py:class:`Type[T] <typing.Type>` (Python 3.12 syntax):
+
+.. code-block:: python
 
-Other uses are factory methods, such as copy and deserialization.
-For class methods, you can also define generic ``cls``, using :py:class:`Type[T] <typing.Type>`:
+   class Friend:
+       other: "Friend | None" = None
+
+       @classmethod
+       def make_pair[T: Friend](cls: type[T]) -> tuple[T, T]:
+           a, b = cls(), cls()
+           a.other = b
+           b.other = a
+           return a, b
+
+   class SuperFriend(Friend):
+       pass
+
+   a, b = SuperFriend.make_pair()
+
+Here is the same example using the legacy syntax (3.11 and earlier):
 
 .. code-block:: python
 
-   from typing import TypeVar, Type
+   from typing import TypeVar
 
    T = TypeVar('T', bound='Friend')
 
    class Friend:
-       other: "Friend" = None
+       other: "Friend | None" = None
 
        @classmethod
-       def make_pair(cls: Type[T]) -> tuple[T, T]:
+       def make_pair(cls: type[T]) -> tuple[T, T]:
            a, b = cls(), cls()
            a.other = b
            b.other = a
@@ -260,18 +479,15 @@ or a deserialization method returns the actual type of self. Therefore
 you may need to silence mypy inside these methods (but not at the call site),
 possibly by making use of the ``Any`` type or a ``# type: ignore`` comment.
 
-Note that mypy lets you use generic self types in certain unsafe ways
+Mypy lets you use generic self types in certain unsafe ways
 in order to support common idioms. For example, using a generic
-self type in an argument type is accepted even though it's unsafe:
+self type in an argument type is accepted even though it's unsafe (Python 3.12
+syntax):
 
 .. code-block:: python
 
-   from typing import TypeVar
-
-   T = TypeVar("T")
-
    class Base:
-       def compare(self: T, other: T) -> bool:
+       def compare[T: Base](self: T, other: T) -> bool:
            return False
 
    class Sub(Base):
@@ -280,7 +496,7 @@ self type in an argument type is accepted even though it's unsafe:
 
        # This is unsafe (see below) but allowed because it's
        # a common pattern and rarely causes issues in practice.
-       def compare(self, other: Sub) -> bool:
+       def compare(self, other: 'Sub') -> bool:
            return self.x > other.x
 
    b: Base = Sub(42)
@@ -293,12 +509,12 @@ Automatic self types using typing.Self
 
 Since the patterns described above are quite common, mypy supports a
 simpler syntax, introduced in :pep:`673`, to make them easier to use.
-Instead of defining a type variable and using an explicit annotation
+Instead of introducing a type parameter and using an explicit annotation
 for ``self``, you can import the special type ``typing.Self`` that is
-automatically transformed into a type variable with the current class
-as the upper bound, and you don't need an annotation for ``self`` (or
-``cls`` in class methods). The example from the previous section can
-be made simpler by using ``Self``:
+automatically transformed into a method-level type parameter with the
+current class as the upper bound, and you don't need an annotation for
+``self`` (or ``cls`` in class methods). The example from the previous
+section can be made simpler by using ``Self``:
 
 .. code-block:: python
 
@@ -319,7 +535,7 @@ be made simpler by using ``Self``:
 
    a, b = SuperFriend.make_pair()
 
-This is more compact than using explicit type variables. Also, you can
+This is more compact than using explicit type parameters. Also, you can
 use ``Self`` in attribute annotations in addition to methods.
 
 .. note::
@@ -354,10 +570,10 @@ Let us illustrate this by few simple examples:
     class Triangle(Shape): ...
     class Square(Shape): ...
 
-* Most immutable containers, such as :py:class:`~typing.Sequence` and
-  :py:class:`~typing.FrozenSet` are covariant. :py:data:`~typing.Union` is
-  also covariant in all variables: ``Union[Triangle, int]`` is
-  a subtype of ``Union[Shape, int]``.
+* Most immutable container types, such as :py:class:`~collections.abc.Sequence`
+  and :py:class:`~frozenset` are covariant. Union types are
+  also covariant in all union items: ``Triangle | int`` is
+  a subtype of ``Shape | int``.
 
   .. code-block:: python
 
@@ -367,7 +583,7 @@ Let us illustrate this by few simple examples:
     triangles: Sequence[Triangle]
     count_lines(triangles)  # OK
 
-    def foo(triangle: Triangle, num: int):
+    def foo(triangle: Triangle, num: int) -> None:
         shape_or_number: Union[Shape, int]
         # a Triangle is a Shape, and a Shape is a valid Union[Shape, int]
         shape_or_number = triangle
@@ -375,7 +591,7 @@ Let us illustrate this by few simple examples:
   Covariance should feel relatively intuitive, but contravariance and invariance
   can be harder to reason about.
 
-* :py:data:`~typing.Callable` is an example of type that behaves contravariant
+* :py:class:`~collections.abc.Callable` is an example of type that behaves contravariant
   in types of arguments. That is, ``Callable[[Shape], int]`` is a subtype of
   ``Callable[[Triangle], int]``, despite ``Shape`` being a supertype of
   ``Triangle``. To understand this, consider:
@@ -400,8 +616,8 @@ Let us illustrate this by few simple examples:
   triangle. If we give it a callable that can calculate the area of an
   arbitrary shape (not just triangles), everything still works.
 
-* :py:class:`~typing.List` is an invariant generic type. Naively, one would think
-  that it is covariant, like :py:class:`~typing.Sequence` above, but consider this code:
+* ``list`` is an invariant generic type. Naively, one would think
+  that it is covariant, like :py:class:`~collections.abc.Sequence` above, but consider this code:
 
   .. code-block:: python
 
@@ -416,107 +632,104 @@ Let us illustrate this by few simple examples:
      add_one(my_circles)     # This may appear safe, but...
      my_circles[-1].rotate()  # ...this will fail, since my_circles[0] is now a Shape, not a Circle
 
-  Another example of invariant type is :py:class:`~typing.Dict`. Most mutable containers
+  Another example of invariant type is ``dict``. Most mutable containers
   are invariant.
 
-By default, mypy assumes that all user-defined generics are invariant.
-To declare a given generic class as covariant or contravariant use
-type variables defined with special keyword arguments ``covariant`` or
-``contravariant``. For example:
+When using the Python 3.12 syntax for generics, mypy will automatically
+infer the most flexible variance for each class type variable. Here
+``Box`` will be inferred as covariant:
 
 .. code-block:: python
 
-   from typing import Generic, TypeVar
-
-   T_co = TypeVar('T_co', covariant=True)
-
-   class Box(Generic[T_co]):  # this type is declared covariant
-       def __init__(self, content: T_co) -> None:
+   class Box[T]:  # this type is implilicitly covariant
+       def __init__(self, content: T) -> None:
            self._content = content
 
-       def get_content(self) -> T_co:
+       def get_content(self) -> T:
            return self._content
 
-   def look_into(box: Box[Animal]): ...
+   def look_into(box: Box[Shape]): ...
 
-   my_box = Box(Cat())
+   my_box = Box(Square())
    look_into(my_box)  # OK, but mypy would complain here for an invariant type
 
-.. _type-variable-upper-bound:
-
-Type variables with upper bounds
-********************************
-
-A type variable can also be restricted to having values that are
-subtypes of a specific type. This type is called the upper bound of
-the type variable, and is specified with the ``bound=...`` keyword
-argument to :py:class:`~typing.TypeVar`.
+Here the underscore prefix for ``_content`` is significant. Without an
+underscore prefix, the class would be invariant, as the attribute would
+be understood as a public, mutable attribute (a single underscore prefix
+has no special significance for mypy in most other contexts). By declaring
+the attribute as ``Final``, the class could still be made covariant:
 
 .. code-block:: python
 
-   from typing import TypeVar, SupportsAbs
+   from typing import Final
 
-   T = TypeVar('T', bound=SupportsAbs[float])
+   class Box[T]:  # this type is implilicitly covariant
+       def __init__(self, content: T) -> None:
+           self.content: Final = content
 
-In the definition of a generic function that uses such a type variable
-``T``, the type represented by ``T`` is assumed to be a subtype of
-its upper bound, so the function can use methods of the upper bound on
-values of type ``T``.
+       def get_content(self) -> T:
+           return self._content
+
+When using the legacy syntax, mypy assumes that all user-defined generics
+are invariant by default. To declare a given generic class as covariant or
+contravariant, use type variables defined with special keyword arguments
+``covariant`` or ``contravariant``. For example (Python 3.11 or earlier):
 
 .. code-block:: python
 
-   def largest_in_absolute_value(*xs: T) -> T:
-       return max(xs, key=abs)  # Okay, because T is a subtype of SupportsAbs[float].
+   from typing import Generic, TypeVar
 
-In a call to such a function, the type ``T`` must be replaced by a
-type that is a subtype of its upper bound. Continuing the example
-above:
+   T_co = TypeVar('T_co', covariant=True)
 
-.. code-block:: python
+   class Box(Generic[T_co]):  # this type is declared covariant
+       def __init__(self, content: T_co) -> None:
+           self._content = content
 
-   largest_in_absolute_value(-3.5, 2)   # Okay, has type float.
-   largest_in_absolute_value(5+6j, 7)   # Okay, has type complex.
-   largest_in_absolute_value('a', 'b')  # Error: 'str' is not a subtype of SupportsAbs[float].
+       def get_content(self) -> T_co:
+           return self._content
 
-Type parameters of generic classes may also have upper bounds, which
-restrict the valid values for the type parameter in the same way.
+   def look_into(box: Box[Shape]): ...
+
+   my_box = Box(Square())
+   look_into(my_box)  # OK, but mypy would complain here for an invariant type
 
 .. _type-variable-value-restriction:
 
 Type variables with value restriction
 *************************************
 
-By default, a type variable can be replaced with any type. However, sometimes
+By default, a type variable can be replaced with any type -- or any type that
+is a subtype of the upper bound, which defaults to ``object``. However, sometimes
 it's useful to have a type variable that can only have some specific types
 as its value. A typical example is a type variable that can only have values
-``str`` and ``bytes``:
+``str`` and ``bytes``. This lets us define a function that can concatenate
+two strings or bytes objects, but it can't be called with other argument
+types (Python 3.12 syntax):
 
 .. code-block:: python
 
-   from typing import TypeVar
+   def concat[S: (str, bytes)](x: S, y: S) -> S:
+       return x + y
 
-   AnyStr = TypeVar('AnyStr', str, bytes)
+   concat('a', 'b')    # Okay
+   concat(b'a', b'b')  # Okay
+   concat(1, 2)        # Error!
 
-This is actually such a common type variable that :py:data:`~typing.AnyStr` is
-defined in :py:mod:`typing` and we don't need to define it ourselves.
 
-We can use :py:data:`~typing.AnyStr` to define a function that can concatenate
-two strings or bytes objects, but it can't be called with other
-argument types:
+The same thing is also possibly using the legacy syntax (Python 3.11 or earlier):
 
 .. code-block:: python
 
-   from typing import AnyStr
+   from typing import TypeVar
+
+   AnyStr = TypeVar('AnyStr', str, bytes)
 
    def concat(x: AnyStr, y: AnyStr) -> AnyStr:
        return x + y
 
-   concat('a', 'b')    # Okay
-   concat(b'a', b'b')  # Okay
-   concat(1, 2)        # Error!
-
-Importantly, this is different from a union type, since combinations
-of ``str`` and ``bytes`` are not accepted:
+No matter which syntax you use, such a type variable is called a type variable
+with a value restriction. Importantly, this is different from a union type,
+since combinations of ``str`` and ``bytes`` are not accepted:
 
 .. code-block:: python
 
@@ -524,11 +737,11 @@ of ``str`` and ``bytes`` are not accepted:
 
 In this case, this is exactly what we want, since it's not possible
 to concatenate a string and a bytes object! If we tried to use
-``Union``, the type checker would complain about this possibility:
+a union type, the type checker would complain about this possibility:
 
 .. code-block:: python
 
-   def union_concat(x: Union[str, bytes], y: Union[str, bytes]) -> Union[str, bytes]:
+   def union_concat(x: str | bytes, y: str | bytes) -> str | bytes:
        return x + y  # Error: can't concatenate str and bytes
 
 Another interesting special case is calling ``concat()`` with a
@@ -545,24 +758,28 @@ You may expect that the type of ``ss`` is ``S``, but the type is
 actually ``str``: a subtype gets promoted to one of the valid values
 for the type variable, which in this case is ``str``.
 
-This is thus
-subtly different from *bounded quantification* in languages such as
-Java, where the return type would be ``S``. The way mypy implements
-this is correct for ``concat``, since ``concat`` actually returns a
-``str`` instance in the above example:
+This is thus subtly different from using ``str | bytes`` as an upper bound,
+where the return type would be ``S`` (see :ref:`type-variable-upper-bound`).
+Using a value restriction is correct for ``concat``, since ``concat``
+actually returns a ``str`` instance in the above example:
 
 .. code-block:: python
 
     >>> print(type(ss))
     <class 'str'>
 
-You can also use a :py:class:`~typing.TypeVar` with a restricted set of possible
-values when defining a generic class. For example, mypy uses the type
-:py:class:`Pattern[AnyStr] <typing.Pattern>` for the return value of :py:func:`re.compile`,
-since regular expressions can be based on a string or a bytes pattern.
+You can also use type variables with a restricted set of possible
+values when defining a generic class. For example, the type
+:py:class:`Pattern[S] <typing.Pattern>` is used for the return
+value of :py:func:`re.compile`, where ``S`` can be either ``str``
+or ``bytes``. Regular expressions can be based on a string or a
+bytes pattern.
+
+A type variable may not have both a value restriction and an upper bound.
 
-A type variable may not have both a value restriction (see
-:ref:`type-variable-upper-bound`) and an upper bound.
+Note that you may come across :py:data:`~typing.AnyStr` imported from
+:py:mod:`typing`. This feature is now deprecated, but it means the same
+as our definition of ``AnyStr`` above.
 
 .. _declaring-decorators:
 
@@ -571,11 +788,12 @@ Declaring decorators
 
 Decorators are typically functions that take a function as an argument and
 return another function. Describing this behaviour in terms of types can
-be a little tricky; we'll show how you can use ``TypeVar`` and a special
+be a little tricky; we'll show how you can use type variables and a special
 kind of type variable called a *parameter specification* to do so.
 
 Suppose we have the following decorator, not type annotated yet,
-that preserves the original function's signature and merely prints the decorated function's name:
+that preserves the original function's signature and merely prints the decorated
+function's name:
 
 .. code-block:: python
 
@@ -585,7 +803,7 @@ that preserves the original function's signature and merely prints the decorated
            return func(*args, **kwds)
        return wrapper
 
-and we use it to decorate function ``add_forty_two``:
+We can use it to decorate function ``add_forty_two``:
 
 .. code-block:: python
 
@@ -611,11 +829,34 @@ Note that class decorators are handled differently than function decorators in
 mypy: decorating a class does not erase its type, even if the decorator has
 incomplete type annotations.
 
-Here's how one could annotate the decorator:
+Here's how one could annotate the decorator (Python 3.12 syntax):
 
 .. code-block:: python
 
-   from typing import Any, Callable, TypeVar, cast
+   from collections.abc import Callable
+   from typing import Any, cast
+
+   # A decorator that preserves the signature.
+   def printing_decorator[F: Callable[..., Any]](func: F) -> F:
+       def wrapper(*args, **kwds):
+           print("Calling", func)
+           return func(*args, **kwds)
+       return cast(F, wrapper)
+
+   @printing_decorator
+   def add_forty_two(value: int) -> int:
+       return value + 42
+
+   a = add_forty_two(3)
+   reveal_type(a)      # Revealed type is "builtins.int"
+   add_forty_two('x')  # Argument 1 to "add_forty_two" has incompatible type "str"; expected "int"
+
+Here is the example using the legacy syntax (Python 3.11 and earlier):
+
+.. code-block:: python
+
+   from collections.abc import Callable
+   from typing import Any, TypeVar, cast
 
    F = TypeVar('F', bound=Callable[..., Any])
 
@@ -636,19 +877,33 @@ Here's how one could annotate the decorator:
 
 This still has some shortcomings. First, we need to use the unsafe
 :py:func:`~typing.cast` to convince mypy that ``wrapper()`` has the same
-signature as ``func``. See :ref:`casts <casts>`.
+signature as ``func`` (see :ref:`casts <casts>`).
 
 Second, the ``wrapper()`` function is not tightly type checked, although
 wrapper functions are typically small enough that this is not a big
 problem. This is also the reason for the :py:func:`~typing.cast` call in the
 ``return`` statement in ``printing_decorator()``.
 
-However, we can use a parameter specification (:py:class:`~typing.ParamSpec`),
-for a more faithful type annotation:
+However, we can use a parameter specification, introduced using ``**P``,
+for a more faithful type annotation (Python 3.12 syntax):
+
+.. code-block:: python
+
+   from collections.abc import Callable
+
+   def printing_decorator[**P, T](func: Callable[P, T]) -> Callable[P, T]:
+       def wrapper(*args: P.args, **kwds: P.kwargs) -> T:
+           print("Calling", func)
+           return func(*args, **kwds)
+       return wrapper
+
+The same is possible using the legacy syntax with :py:class:`~typing.ParamSpec`
+(Python 3.11 and earlier):
 
 .. code-block:: python
 
-   from typing import Callable, TypeVar
+   from collections.abc import Callable
+   from typing import TypeVar
    from typing_extensions import ParamSpec
 
    P = ParamSpec('P')
@@ -661,18 +916,14 @@ for a more faithful type annotation:
        return wrapper
 
 Parameter specifications also allow you to describe decorators that
-alter the signature of the input function:
+alter the signature of the input function (Python 3.12 syntax):
 
 .. code-block:: python
 
-   from typing import Callable, TypeVar
-   from typing_extensions import ParamSpec
-
-   P = ParamSpec('P')
-   T = TypeVar('T')
+   from collections.abc import Callable
 
-    # We reuse 'P' in the return type, but replace 'T' with 'str'
-   def stringify(func: Callable[P, T]) -> Callable[P, str]:
+   # We reuse 'P' in the return type, but replace 'T' with 'str'
+   def stringify[**P, T](func: Callable[P, T]) -> Callable[P, str]:
        def wrapper(*args: P.args, **kwds: P.kwargs) -> str:
            return str(func(*args, **kwds))
        return wrapper
@@ -685,17 +936,31 @@ alter the signature of the input function:
     reveal_type(a)      # Revealed type is "builtins.str"
     add_forty_two('x')  # error: Argument 1 to "add_forty_two" has incompatible type "str"; expected "int"
 
-Or insert an argument:
+Here is the above example using the legacy syntax (Python 3.11 and earlier):
 
 .. code-block:: python
 
-    from typing import Callable, TypeVar
-    from typing_extensions import Concatenate, ParamSpec
+   from collections.abc import Callable
+   from typing import TypeVar
+   from typing_extensions import ParamSpec
 
-    P = ParamSpec('P')
-    T = TypeVar('T')
+   P = ParamSpec('P')
+   T = TypeVar('T')
 
-    def printing_decorator(func: Callable[P, T]) -> Callable[Concatenate[str, P], T]:
+   # We reuse 'P' in the return type, but replace 'T' with 'str'
+   def stringify(func: Callable[P, T]) -> Callable[P, str]:
+       def wrapper(*args: P.args, **kwds: P.kwargs) -> str:
+           return str(func(*args, **kwds))
+       return wrapper
+
+You can also insert an argument in a decorator (Python 3.12 syntax):
+
+.. code-block:: python
+
+    from collections.abc import Callable
+    from typing import Concatenate
+
+    def printing_decorator[**P, T](func: Callable[P, T]) -> Callable[Concatenate[str, P], T]:
         def wrapper(msg: str, /, *args: P.args, **kwds: P.kwargs) -> T:
             print("Calling", func, "with", msg)
             return func(*args, **kwds)
@@ -707,17 +972,54 @@ Or insert an argument:
 
     a = add_forty_two('three', 3)
 
+Here is the same function using the legacy syntax (Python 3.11 and earlier):
+
+.. code-block:: python
+
+    from collections.abc import Callable
+    from typing import TypeVar
+    from typing_extensions import Concatenate, ParamSpec
+
+    P = ParamSpec('P')
+    T = TypeVar('T')
+
+    def printing_decorator(func: Callable[P, T]) -> Callable[Concatenate[str, P], T]:
+        def wrapper(msg: str, /, *args: P.args, **kwds: P.kwargs) -> T:
+            print("Calling", func, "with", msg)
+            return func(*args, **kwds)
+        return wrapper
+
 .. _decorator-factories:
 
 Decorator factories
 -------------------
 
 Functions that take arguments and return a decorator (also called second-order decorators), are
-similarly supported via generics:
+similarly supported via generics (Python 3.12 syntax):
+
+.. code-block:: python
+
+    from colletions.abc import Callable
+    from typing import Any
+
+    def route[F: Callable[..., Any]](url: str) -> Callable[[F], F]:
+        ...
+
+    @route(url='/')
+    def index(request: Any) -> str:
+        return 'Hello world'
+
+Note that mypy infers that ``F`` is used to make the ``Callable`` return value
+of ``route`` generic, instead of making ``route`` itself generic, since ``F`` is
+only used in the return type. Python has no explicit syntax to mark that ``F``
+is only bound in the return value.
+
+Here is the example using the legacy syntax (Python 3.11 and earlier):
 
 .. code-block:: python
 
-    from typing import Any, Callable, TypeVar
+    from collections.abc import Callable
+    from typing import Any, TypeVar
 
     F = TypeVar('F', bound=Callable[..., Any])
 
@@ -729,23 +1031,22 @@ similarly supported via generics:
         return 'Hello world'
 
 Sometimes the same decorator supports both bare calls and calls with arguments. This can be
-achieved by combining with :py:func:`@overload <typing.overload>`:
+achieved by combining with :py:func:`@overload <typing.overload>` (Python 3.12 syntax):
 
 .. code-block:: python
 
-    from typing import Any, Callable, Optional, TypeVar, overload
-
-    F = TypeVar('F', bound=Callable[..., Any])
+    from collections.abc import Callable
+    from typing import Any, overload
 
     # Bare decorator usage
     @overload
-    def atomic(__func: F) -> F: ...
+    def atomic[F: Callable[..., Any]](func: F, /) -> F: ...
     # Decorator with arguments
     @overload
-    def atomic(*, savepoint: bool = True) -> Callable[[F], F]: ...
+    def atomic[F: Callable[..., Any]](*, savepoint: bool = True) -> Callable[[F], F]: ...
 
     # Implementation
-    def atomic(__func: Optional[Callable[..., Any]] = None, *, savepoint: bool = True):
+    def atomic(func: Callable[..., Any] | None = None, /, *, savepoint: bool = True):
         def decorator(func: Callable[..., Any]):
             ...  # Code goes here
         if __func is not None:
@@ -760,21 +1061,41 @@ achieved by combining with :py:func:`@overload <typing.overload>`:
     @atomic(savepoint=False)
     def func2() -> None: ...
 
+Here is the decorator from the example using the legacy syntax
+(Python 3.11 and earlier):
+
+.. code-block:: python
+
+    from collections.abc import Callable
+    from typing import Any, Optional, TypeVar, overload
+
+    F = TypeVar('F', bound=Callable[..., Any])
+
+    # Bare decorator usage
+    @overload
+    def atomic(func: F, /) -> F: ...
+    # Decorator with arguments
+    @overload
+    def atomic(*, savepoint: bool = True) -> Callable[[F], F]: ...
+
+    # Implementation
+    def atomic(func: Optional[Callable[..., Any]] = None, /, *, savepoint: bool = True):
+        ...  # Same as above
+
 Generic protocols
 *****************
 
 Mypy supports generic protocols (see also :ref:`protocol-types`). Several
 :ref:`predefined protocols <predefined_protocols>` are generic, such as
-:py:class:`Iterable[T] <typing.Iterable>`, and you can define additional generic protocols. Generic
-protocols mostly follow the normal rules for generic classes. Example:
+:py:class:`Iterable[T] <collections.abc.Iterable>`, and you can define additional
+generic protocols. Generic protocols mostly follow the normal rules for
+generic classes. Example (Python 3.12 syntax):
 
 .. code-block:: python
 
-   from typing import Protocol, TypeVar
+   from typing import Protocol
 
-   T = TypeVar('T')
-
-   class Box(Protocol[T]):
+   class Box[T](Protocol):
        content: T
 
    def do_stuff(one: Box[str], other: Box[bytes]) -> None:
@@ -794,15 +1115,29 @@ protocols mostly follow the normal rules for generic classes. Example:
    y: Box[int] = ...
    x = y  # Error -- Box is invariant
 
+Here is the definition of ``Box`` from the above example using the legacy
+syntax (Python 3.11 and earlier):
+
+.. code-block:: python
+
+   from typing import Protocol, TypeVar
+
+   T = TypeVar('T')
+
+   class Box(Protocol[T]):
+       content: T
+
 Note that ``class ClassName(Protocol[T])`` is allowed as a shorthand for
-``class ClassName(Protocol, Generic[T])``, as per :pep:`PEP 544: Generic protocols <544#generic-protocols>`,
+``class ClassName(Protocol, Generic[T])`` when using the legacy syntax,
+as per :pep:`PEP 544: Generic protocols <544#generic-protocols>`.
+This form is only valid when using the legacy syntax.
 
-The main difference between generic protocols and ordinary generic
-classes is that mypy checks that the declared variances of generic
-type variables in a protocol match how they are used in the protocol
-definition.  The protocol in this example is rejected, since the type
-variable ``T`` is used covariantly as a return type, but the type
-variable is invariant:
+When using the legacy syntax, there is an important difference between
+generic protocols and ordinary generic classes: mypy checks that the
+declared variances of generic type variables in a protocol match how
+they are used in the protocol definition.  The protocol in this example
+is rejected, since the type variable ``T`` is used covariantly as
+a return type, but the type variable is invariant:
 
 .. code-block:: python
 
@@ -830,13 +1165,11 @@ This example correctly uses a covariant type variable:
 
 See :ref:`variance-of-generics` for more about variance.
 
-Generic protocols can also be recursive. Example:
+Generic protocols can also be recursive. Example (Python 3.12 synta):
 
 .. code-block:: python
 
-   T = TypeVar('T')
-
-   class Linked(Protocol[T]):
+   class Linked[T](Protocol):
        val: T
        def next(self) -> 'Linked[T]': ...
 
@@ -849,17 +1182,63 @@ Generic protocols can also be recursive. Example:
    result = last(L())
    reveal_type(result)  # Revealed type is "builtins.int"
 
+Here is the definition of ``Linked`` using the legacy syntax
+(Python 3.11 and earlier):
+
+.. code-block:: python
+
+   from typing import TypeVar
+
+   T = TypeVar('T')
+
+   class Linked(Protocol[T]):
+       val: T
+       def next(self) -> 'Linked[T]': ...
+
 .. _generic-type-aliases:
 
 Generic type aliases
 ********************
 
-Type aliases can be generic. In this case they can be used in two ways:
-Subscripted aliases are equivalent to original types with substituted type
-variables, so the number of type arguments must match the number of free type variables
-in the generic type alias. Unsubscripted aliases are treated as original types with free
-variables replaced with ``Any``. Examples (following :pep:`PEP 484: Type aliases
-<484#type-aliases>`):
+Type aliases can be generic. In this case they can be used in two ways.
+First, subscripted aliases are equivalent to original types with substituted type
+variables. Second, unsubscripted aliases are treated as original types with type
+parameters replaced with ``Any``.
+
+The ``type`` statement introduced in Python 3.12 is used to define generic
+type aliases (it also supports non-generic type aliases):
+
+.. code-block:: python
+
+    from collections.abc import Callable, Iterable
+
+    type TInt[S] = tuple[int, S]
+    type UInt[S] = S | int
+    type CBack[S] = Callable[..., S]
+
+    def response(query: str) -> UInt[str]:  # Same as str | int
+        ...
+    def activate[S](cb: CBack[S]) -> S:        # Same as Callable[..., S]
+        ...
+    table_entry: TInt  # Same as tuple[int, Any]
+
+    type Vec[T: (int, float, complex)] = Iterable[tuple[T, T]]
+
+    def inproduct[T: (int, float, complex)](v: Vec[T]) -> T:
+        return sum(x*y for x, y in v)
+
+    def dilate[T: (int, float, complex)](v: Vec[T], scale: T) -> Vec[T]:
+        return ((x * scale, y * scale) for x, y in v)
+
+    v1: Vec[int] = []      # Same as Iterable[tuple[int, int]]
+    v2: Vec = []           # Same as Iterable[tuple[Any, Any]]
+    v3: Vec[int, int] = [] # Error: Invalid alias, too many type arguments!
+
+There is also a legacy syntax that relies on ``TypeVar``.
+Here the number of type arguments must match the number of free type variables
+in the generic type alias definition. A type variables is free if it's not
+a type parameter of a surrounding class or function. Example (following
+:pep:`PEP 484: Type aliases <484#type-aliases>`, Python 3.11 and earlier):
 
 .. code-block:: python
 
@@ -867,7 +1246,7 @@ variables replaced with ``Any``. Examples (following :pep:`PEP 484: Type aliases
 
     S = TypeVar('S')
 
-    TInt = tuple[int, S]
+    TInt = tuple[int, S]  # 1 type parameter, since only S is free
     UInt = Union[S, int]
     CBack = Callable[..., S]
 
@@ -894,7 +1273,36 @@ variables replaced with ``Any``. Examples (following :pep:`PEP 484: Type aliases
 Type aliases can be imported from modules just like other names. An
 alias can also target another alias, although building complex chains
 of aliases is not recommended -- this impedes code readability, thus
-defeating the purpose of using aliases.  Example:
+defeating the purpose of using aliases.  Example (Python 3.12 syntax):
+
+.. code-block:: python
+
+    from example1 import AliasType
+    from example2 import Vec
+
+    # AliasType and Vec are type aliases (Vec as defined above)
+
+    def fun() -> AliasType:
+        ...
+
+    type OIntVec = Vec[int] | None
+
+Type aliases defined using the ``type`` statement are not valid as
+base classes, and they can't be used to construct instances:
+
+.. code-block:: python
+
+    from example1 import AliasType
+    from example2 import Vec
+
+    # AliasType and Vec are type aliases (Vec as defined above)
+
+    class NewVec[T](Vec[T]):  # Error: not valid as base class
+        ...
+
+    x = AliasType()  # Error: can't be used to create instances
+
+Here are examples using the legacy syntax (Python 3.11 and earlier):
 
 .. code-block:: python
 
@@ -907,18 +1315,49 @@ defeating the purpose of using aliases.  Example:
     def fun() -> AliasType:
         ...
 
+    OIntVec = Optional[Vec[int]]
+
     T = TypeVar('T')
 
+    # Old-style type aliases can be used as base classes and you can
+    # construct instances using them
+
     class NewVec(Vec[T]):
         ...
 
+    x = AliasType()
+
     for i, j in NewVec[int]():
         ...
 
-    OIntVec = Optional[Vec[int]]
+Using type variable bounds or value restriction in generic aliases has
+the same effect as in generic classes and functions.
+
+
+Differences between the new and old syntax
+******************************************
 
-Using type variable bounds or values in generic aliases has the same effect
-as in generic classes/functions.
+There are a few notable differences between the new (Python 3.12 and later)
+and the old syntax for generic classes, functions and type aliases, beyond
+the obvious syntactic differences:
+
+ * Type variables defined using the old syntax create definitions at runtime
+   in the surrounding namespace, whereas the type variables defined using the
+   new syntax are only defined within the class, function or type variable
+   that uses them.
+ * Type variable definitions can be shared when using the old syntax, but
+   the new syntax doesn't support this.
+ * When using the new syntax, the variance of class type variables is always
+   inferred.
+ * Type aliases defined using the new syntax can contain forward references
+   and recursive references without using string literal escaping. The
+   same is true for the bounds and constraints of type variables.
+ * The new syntax lets you define a generic alias where the definition doesn't
+   contain a reference to a type parameter. This is occasionally useful, at
+   least when conditionally defining type aliases.
+ * Type aliases defined using the new syntax can't be used as base classes
+   and can't be used to construct instances, unlike aliases defined using the
+   old syntax.
 
 
 Generic class internals
@@ -926,7 +1365,20 @@ Generic class internals
 
 You may wonder what happens at runtime when you index a generic class.
 Indexing returns a *generic alias* to the original class that returns instances
-of the original class on instantiation:
+of the original class on instantiation (Python 3.12 syntax):
+
+.. code-block:: python
+
+   >>> class Stack[T]: ...
+   >>> Stack
+   __main__.Stack
+   >>> Stack[int]
+   __main__.Stack[int]
+   >>> instance = Stack[int]()
+   >>> instance.__class__
+   __main__.Stack
+
+Here is the same example using the legacy syntax (Python 3.11 and earlier):
 
 .. code-block:: python
 
@@ -945,10 +1397,17 @@ Generic aliases can be instantiated or subclassed, similar to real
 classes, but the above examples illustrate that type variables are
 erased at runtime. Generic ``Stack`` instances are just ordinary
 Python objects, and they have no extra runtime overhead or magic due
-to being generic, other than a metaclass that overloads the indexing
-operator.
+to being generic, other than the ``Generic`` base class that overloads
+the indexing operator using ``__class_getitem__``. ``typing.Generic``
+is included as an implicit base class even when using the new syntax:
+
+.. code-block:: python
+
+   >>> class Stack[T]: ...
+   >>> Stack.mro()
+   [<class '__main__.Stack'>, <class 'typing.Generic'>, <class 'object'>]
 
-Note that in Python 3.8 and lower, the built-in types
+Note that in Python 3.8 and earlier, the built-in types
 :py:class:`list`, :py:class:`dict` and others do not support indexing.
 This is why we have the aliases :py:class:`~typing.List`,
 :py:class:`~typing.Dict` and so on in the :py:mod:`typing`
@@ -959,16 +1418,18 @@ class in more recent versions of Python:
 .. code-block:: python
 
    >>> # Only relevant for Python 3.8 and below
-   >>> # For Python 3.9 onwards, prefer `list[int]` syntax
+   >>> # If using Python 3.9 or newer, prefer the 'list[int]' syntax
    >>> from typing import List
    >>> List[int]
    typing.List[int]
 
 Note that the generic aliases in ``typing`` don't support constructing
-instances:
+instances, unlike the corresponding built-in classes:
 
 .. code-block:: python
 
+   >>> list[int]()
+   []
    >>> from typing import List
    >>> List[int]()
    Traceback (most recent call last):
diff --git a/docs/source/getting_started.rst b/docs/source/getting_started.rst
index 049d7af003b5..28a4481e502e 100644
--- a/docs/source/getting_started.rst
+++ b/docs/source/getting_started.rst
@@ -186,19 +186,23 @@ For example, a ``RuntimeError`` instance can be passed to a function that is ann
 as taking an ``Exception``.
 
 As another example, suppose you want to write a function that can accept *either*
-ints or strings, but no other types. You can express this using the
-:py:data:`~typing.Union` type. For example, ``int`` is a subtype of ``Union[int, str]``:
+ints or strings, but no other types. You can express this using a
+union type. For example, ``int`` is a subtype of ``int | str``:
 
 .. code-block:: python
 
-   from typing import Union
-
-   def normalize_id(user_id: Union[int, str]) -> str:
+   def normalize_id(user_id: int | str) -> str:
        if isinstance(user_id, int):
            return f'user-{100_000 + user_id}'
        else:
            return user_id
 
+.. note::
+
+    If using Python 3.9 or earlier, use ``typing.Union[int, str]`` instead of
+    ``int | str``, or use ``from __future__ import annotations`` at the top of
+    the file (see :ref:`runtime_troubles`).
+
 The :py:mod:`typing` module contains many other useful types.
 
 For a quick overview, look through the :ref:`mypy cheatsheet <cheat-sheet-py3>`.
@@ -210,12 +214,12 @@ generic types or your own type aliases), look through the
 .. note::
 
    When adding types, the convention is to import types
-   using the form ``from typing import Union`` (as opposed to doing
+   using the form ``from typing import <name>`` (as opposed to doing
    just ``import typing`` or ``import typing as t`` or ``from typing import *``).
 
    For brevity, we often omit imports from :py:mod:`typing` or :py:mod:`collections.abc`
    in code examples, but mypy will give an error if you use types such as
-   :py:class:`~typing.Iterable` without first importing them.
+   :py:class:`~collections.abc.Iterable` without first importing them.
 
 .. note::
 
diff --git a/docs/source/index.rst b/docs/source/index.rst
index c9dc6bc1f8c9..de3286d58ace 100644
--- a/docs/source/index.rst
+++ b/docs/source/index.rst
@@ -103,6 +103,7 @@ Contents
    error_code_list2
    additional_features
    faq
+   changelog
 
 .. toctree::
    :hidden:
diff --git a/docs/source/kinds_of_types.rst b/docs/source/kinds_of_types.rst
index d07eb40753f3..54693cddf953 100644
--- a/docs/source/kinds_of_types.rst
+++ b/docs/source/kinds_of_types.rst
@@ -136,7 +136,7 @@ purpose. Example:
 .. note::
 
    Usually it's a better idea to use ``Sequence[T]`` instead of ``tuple[T, ...]``, as
-   :py:class:`~typing.Sequence` is also compatible with lists and other non-tuple sequences.
+   :py:class:`~collections.abc.Sequence` is also compatible with lists and other non-tuple sequences.
 
 .. note::
 
@@ -155,7 +155,7 @@ and returns ``Rt`` is ``Callable[[A1, ..., An], Rt]``. Example:
 
 .. code-block:: python
 
-   from typing import Callable
+   from collections.abc import Callable
 
    def twice(i: int, next: Callable[[int], int]) -> int:
        return next(next(i))
@@ -165,6 +165,11 @@ and returns ``Rt`` is ``Callable[[A1, ..., An], Rt]``. Example:
 
    print(twice(3, add))   # 5
 
+.. note::
+
+    Import :py:data:`Callable[...] <typing.Callable>` from ``typing`` instead
+    of ``collections.abc`` if you use Python 3.8 or earlier.
+
 You can only have positional arguments, and only ones without default
 values, in callable types. These cover the vast majority of uses of
 callable types, but sometimes this isn't quite enough. Mypy recognizes
@@ -178,7 +183,7 @@ Any)`` function signature. Example:
 
 .. code-block:: python
 
-   from typing import Callable
+   from collections.abc import Callable
 
    def arbitrary_call(f: Callable[..., int]) -> int:
        return f('x') + f(y=2)  # OK
@@ -205,7 +210,7 @@ Callables can also be used against type objects, matching their
 
 .. code-block:: python
 
-    from typing import Callable
+    from collections.abc import Callable
 
     class C:
         def __init__(self, app: str) -> None:
@@ -223,6 +228,7 @@ instance of ``C`` or the type of ``C`` itself. This also works with
 
 
 .. _union-types:
+.. _alternative_union_syntax:
 
 Union types
 ***********
@@ -231,8 +237,8 @@ Python functions often accept values of two or more different
 types. You can use :ref:`overloading <function-overloading>` to
 represent this, but union types are often more convenient.
 
-Use the ``Union[T1, ..., Tn]`` type constructor to construct a union
-type. For example, if an argument has type ``Union[int, str]``, both
+Use ``T1 | ... | Tn`` to construct a union
+type. For example, if an argument has type ``int | str``, both
 integers and strings are valid argument values.
 
 You can use an :py:func:`isinstance` check to narrow down a union type to a
@@ -240,9 +246,7 @@ more specific type:
 
 .. code-block:: python
 
-   from typing import Union
-
-   def f(x: Union[int, str]) -> None:
+   def f(x: int | str) -> None:
        x + 1     # Error: str + int is not valid
        if isinstance(x, int):
            # Here type of x is int.
@@ -264,20 +268,38 @@ more specific type:
     since the caller may have to use :py:func:`isinstance` before doing anything
     interesting with the value.
 
+Python 3.9 and older only partially support this syntax. Instead, you can
+use the legacy ``Union[T1, ..., Tn]`` type constructor. Example:
+
+.. code-block:: python
+
+   from typing import Union
+
+   def f(x: Union[int, str]) -> None:
+       ...
+
+It is also possible to use the new syntax with versions of Python where it
+isn't supported by the runtime with some limitations, if you use
+``from __future__ import annotations`` (see :ref:`runtime_troubles`):
+
+.. code-block:: python
+
+   from __future__ import annotations
+
+   def f(x: int | str) -> None:   # OK on Python 3.7 and later
+       ...
+
 .. _strict_optional:
 
 Optional types and the None type
 ********************************
 
-You can use the :py:data:`~typing.Optional` type modifier to define a type variant
-that allows ``None``, such as ``Optional[int]`` (``Optional[X]`` is
-the preferred shorthand for ``Union[X, None]``):
+You can use ``T | None`` to define a type variant that allows ``None`` values,
+such as ``int | None``. This is called an *optional type*:
 
 .. code-block:: python
 
-   from typing import Optional
-
-   def strlen(s: str) -> Optional[int]:
+   def strlen(s: str) -> int | None:
        if not s:
            return None  # OK
        return len(s)
@@ -287,12 +309,23 @@ the preferred shorthand for ``Union[X, None]``):
            return None  # Error: None not compatible with int
        return len(s)
 
-Most operations will not be allowed on unguarded ``None`` or :py:data:`~typing.Optional`
-values:
+To support Python 3.9 and earlier, you can use the :py:data:`~typing.Optional`
+type modifier instead, such as ``Optional[int]`` (``Optional[X]`` is
+the preferred shorthand for ``Union[X, None]``):
 
 .. code-block:: python
 
-   def my_inc(x: Optional[int]) -> int:
+   from typing import Optional
+
+   def strlen(s: str) -> Optional[int]:
+       ...
+
+Most operations will not be allowed on unguarded ``None`` or *optional* values
+(values with an optional type):
+
+.. code-block:: python
+
+   def my_inc(x: int | None) -> int:
        return x + 1  # Error: Cannot add None and int
 
 Instead, an explicit ``None`` check is required. Mypy has
@@ -302,7 +335,7 @@ recognizes ``is None`` checks:
 
 .. code-block:: python
 
-   def my_inc(x: Optional[int]) -> int:
+   def my_inc(x: int | None) -> int:
        if x is None:
            return 0
        else:
@@ -318,7 +351,7 @@ Other supported checks for guarding against a ``None`` value include
 
 .. code-block:: python
 
-   def concat(x: Optional[str], y: Optional[str]) -> Optional[str]:
+   def concat(x: str | None, y: str | None) -> str | None:
        if x is not None and y is not None:
            # Both x and y are not None here
            return x + y
@@ -335,7 +368,7 @@ will complain about the possible ``None`` value. You can use
 .. code-block:: python
 
    class Resource:
-       path: Optional[str] = None
+       path: str | None = None
 
        def initialize(self, path: str) -> None:
            self.path = path
@@ -358,7 +391,7 @@ This is why you need to annotate an attribute in cases like the class
 .. code-block:: python
 
     class Resource:
-        path: Optional[str] = None
+        path: str | None = None
         ...
 
 This also works for attributes defined within methods:
@@ -367,10 +400,11 @@ This also works for attributes defined within methods:
 
     class Counter:
         def __init__(self) -> None:
-            self.count: Optional[int] = None
+            self.count: int | None = None
 
-This is not a problem when using variable annotations, since no initial
-value is needed:
+Often it's easier to not use any initial value for an attribute.
+This way you don't need to use an optional type and can avoid ``assert ... is not None``
+checks. No initial value is needed if you annotate an attribute in the class body:
 
 .. code-block:: python
 
@@ -385,13 +419,13 @@ the right thing without an annotation:
 .. code-block:: python
 
    def f(i: int) -> None:
-       n = None  # Inferred type Optional[int] because of the assignment below
+       n = None  # Inferred type 'int | None' because of the assignment below
        if i > 0:
             n = i
        ...
 
 Sometimes you may get the error "Cannot determine type of <something>". In this
-case you should add an explicit ``Optional[...]`` annotation (or type comment).
+case you should add an explicit ``... | None`` annotation.
 
 .. note::
 
@@ -409,44 +443,31 @@ case you should add an explicit ``Optional[...]`` annotation (or type comment).
 
 .. note::
 
-    ``Optional[...]`` *does not* mean a function argument with a default value.
-    It simply means that ``None`` is a valid value for the argument. This is
-    a common confusion because ``None`` is a common default value for arguments.
-
-.. _alternative_union_syntax:
-
-X | Y syntax for Unions
------------------------
-
-:pep:`604` introduced an alternative way for spelling union types. In Python
-3.10 and later, you can write ``Union[int, str]`` as ``int | str``. It is
-possible to use this syntax in versions of Python where it isn't supported by
-the runtime with some limitations (see :ref:`runtime_troubles`).
-
-.. code-block:: python
-
-    t1: int | str  # equivalent to Union[int, str]
-
-    t2: int | None  # equivalent to Optional[int]
+    The type ``Optional[T]`` *does not* mean a function parameter with a default value.
+    It simply means that ``None`` is a valid argument value. This is
+    a common confusion because ``None`` is a common default value for parameters,
+    and parameters with default values are sometimes called *optional* parameters
+    (or arguments).
 
 .. _type-aliases:
 
 Type aliases
 ************
 
-In certain situations, type names may end up being long and painful to type:
+In certain situations, type names may end up being long and painful to type,
+especially if they are used frequently:
 
 .. code-block:: python
 
-   def f() -> Union[list[dict[tuple[int, str], set[int]]], tuple[str, list[str]]]:
+   def f() -> list[dict[tuple[int, str], set[int]]] | tuple[str, list[str]]:
        ...
 
 When cases like this arise, you can define a type alias by simply
-assigning the type to a variable:
+assigning the type to a variable (this is an *implicit type alias*):
 
 .. code-block:: python
 
-   AliasType = Union[list[dict[tuple[int, str], set[int]]], tuple[str, list[str]]]
+   AliasType = list[dict[tuple[int, str], set[int]]] | tuple[str, list[str]]
 
    # Now we can use AliasType in place of the full name:
 
@@ -459,8 +480,18 @@ assigning the type to a variable:
     another type -- it's equivalent to the target type except for
     :ref:`generic aliases <generic-type-aliases>`.
 
-Since Mypy 0.930 you can also use *explicit type aliases*, which were
-introduced in :pep:`613`.
+Python 3.12 introduced the ``type`` statement for defining *explicit type aliases*.
+Explicit type aliases are unambiguous and can also improve readability by
+making the intent clear:
+
+.. code-block:: python
+
+   type AliasType = list[dict[tuple[int, str], set[int]]] | tuple[str, list[str]]
+
+   # Now we can use AliasType in place of the full name:
+
+   def f() -> AliasType:
+       ...
 
 There can be confusion about exactly when an assignment defines an implicit type alias --
 for example, when the alias contains forward references, invalid types, or violates some other
@@ -469,14 +500,23 @@ distinction between an unannotated variable and a type alias is implicit,
 ambiguous or incorrect type alias declarations default to defining
 a normal variable instead of a type alias.
 
-Explicit type aliases are unambiguous and can also improve readability by
-making the intent clear:
+Aliases defined using the ``type`` statement have these properties, which
+distinguish them from implicit type aliases:
+
+* The definition may contain forward references without having to use string
+  literal escaping, since it is evaluated lazily.
+* The alias can be used in type annotations, type arguments, and casts, but
+  it can't be used in contexts which require a class object. For example, it's
+  not valid as a base class and it can't be used to construct instances.
+
+There is also use an older syntax for defining explicit type aliases, which was
+introduced in Python 3.10 (:pep:`613`):
 
 .. code-block:: python
 
    from typing import TypeAlias  # "from typing_extensions" in Python 3.9 and earlier
 
-   AliasType: TypeAlias = Union[list[dict[tuple[int, str], set[int]]], tuple[str, list[str]]]
+   AliasType: TypeAlias = list[dict[tuple[int, str], set[int]]] | tuple[str, list[str]]
 
 .. _named-tuples:
 
@@ -604,14 +644,21 @@ doesn't see that the ``buyer`` variable has type ``ProUser``:
    buyer.pay()  # Rejected, not a method on User
 
 However, using the ``type[C]`` syntax and a type variable with an upper bound (see
-:ref:`type-variable-upper-bound`) we can do better:
+:ref:`type-variable-upper-bound`) we can do better (Python 3.12 syntax):
+
+.. code-block:: python
+
+   def new_user[U: User](user_class: type[U]) -> U:
+       # Same implementation as before
+
+Here is the example using the legacy syntax (Python 3.11 and earlier):
 
 .. code-block:: python
 
    U = TypeVar('U', bound=User)
 
    def new_user(user_class: type[U]) -> U:
-       # Same  implementation as before
+       # Same implementation as before
 
 Now mypy will infer the correct type of the result when we call
 ``new_user()`` with a specific subclass of ``User``:
diff --git a/docs/source/literal_types.rst b/docs/source/literal_types.rst
index 283bf7f9dba1..877ab5de9087 100644
--- a/docs/source/literal_types.rst
+++ b/docs/source/literal_types.rst
@@ -70,7 +70,7 @@ complex types involving literals a little more convenient.
 
 Literal types may also contain ``None``. Mypy will treat ``Literal[None]`` as being
 equivalent to just ``None``. This means that ``Literal[4, None]``,
-``Union[Literal[4], None]``, and ``Optional[Literal[4]]`` are all equivalent.
+``Literal[4] | None``, and ``Optional[Literal[4]]`` are all equivalent.
 
 Literals may also contain aliases to other literal types. For example, the
 following program is legal:
@@ -264,19 +264,15 @@ use the same technique with regular objects, tuples, or namedtuples.
 Similarly, tags do not need to be specifically str Literals: they can be any type
 you can normally narrow within ``if`` statements and the like. For example, you
 could have your tags be int or Enum Literals or even regular classes you narrow
-using ``isinstance()``:
+using ``isinstance()`` (Python 3.12 syntax):
 
 .. code-block:: python
 
-    from typing import Generic, TypeVar, Union
-
-    T = TypeVar('T')
-
-    class Wrapper(Generic[T]):
+    class Wrapper[T]:
         def __init__(self, inner: T) -> None:
             self.inner = inner
 
-    def process(w: Union[Wrapper[int], Wrapper[str]]) -> None:
+    def process(w: Wrapper[int] | Wrapper[str]) -> None:
         # Doing `if isinstance(w, Wrapper[int])` does not work: isinstance requires
         # that the second argument always be an *erased* type, with no generics.
         # This is because generics are a typing-only concept and do not exist at
diff --git a/docs/source/metaclasses.rst b/docs/source/metaclasses.rst
index 396d7dbb42cc..a3ee25f16054 100644
--- a/docs/source/metaclasses.rst
+++ b/docs/source/metaclasses.rst
@@ -34,13 +34,12 @@ Mypy supports the lookup of attributes in the metaclass:
 
 .. code-block:: python
 
-    from typing import Type, TypeVar, ClassVar
-    T = TypeVar('T')
+    from typing import ClassVar, Self
 
     class M(type):
         count: ClassVar[int] = 0
 
-        def make(cls: Type[T]) -> T:
+        def make(cls) -> Self:
             M.count += 1
             return cls()
 
@@ -56,6 +55,9 @@ Mypy supports the lookup of attributes in the metaclass:
     b: B = B.make()  # metaclasses are inherited
     print(B.count + " objects were created")  # Error: Unsupported operand types for + ("int" and "str")
 
+.. note::
+    In Python 3.10 and earlier, ``Self`` is available in ``typing_extensions``.
+
 .. _limitations:
 
 Gotchas and limitations of metaclass support
diff --git a/docs/source/more_types.rst b/docs/source/more_types.rst
index cb3ef64b39a7..cbf40d5dcaa5 100644
--- a/docs/source/more_types.rst
+++ b/docs/source/more_types.rst
@@ -116,7 +116,7 @@ implicitly casting from ``UserId`` where ``int`` is expected. Examples:
 :py:class:`~typing.NewType` accepts exactly two arguments. The first argument must be a string literal
 containing the name of the new type and must equal the name of the variable to which the new
 type is assigned. The second argument must be a properly subclassable class, i.e.,
-not a type construct like :py:data:`~typing.Union`, etc.
+not a type construct like a :ref:`union type <union-types>`, etc.
 
 The callable returned by :py:class:`~typing.NewType` accepts only one argument; this is equivalent to
 supporting only one constructor accepting an instance of the base class (see above).
@@ -179,7 +179,7 @@ Function overloading
 ********************
 
 Sometimes the arguments and types in a function depend on each other
-in ways that can't be captured with a :py:data:`~typing.Union`. For example, suppose
+in ways that can't be captured with a :ref:`union types <union-types>`. For example, suppose
 we want to write a function that can accept x-y coordinates. If we pass
 in just a single x-y coordinate, we return a ``ClickEvent`` object. However,
 if we pass in two x-y coordinates, we return a ``DragEvent`` object.
@@ -188,12 +188,10 @@ Our first attempt at writing this function might look like this:
 
 .. code-block:: python
 
-    from typing import Union, Optional
-
     def mouse_event(x1: int,
                     y1: int,
-                    x2: Optional[int] = None,
-                    y2: Optional[int] = None) -> Union[ClickEvent, DragEvent]:
+                    x2: int | None = None,
+                    y2: int | None = None) -> ClickEvent | DragEvent:
         if x2 is None and y2 is None:
             return ClickEvent(x1, y1)
         elif x2 is not None and y2 is not None:
@@ -213,7 +211,7 @@ to more accurately describe the function's behavior:
 
 .. code-block:: python
 
-    from typing import Union, overload
+    from typing import overload
 
     # Overload *variants* for 'mouse_event'.
     # These variants give extra information to the type checker.
@@ -236,8 +234,8 @@ to more accurately describe the function's behavior:
 
     def mouse_event(x1: int,
                     y1: int,
-                    x2: Optional[int] = None,
-                    y2: Optional[int] = None) -> Union[ClickEvent, DragEvent]:
+                    x2: int | None = None,
+                    y2: int | None = None) -> ClickEvent | DragEvent:
         if x2 is None and y2 is None:
             return ClickEvent(x1, y1)
         elif x2 is not None and y2 is not None:
@@ -253,14 +251,37 @@ calls like ``mouse_event(5, 25, 2)``.
 As another example, suppose we want to write a custom container class that
 implements the :py:meth:`__getitem__ <object.__getitem__>` method (``[]`` bracket indexing). If this
 method receives an integer we return a single item. If it receives a
-``slice``, we return a :py:class:`~typing.Sequence` of items.
+``slice``, we return a :py:class:`~collections.abc.Sequence` of items.
 
 We can precisely encode this relationship between the argument and the
-return type by using overloads like so:
+return type by using overloads like so (Python 3.12 syntax):
+
+.. code-block:: python
+
+    from collections.abc import Sequence
+    from typing import overload
+
+    class MyList[T](Sequence[T]):
+        @overload
+        def __getitem__(self, index: int) -> T: ...
+
+        @overload
+        def __getitem__(self, index: slice) -> Sequence[T]: ...
+
+        def __getitem__(self, index: int | slice) -> T | Sequence[T]:
+            if isinstance(index, int):
+                # Return a T here
+            elif isinstance(index, slice):
+                # Return a sequence of Ts here
+            else:
+                raise TypeError(...)
+
+Here is the same example using the legacy syntax (Python 3.11 and earlier):
 
 .. code-block:: python
 
-    from typing import Sequence, TypeVar, Union, overload
+    from collections.abc import Sequence
+    from typing import TypeVar, overload
 
     T = TypeVar('T')
 
@@ -271,7 +292,7 @@ return type by using overloads like so:
         @overload
         def __getitem__(self, index: slice) -> Sequence[T]: ...
 
-        def __getitem__(self, index: Union[int, slice]) -> Union[T, Sequence[T]]:
+        def __getitem__(self, index: int | slice) -> T | Sequence[T]:
             if isinstance(index, int):
                 # Return a T here
             elif isinstance(index, slice):
@@ -389,9 +410,9 @@ matching variant returns:
 
 .. code-block:: python
 
-    some_list: Union[list[int], list[str]]
+    some_list: list[int] | list[str]
 
-    # output3 is of type 'Union[float, str]'
+    # output3 is of type 'float | str'
     output3 = summarize(some_list)
 
 .. note::
@@ -418,7 +439,7 @@ types:
 
 .. code-block:: python
 
-    from typing import overload, Union
+    from typing import overload
 
     class Expression:
         # ...snip...
@@ -469,7 +490,7 @@ the following unsafe overload definition:
 
 .. code-block:: python
 
-    from typing import overload, Union
+    from typing import overload
 
     @overload
     def unsafe_func(x: int) -> int: ...
@@ -477,7 +498,7 @@ the following unsafe overload definition:
     @overload
     def unsafe_func(x: object) -> str: ...
 
-    def unsafe_func(x: object) -> Union[int, str]:
+    def unsafe_func(x: object) -> int | str:
         if isinstance(x, int):
             return 42
         else:
@@ -546,8 +567,8 @@ Type checking the implementation
 The body of an implementation is type-checked against the
 type hints provided on the implementation. For example, in the
 ``MyList`` example up above, the code in the body is checked with
-argument list ``index: Union[int, slice]`` and a return type of
-``Union[T, Sequence[T]]``. If there are no annotations on the
+argument list ``index: int | slice`` and a return type of
+``T | Sequence[T]``. If there are no annotations on the
 implementation, then the body is not type checked. If you want to
 force mypy to check the body anyways, use the :option:`--check-untyped-defs <mypy --check-untyped-defs>`
 flag (:ref:`more details here <untyped-definitions-and-calls>`).
@@ -555,10 +576,10 @@ flag (:ref:`more details here <untyped-definitions-and-calls>`).
 The variants must also also be compatible with the implementation
 type hints. In the ``MyList`` example, mypy will check that the
 parameter type ``int`` and the return type ``T`` are compatible with
-``Union[int, slice]`` and ``Union[T, Sequence]`` for the
+``int | slice`` and ``T | Sequence`` for the
 first variant. For the second variant it verifies the parameter
 type ``slice`` and the return type ``Sequence[T]`` are compatible
-with ``Union[int, slice]`` and ``Union[T, Sequence]``.
+with ``int | slice`` and ``T | Sequence``.
 
 .. note::
 
@@ -697,14 +718,13 @@ Restricted methods in generic classes
 -------------------------------------
 
 In generic classes some methods may be allowed to be called only
-for certain values of type arguments:
+for certain values of type arguments (Python 3.12 syntax):
 
 .. code-block:: python
 
-   T = TypeVar('T')
-
-   class Tag(Generic[T]):
+   class Tag[T]:
        item: T
+
        def uppercase_item(self: Tag[str]) -> str:
            return self.item.upper()
 
@@ -714,18 +734,18 @@ for certain values of type arguments:
        ts.uppercase_item()  # This is OK
 
 This pattern also allows matching on nested types in situations where the type
-argument is itself generic:
+argument is itself generic (Python 3.12 syntax):
 
 .. code-block:: python
 
-  T = TypeVar('T', covariant=True)
-  S = TypeVar('S')
+   from collections.abc import Sequence
 
-   class Storage(Generic[T]):
+   class Storage[T]:
        def __init__(self, content: T) -> None:
-           self.content = content
-       def first_chunk(self: Storage[Sequence[S]]) -> S:
-           return self.content[0]
+           self._content = content
+
+       def first_chunk[S](self: Storage[Sequence[S]]) -> S:
+           return self._content[0]
 
    page: Storage[list[str]]
    page.first_chunk()  # OK, type is "str"
@@ -734,13 +754,14 @@ argument is itself generic:
                              # "first_chunk" with type "Callable[[Storage[Sequence[S]]], S]"
 
 Finally, one can use overloads on self-type to express precise types of
-some tricky methods:
+some tricky methods (Python 3.12 syntax):
 
 .. code-block:: python
 
-   T = TypeVar('T')
+   from collections.abc import Callable
+   from typing import overload
 
-   class Tag(Generic[T]):
+   class Tag[T]:
        @overload
        def export(self: Tag[str]) -> str: ...
        @overload
@@ -799,23 +820,22 @@ Precise typing of alternative constructors
 ------------------------------------------
 
 Some classes may define alternative constructors. If these
-classes are generic, self-type allows giving them precise signatures:
+classes are generic, self-type allows giving them precise
+signatures (Python 3.12 syntax):
 
 .. code-block:: python
 
-   T = TypeVar('T')
-
-   class Base(Generic[T]):
-       Q = TypeVar('Q', bound='Base[T]')
+   from typing import Self
 
+   class Base[T]:
        def __init__(self, item: T) -> None:
            self.item = item
 
        @classmethod
-       def make_pair(cls: Type[Q], item: T) -> tuple[Q, Q]:
+       def make_pair(cls, item: T) -> tuple[Self, Self]:
            return cls(item), cls(item)
 
-   class Sub(Base[T]):
+   class Sub[T](Base[T]):
        ...
 
    pair = Sub.make_pair('yes')  # Type is "tuple[Sub[str], Sub[str]]"
@@ -854,8 +874,8 @@ expect to get back when ``await``-ing the coroutine.
 
 The result of calling an ``async def`` function *without awaiting* will
 automatically be inferred to be a value of type
-:py:class:`Coroutine[Any, Any, T] <typing.Coroutine>`, which is a subtype of
-:py:class:`Awaitable[T] <typing.Awaitable>`:
+:py:class:`Coroutine[Any, Any, T] <collections.abc.Coroutine>`, which is a subtype of
+:py:class:`Awaitable[T] <collections.abc.Awaitable>`:
 
 .. code-block:: python
 
@@ -868,11 +888,12 @@ Asynchronous iterators
 ----------------------
 
 If you have an asynchronous iterator, you can use the
-:py:class:`~typing.AsyncIterator` type in your annotations:
+:py:class:`~collections.abc.AsyncIterator` type in your annotations:
 
 .. code-block:: python
 
-   from typing import Optional, AsyncIterator
+   from collections.abc import AsyncIterator
+   from typing import Optional
    import asyncio
 
    class arange:
@@ -905,7 +926,8 @@ async iterators:
 
 .. code-block:: python
 
-   from typing import AsyncGenerator, Optional
+   from collections.abc import AsyncGenerator
+   from typing import Optional
    import asyncio
 
    # Could also type this as returning AsyncIterator[int]
@@ -922,7 +944,7 @@ One common confusion is that the presence of a ``yield`` statement in an
 
 .. code-block:: python
 
-   from typing import AsyncIterator
+   from collections.abc import AsyncIterator
 
    async def arange(stop: int) -> AsyncIterator[int]:
        # When called, arange gives you an async iterator
@@ -948,7 +970,8 @@ This can sometimes come up when trying to define base classes, Protocols or over
 
 .. code-block:: python
 
-    from typing import AsyncIterator, Protocol, overload
+    from collections.abc import AsyncIterator
+    from typing import Protocol, overload
 
     class LauncherIncorrect(Protocol):
         # Because launch does not have yield, this has type
diff --git a/docs/source/protocols.rst b/docs/source/protocols.rst
index 731562867691..ed8d94f62ef1 100644
--- a/docs/source/protocols.rst
+++ b/docs/source/protocols.rst
@@ -27,18 +27,21 @@ of protocols and structural subtyping in Python.
 Predefined protocols
 ********************
 
-The :py:mod:`typing` module defines various protocol classes that correspond
-to common Python protocols, such as :py:class:`Iterable[T] <typing.Iterable>`. If a class
+The :py:mod:`collections.abc`, :py:mod:`typing` and other stdlib modules define
+various protocol classes that correspond to common Python protocols, such as
+:py:class:`Iterable[T] <collections.abc.Iterable>`. If a class
 defines a suitable :py:meth:`__iter__ <object.__iter__>` method, mypy understands that it
-implements the iterable protocol and is compatible with :py:class:`Iterable[T] <typing.Iterable>`.
+implements the iterable protocol and is compatible with :py:class:`Iterable[T] <collections.abc.Iterable>`.
 For example, ``IntList`` below is iterable, over ``int`` values:
 
 .. code-block:: python
 
-   from typing import Iterator, Iterable, Optional
+   from __future__ import annotations
+
+   from collections.abc import Iterator, Iterable
 
    class IntList:
-       def __init__(self, value: int, next: Optional['IntList']) -> None:
+       def __init__(self, value: int, next: IntList | None) -> None:
            self.value = value
            self.next = next
 
@@ -56,9 +59,18 @@ For example, ``IntList`` below is iterable, over ``int`` values:
    print_numbered(x)  # OK
    print_numbered([4, 5])  # Also OK
 
-:ref:`predefined_protocols_reference` lists all protocols defined in
-:py:mod:`typing` and the signatures of the corresponding methods you need to define
-to implement each protocol.
+:ref:`predefined_protocols_reference` lists various protocols defined in
+:py:mod:`collections.abc` and :py:mod:`typing` and the signatures of the corresponding methods
+you need to define to implement each protocol.
+
+.. note::
+    ``typing`` also contains deprecated aliases to protocols and ABCs defined in
+    :py:mod:`collections.abc`, such as :py:class:`Iterable[T] <typing.Iterable>`.
+    These are only necessary in Python 3.8 and earlier, since the protocols in
+    ``collections.abc`` didn't yet support subscripting (``[]``) in Python 3.8,
+    but the aliases in ``typing`` have always supported
+    subscripting. In Python 3.9 and later, the aliases in ``typing`` don't provide
+    any extra functionality.
 
 Simple user-defined protocols
 *****************************
@@ -68,7 +80,8 @@ class:
 
 .. code-block:: python
 
-   from typing import Iterable, Protocol
+   from collections.abc import Iterable
+   from typing import Protocol
 
    class SupportsClose(Protocol):
        # Empty method body (explicit '...')
@@ -225,22 +238,24 @@ such as trees and linked lists:
 
 .. code-block:: python
 
-   from typing import TypeVar, Optional, Protocol
+   from __future__ import annotations
+
+   from typing import Protocol
 
    class TreeLike(Protocol):
        value: int
 
        @property
-       def left(self) -> Optional['TreeLike']: ...
+       def left(self) -> TreeLike | None: ...
 
        @property
-       def right(self) -> Optional['TreeLike']: ...
+       def right(self) -> TreeLike | None: ...
 
    class SimpleTree:
        def __init__(self, value: int) -> None:
            self.value = value
-           self.left: Optional['SimpleTree'] = None
-           self.right: Optional['SimpleTree'] = None
+           self.left: SimpleTree | None = None
+           self.right: SimpleTree | None = None
 
    root: TreeLike = SimpleTree(0)  # OK
 
@@ -290,42 +305,46 @@ Callback protocols
 ******************
 
 Protocols can be used to define flexible callback types that are hard
-(or even impossible) to express using the :py:data:`Callable[...] <typing.Callable>` syntax, such as variadic,
-overloaded, and complex generic callbacks. They are defined with a special :py:meth:`__call__ <object.__call__>`
-member:
+(or even impossible) to express using the
+:py:class:`Callable[...] <collections.abc.Callable>` syntax,
+such as variadic, overloaded, and complex generic callbacks. They are defined with a
+special :py:meth:`__call__ <object.__call__>` member:
 
 .. code-block:: python
 
-   from typing import Optional, Iterable, Protocol
+   from collections.abc import Iterable
+   from typing import Optional, Protocol
 
    class Combiner(Protocol):
-       def __call__(self, *vals: bytes, maxlen: Optional[int] = None) -> list[bytes]: ...
+       def __call__(self, *vals: bytes, maxlen: int | None = None) -> list[bytes]: ...
 
    def batch_proc(data: Iterable[bytes], cb_results: Combiner) -> bytes:
        for item in data:
            ...
 
-   def good_cb(*vals: bytes, maxlen: Optional[int] = None) -> list[bytes]:
+   def good_cb(*vals: bytes, maxlen: int | None = None) -> list[bytes]:
        ...
-   def bad_cb(*vals: bytes, maxitems: Optional[int]) -> list[bytes]:
+   def bad_cb(*vals: bytes, maxitems: int | None) -> list[bytes]:
        ...
 
    batch_proc([], good_cb)  # OK
    batch_proc([], bad_cb)   # Error! Argument 2 has incompatible type because of
                             # different name and kind in the callback
 
-Callback protocols and :py:data:`~typing.Callable` types can be used mostly interchangeably.
-Argument names in :py:meth:`__call__ <object.__call__>` methods must be identical, unless
-a double underscore prefix is used. For example:
+Callback protocols and :py:class:`~collections.abc.Callable` types can be used mostly interchangeably.
+Parameter names in :py:meth:`__call__ <object.__call__>` methods must be identical, unless
+the parameters are positional-only. Example (using the legacy syntax for generic functions):
 
 .. code-block:: python
 
-   from typing import Callable, Protocol, TypeVar
+   from collections.abc import Callable
+   from typing import Protocol, TypeVar
 
    T = TypeVar('T')
 
    class Copy(Protocol):
-       def __call__(self, __origin: T) -> T: ...
+       # '/' marks the end of positional-only parameters
+       def __call__(self, origin: T, /) -> T: ...
 
    copy_a: Callable[[T], T]
    copy_b: Copy
@@ -344,8 +363,8 @@ Iteration protocols
 The iteration protocols are useful in many contexts. For example, they allow
 iteration of objects in for loops.
 
-Iterable[T]
------------
+collections.abc.Iterable[T]
+---------------------------
 
 The :ref:`example above <predefined_protocols>` has a simple implementation of an
 :py:meth:`__iter__ <object.__iter__>` method.
@@ -354,17 +373,17 @@ The :ref:`example above <predefined_protocols>` has a simple implementation of a
 
    def __iter__(self) -> Iterator[T]
 
-See also :py:class:`~typing.Iterable`.
+See also :py:class:`~collections.abc.Iterable`.
 
-Iterator[T]
------------
+collections.abc.Iterator[T]
+---------------------------
 
 .. code-block:: python
 
    def __next__(self) -> T
    def __iter__(self) -> Iterator[T]
 
-See also :py:class:`~typing.Iterator`.
+See also :py:class:`~collections.abc.Iterator`.
 
 Collection protocols
 ....................
@@ -373,8 +392,8 @@ Many of these are implemented by built-in container types such as
 :py:class:`list` and :py:class:`dict`, and these are also useful for user-defined
 collection objects.
 
-Sized
------
+collections.abc.Sized
+---------------------
 
 This is a type for objects that support :py:func:`len(x) <len>`.
 
@@ -382,10 +401,10 @@ This is a type for objects that support :py:func:`len(x) <len>`.
 
    def __len__(self) -> int
 
-See also :py:class:`~typing.Sized`.
+See also :py:class:`~collections.abc.Sized`.
 
-Container[T]
-------------
+collections.abc.Container[T]
+----------------------------
 
 This is a type for objects that support the ``in`` operator.
 
@@ -393,10 +412,10 @@ This is a type for objects that support the ``in`` operator.
 
    def __contains__(self, x: object) -> bool
 
-See also :py:class:`~typing.Container`.
+See also :py:class:`~collections.abc.Container`.
 
-Collection[T]
--------------
+collections.abc.Collection[T]
+-----------------------------
 
 .. code-block:: python
 
@@ -404,7 +423,7 @@ Collection[T]
    def __iter__(self) -> Iterator[T]
    def __contains__(self, x: object) -> bool
 
-See also :py:class:`~typing.Collection`.
+See also :py:class:`~collections.abc.Collection`.
 
 One-off protocols
 .................
@@ -412,8 +431,8 @@ One-off protocols
 These protocols are typically only useful with a single standard
 library function or class.
 
-Reversible[T]
--------------
+collections.abc.Reversible[T]
+-----------------------------
 
 This is a type for objects that support :py:func:`reversed(x) <reversed>`.
 
@@ -421,10 +440,10 @@ This is a type for objects that support :py:func:`reversed(x) <reversed>`.
 
    def __reversed__(self) -> Iterator[T]
 
-See also :py:class:`~typing.Reversible`.
+See also :py:class:`~collections.abc.Reversible`.
 
-SupportsAbs[T]
---------------
+typing.SupportsAbs[T]
+---------------------
 
 This is a type for objects that support :py:func:`abs(x) <abs>`. ``T`` is the type of
 value returned by :py:func:`abs(x) <abs>`.
@@ -435,8 +454,8 @@ value returned by :py:func:`abs(x) <abs>`.
 
 See also :py:class:`~typing.SupportsAbs`.
 
-SupportsBytes
--------------
+typing.SupportsBytes
+--------------------
 
 This is a type for objects that support :py:class:`bytes(x) <bytes>`.
 
@@ -448,8 +467,8 @@ See also :py:class:`~typing.SupportsBytes`.
 
 .. _supports-int-etc:
 
-SupportsComplex
----------------
+typing.SupportsComplex
+----------------------
 
 This is a type for objects that support :py:class:`complex(x) <complex>`. Note that no arithmetic operations
 are supported.
@@ -460,8 +479,8 @@ are supported.
 
 See also :py:class:`~typing.SupportsComplex`.
 
-SupportsFloat
--------------
+typing.SupportsFloat
+--------------------
 
 This is a type for objects that support :py:class:`float(x) <float>`. Note that no arithmetic operations
 are supported.
@@ -472,8 +491,8 @@ are supported.
 
 See also :py:class:`~typing.SupportsFloat`.
 
-SupportsInt
------------
+typing.SupportsInt
+------------------
 
 This is a type for objects that support :py:class:`int(x) <int>`. Note that no arithmetic operations
 are supported.
@@ -484,8 +503,8 @@ are supported.
 
 See also :py:class:`~typing.SupportsInt`.
 
-SupportsRound[T]
-----------------
+typing.SupportsRound[T]
+-----------------------
 
 This is a type for objects that support :py:func:`round(x) <round>`.
 
@@ -501,33 +520,33 @@ Async protocols
 These protocols can be useful in async code. See :ref:`async-and-await`
 for more information.
 
-Awaitable[T]
-------------
+collections.abc.Awaitable[T]
+----------------------------
 
 .. code-block:: python
 
    def __await__(self) -> Generator[Any, None, T]
 
-See also :py:class:`~typing.Awaitable`.
+See also :py:class:`~collections.abc.Awaitable`.
 
-AsyncIterable[T]
-----------------
+collections.abc.AsyncIterable[T]
+--------------------------------
 
 .. code-block:: python
 
    def __aiter__(self) -> AsyncIterator[T]
 
-See also :py:class:`~typing.AsyncIterable`.
+See also :py:class:`~collections.abc.AsyncIterable`.
 
-AsyncIterator[T]
-----------------
+collections.abc.AsyncIterator[T]
+--------------------------------
 
 .. code-block:: python
 
    def __anext__(self) -> Awaitable[T]
    def __aiter__(self) -> AsyncIterator[T]
 
-See also :py:class:`~typing.AsyncIterator`.
+See also :py:class:`~collections.abc.AsyncIterator`.
 
 Context manager protocols
 .........................
@@ -536,28 +555,28 @@ There are two protocols for context managers -- one for regular context
 managers and one for async ones. These allow defining objects that can
 be used in ``with`` and ``async with`` statements.
 
-ContextManager[T]
------------------
+contextlib.AbstractContextManager[T]
+------------------------------------
 
 .. code-block:: python
 
    def __enter__(self) -> T
    def __exit__(self,
-                exc_type: Optional[Type[BaseException]],
-                exc_value: Optional[BaseException],
-                traceback: Optional[TracebackType]) -> Optional[bool]
+                exc_type: type[BaseException] | None,
+                exc_value: BaseException | None,
+                traceback: TracebackType | None) -> bool | None
 
-See also :py:class:`~typing.ContextManager`.
+See also :py:class:`~contextlib.AbstractContextManager`.
 
-AsyncContextManager[T]
-----------------------
+contextlib.AbstractAsyncContextManager[T]
+-----------------------------------------
 
 .. code-block:: python
 
    def __aenter__(self) -> Awaitable[T]
    def __aexit__(self,
-                 exc_type: Optional[Type[BaseException]],
-                 exc_value: Optional[BaseException],
-                 traceback: Optional[TracebackType]) -> Awaitable[Optional[bool]]
+                 exc_type: type[BaseException] | None,
+                 exc_value: BaseException | None,
+                 traceback: TracebackType | None) -> Awaitable[bool | None]
 
-See also :py:class:`~typing.AsyncContextManager`.
+See also :py:class:`~contextlib.AbstractAsyncContextManager`.
diff --git a/docs/source/runtime_troubles.rst b/docs/source/runtime_troubles.rst
index 66ab7b3a84c7..d039db30f3fa 100644
--- a/docs/source/runtime_troubles.rst
+++ b/docs/source/runtime_troubles.rst
@@ -21,8 +21,9 @@ problems you may encounter.
 String literal types and type comments
 --------------------------------------
 
-Mypy allows you to add type annotations using ``# type:`` type comments.
-For example:
+Mypy lets you add type annotations using the (now deprecated) ``# type:``
+type comment syntax. These were required with Python versions older than 3.6,
+since they didn't support type annotations on variables. Example:
 
 .. code-block:: python
 
@@ -69,7 +70,7 @@ Future annotations import (PEP 563)
 -----------------------------------
 
 Many of the issues described here are caused by Python trying to evaluate
-annotations. Future Python versions (potentially Python 3.12) will by default no
+annotations. Future Python versions (potentially Python 3.14) will by default no
 longer attempt to evaluate function and variable annotations. This behaviour is
 made available in Python 3.7 and later through the use of
 ``from __future__ import annotations``.
@@ -84,7 +85,7 @@ required to be valid Python syntax. For more details, see :pep:`563`.
     still require string literals or result in errors, typically involving use
     of forward references or generics in:
 
-    * :ref:`type aliases <type-aliases>`;
+    * :ref:`type aliases <type-aliases>` not defined using the ``type`` statement;
     * :ref:`type narrowing <type-narrowing>`;
     * type definitions (see :py:class:`~typing.TypeVar`, :py:class:`~typing.NewType`, :py:class:`~typing.NamedTuple`);
     * base classes.
@@ -93,6 +94,7 @@ required to be valid Python syntax. For more details, see :pep:`563`.
 
         # base class example
         from __future__ import annotations
+
         class A(tuple['B', 'C']): ... # String literal types needed here
         class B: ...
         class C: ...
@@ -244,7 +246,8 @@ complicated and you need to use :ref:`typing.TYPE_CHECKING
    task_queue: Tasks
    reveal_type(task_queue.get())  # Reveals str
 
-If your subclass is also generic, you can use the following:
+If your subclass is also generic, you can use the following (using the
+legacy syntax for generic classes):
 
 .. code-block:: python
 
@@ -262,9 +265,11 @@ If your subclass is also generic, you can use the following:
    task_queue: MyQueue[str]
    reveal_type(task_queue.get())  # Reveals str
 
-In Python 3.9, we can just inherit directly from ``Queue[str]`` or ``Queue[T]``
+In Python 3.9 and later, we can just inherit directly from ``Queue[str]`` or ``Queue[T]``
 since its :py:class:`queue.Queue` implements :py:meth:`~object.__class_getitem__`, so
-the class object can be subscripted at runtime without issue.
+the class object can be subscripted at runtime. You may still encounter issues (even if
+you use a recent Python version) when subclassing generic classes defined in third-party
+libraries if types are generic only in stubs.
 
 Using types defined in stubs but not at runtime
 -----------------------------------------------
@@ -315,8 +320,8 @@ notes at :ref:`future annotations import<future-annotations>`.
 Using X | Y syntax for Unions
 -----------------------------
 
-Starting with Python 3.10 (:pep:`604`), you can spell union types as ``x: int |
-str``, instead of ``x: typing.Union[int, str]``.
+Starting with Python 3.10 (:pep:`604`), you can spell union types as
+``x: int | str``, instead of ``x: typing.Union[int, str]``.
 
 There is limited support for using this syntax in Python 3.7 and later as well:
 if you use ``from __future__ import annotations``, mypy will understand this
diff --git a/docs/source/type_inference_and_annotations.rst b/docs/source/type_inference_and_annotations.rst
index 6adb4e651224..318ca4cd9160 100644
--- a/docs/source/type_inference_and_annotations.rst
+++ b/docs/source/type_inference_and_annotations.rst
@@ -41,12 +41,10 @@ variable type annotation:
 
 .. code-block:: python
 
-   from typing import Union
-
-   x: Union[int, str] = 1
+   x: int | str = 1
 
 Without the type annotation, the type of ``x`` would be just ``int``. We
-use an annotation to give it a more general type ``Union[int, str]`` (this
+use an annotation to give it a more general type ``int | str`` (this
 type means that the value can be either an ``int`` or a ``str``).
 
 The best way to think about this is that the type annotation sets the type of
@@ -55,8 +53,8 @@ about the following code:
 
 .. code-block:: python
 
-   x: Union[int, str] = 1.1  # error: Incompatible types in assignment
-                             # (expression has type "float", variable has type "Union[int, str]")
+   x: int | str = 1.1  # error: Incompatible types in assignment
+                       # (expression has type "float", variable has type "int | str")
 
 .. note::
 
diff --git a/docs/source/type_narrowing.rst b/docs/source/type_narrowing.rst
index d698f35c44bc..231a7edccfe7 100644
--- a/docs/source/type_narrowing.rst
+++ b/docs/source/type_narrowing.rst
@@ -114,7 +114,7 @@ So, we know what ``callable()`` will return. For example:
 
 .. code-block:: python
 
-  from typing import Callable
+  from collections.abc import Callable
 
   x: Callable[[], int]
 
@@ -123,14 +123,14 @@ So, we know what ``callable()`` will return. For example:
   else:
       ...  # Will never be executed and will raise error with `--warn-unreachable`
 
-``callable`` function can even split ``Union`` type
-for callable and non-callable parts:
+The ``callable`` function can even split union types into
+callable and non-callable parts:
 
 .. code-block:: python
 
-  from typing import Callable, Union
+  from collections.abc import Callable
 
-  x: Union[int, Callable[[], int]]
+  x: int | Callable[[], int]
 
   if callable(x):
       reveal_type(x)  # N: Revealed type is "def () -> builtins.int"
@@ -255,16 +255,13 @@ to the type specified as the first type parameter (``list[str]``).
 Generic TypeGuards
 ~~~~~~~~~~~~~~~~~~
 
-``TypeGuard`` can also work with generic types:
+``TypeGuard`` can also work with generic types (Python 3.12 syntax):
 
 .. code-block:: python
 
-  from typing import TypeVar
   from typing import TypeGuard  # use `typing_extensions` for `python<3.10`
 
-  _T = TypeVar("_T")
-
-  def is_two_element_tuple(val: tuple[_T, ...]) -> TypeGuard[tuple[_T, _T]]:
+  def is_two_element_tuple[T](val: tuple[T, ...]) -> TypeGuard[tuple[T, T]]:
       return len(val) == 2
 
   def func(names: tuple[str, ...]):
@@ -276,16 +273,13 @@ Generic TypeGuards
 TypeGuards with parameters
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Type guard functions can accept extra arguments:
+Type guard functions can accept extra arguments (Python 3.12 syntax):
 
 .. code-block:: python
 
-  from typing import Type, TypeVar
   from typing import TypeGuard  # use `typing_extensions` for `python<3.10`
 
-  _T = TypeVar("_T")
-
-  def is_set_of(val: set[Any], type: Type[_T]) -> TypeGuard[set[_T]]:
+  def is_set_of[T](val: set[Any], type: type[T]) -> TypeGuard[set[T]]:
       return all(isinstance(x, type) for x in val)
 
   items: set[Any]
diff --git a/docs/source/typed_dict.rst b/docs/source/typed_dict.rst
index c379b5449eae..e69b3895c668 100644
--- a/docs/source/typed_dict.rst
+++ b/docs/source/typed_dict.rst
@@ -89,7 +89,7 @@ A ``TypedDict`` object is not a subtype of the regular ``dict[...]``
 type (and vice versa), since :py:class:`dict` allows arbitrary keys to be
 added and removed, unlike ``TypedDict``. However, any ``TypedDict`` object is
 a subtype of (that is, compatible with) ``Mapping[str, object]``, since
-:py:class:`~typing.Mapping` only provides read-only access to the dictionary items:
+:py:class:`~collections.abc.Mapping` only provides read-only access to the dictionary items:
 
 .. code-block:: python
 
@@ -158,7 +158,7 @@ You must use string literals as keys when calling most of the methods,
 as otherwise mypy won't be able to check that the key is valid. List
 of supported operations:
 
-* Anything included in :py:class:`~typing.Mapping`:
+* Anything included in :py:class:`~collections.abc.Mapping`:
 
   * ``d[key]``
   * ``key in d``
diff --git a/mypy/checker.py b/mypy/checker.py
index db65660bbfbd..9c4f4ce88690 100644
--- a/mypy/checker.py
+++ b/mypy/checker.py
@@ -5651,7 +5651,16 @@ def _is_truthy_type(self, t: ProperType) -> bool:
             )
         )
 
-    def _check_for_truthy_type(self, t: Type, expr: Expression) -> None:
+    def check_for_truthy_type(self, t: Type, expr: Expression) -> None:
+        """
+        Check if a type can have a truthy value.
+
+        Used in checks like::
+
+            if x: # <---
+
+            not x  # <---
+        """
         if not state.strict_optional:
             return  # if everything can be None, all bets are off
 
@@ -6145,7 +6154,7 @@ def has_no_custom_eq_checks(t: Type) -> bool:
         if in_boolean_context:
             # We don't check `:=` values in expressions like `(a := A())`,
             # because they produce two error messages.
-            self._check_for_truthy_type(original_vartype, node)
+            self.check_for_truthy_type(original_vartype, node)
         vartype = try_expanding_sum_type_to_union(original_vartype, "builtins.bool")
 
         if_type = true_only(vartype)
diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py
index 9dee743ad406..55c42335744d 100644
--- a/mypy/checkexpr.py
+++ b/mypy/checkexpr.py
@@ -1756,7 +1756,11 @@ def check_callable_call(
                 )
 
         param_spec = callee.param_spec()
-        if param_spec is not None and arg_kinds == [ARG_STAR, ARG_STAR2]:
+        if (
+            param_spec is not None
+            and arg_kinds == [ARG_STAR, ARG_STAR2]
+            and len(formal_to_actual) == 2
+        ):
             arg1 = self.accept(args[0])
             arg2 = self.accept(args[1])
             if (
@@ -2362,6 +2366,9 @@ def check_argument_count(
                 # Positional argument when expecting a keyword argument.
                 self.msg.too_many_positional_arguments(callee, context)
                 ok = False
+            elif callee.param_spec() is not None and not formal_to_actual[i]:
+                self.msg.too_few_arguments(callee, context, actual_names)
+                ok = False
         return ok
 
     def check_for_extra_actual_arguments(
@@ -2763,9 +2770,9 @@ def plausible_overload_call_targets(
     ) -> list[CallableType]:
         """Returns all overload call targets that having matching argument counts.
 
-        If the given args contains a star-arg (*arg or **kwarg argument), this method
-        will ensure all star-arg overloads appear at the start of the list, instead
-        of their usual location.
+        If the given args contains a star-arg (*arg or **kwarg argument, including
+        ParamSpec), this method will ensure all star-arg overloads appear at the start
+        of the list, instead of their usual location.
 
         The only exception is if the starred argument is something like a Tuple or a
         NamedTuple, which has a definitive "shape". If so, we don't move the corresponding
@@ -2793,9 +2800,13 @@ def has_shape(typ: Type) -> bool:
             formal_to_actual = map_actuals_to_formals(
                 arg_kinds, arg_names, typ.arg_kinds, typ.arg_names, lambda i: arg_types[i]
             )
-
             with self.msg.filter_errors():
-                if self.check_argument_count(
+                if typ.param_spec() is not None:
+                    # ParamSpec can be expanded in a lot of different ways. We may try
+                    # to expand it here instead, but picking an impossible overload
+                    # is safe: it will be filtered out later.
+                    star_matches.append(typ)
+                elif self.check_argument_count(
                     typ, arg_types, arg_kinds, arg_names, formal_to_actual, None
                 ):
                     if args_have_var_arg and typ.is_var_arg:
@@ -4256,6 +4267,7 @@ def visit_unary_expr(self, e: UnaryExpr) -> Type:
         op = e.op
         if op == "not":
             result: Type = self.bool_type()
+            self.chk.check_for_truthy_type(operand_type, e.expr)
         else:
             method = operators.unary_op_methods[op]
             result, method_type = self.check_method_call_by_name(method, operand_type, [], [], e)
diff --git a/mypy/errorcodes.py b/mypy/errorcodes.py
index 6e8763264ddd..ad061b161af1 100644
--- a/mypy/errorcodes.py
+++ b/mypy/errorcodes.py
@@ -273,6 +273,14 @@ def __hash__(self) -> int:
 # This is a catch-all for remaining uncategorized errors.
 MISC: Final[ErrorCode] = ErrorCode("misc", "Miscellaneous other checks", "General")
 
+OVERLOAD_CANNOT_MATCH: Final[ErrorCode] = ErrorCode(
+    "overload-cannot-match",
+    "Warn if an @overload signature can never be matched",
+    "General",
+    sub_code_of=MISC,
+)
+
+
 OVERLOAD_OVERLAP: Final[ErrorCode] = ErrorCode(
     "overload-overlap",
     "Warn if multiple @overload variants overlap in unsafe ways",
diff --git a/mypy/exprtotype.py b/mypy/exprtotype.py
index 92316d11926d..c7df851668be 100644
--- a/mypy/exprtotype.py
+++ b/mypy/exprtotype.py
@@ -2,12 +2,15 @@
 
 from __future__ import annotations
 
+from typing import Callable
+
 from mypy.fastparse import parse_type_string
 from mypy.nodes import (
     MISSING_FALLBACK,
     BytesExpr,
     CallExpr,
     ComplexExpr,
+    Context,
     DictExpr,
     EllipsisExpr,
     Expression,
@@ -21,6 +24,7 @@
     RefExpr,
     StarExpr,
     StrExpr,
+    SymbolTableNode,
     TupleExpr,
     UnaryExpr,
     get_member_expr_fullname,
@@ -63,12 +67,16 @@ def expr_to_unanalyzed_type(
     allow_new_syntax: bool = False,
     _parent: Expression | None = None,
     allow_unpack: bool = False,
+    lookup_qualified: Callable[[str, Context], SymbolTableNode | None] | None = None,
 ) -> ProperType:
     """Translate an expression to the corresponding type.
 
     The result is not semantically analyzed. It can be UnboundType or TypeList.
     Raise TypeTranslationError if the expression cannot represent a type.
 
+    If lookup_qualified is not provided, the expression is expected to be semantically
+    analyzed.
+
     If allow_new_syntax is True, allow all type syntax independent of the target
     Python version (used in stubs).
 
@@ -101,19 +109,26 @@ def expr_to_unanalyzed_type(
             else:
                 args = [expr.index]
 
-            if isinstance(expr.base, RefExpr) and expr.base.fullname in ANNOTATED_TYPE_NAMES:
-                # TODO: this is not the optimal solution as we are basically getting rid
-                # of the Annotation definition and only returning the type information,
-                # losing all the annotations.
+            if isinstance(expr.base, RefExpr):
+                # Check if the type is Annotated[...]. For this we need the fullname,
+                # which must be looked up if the expression hasn't been semantically analyzed.
+                base_fullname = None
+                if lookup_qualified is not None:
+                    sym = lookup_qualified(base.name, expr)
+                    if sym and sym.node:
+                        base_fullname = sym.node.fullname
+                else:
+                    base_fullname = expr.base.fullname
 
-                return expr_to_unanalyzed_type(args[0], options, allow_new_syntax, expr)
-            else:
-                base.args = tuple(
-                    expr_to_unanalyzed_type(
-                        arg, options, allow_new_syntax, expr, allow_unpack=True
-                    )
-                    for arg in args
-                )
+                if base_fullname is not None and base_fullname in ANNOTATED_TYPE_NAMES:
+                    # TODO: this is not the optimal solution as we are basically getting rid
+                    # of the Annotation definition and only returning the type information,
+                    # losing all the annotations.
+                    return expr_to_unanalyzed_type(args[0], options, allow_new_syntax, expr)
+            base.args = tuple(
+                expr_to_unanalyzed_type(arg, options, allow_new_syntax, expr, allow_unpack=True)
+                for arg in args
+            )
             if not base.args:
                 base.empty_tuple_index = True
             return base
diff --git a/mypy/fastparse.py b/mypy/fastparse.py
index abcce74c6064..18858b0fa0b8 100644
--- a/mypy/fastparse.py
+++ b/mypy/fastparse.py
@@ -92,7 +92,7 @@
     YieldFromExpr,
     check_arg_names,
 )
-from mypy.options import NEW_GENERIC_SYNTAX, Options
+from mypy.options import Options
 from mypy.patterns import (
     AsPattern,
     ClassPattern,
@@ -965,19 +965,7 @@ def do_func_def(
                 return_type = AnyType(TypeOfAny.from_error)
         else:
             if sys.version_info >= (3, 12) and n.type_params:
-                if NEW_GENERIC_SYNTAX in self.options.enable_incomplete_feature:
-                    explicit_type_params = self.translate_type_params(n.type_params)
-                else:
-                    self.fail(
-                        ErrorMessage(
-                            "PEP 695 generics are not yet supported. "
-                            "Use --enable-incomplete-feature=NewGenericSyntax for experimental support",
-                            code=codes.VALID_TYPE,
-                        ),
-                        n.type_params[0].lineno,
-                        n.type_params[0].col_offset,
-                        blocker=False,
-                    )
+                explicit_type_params = self.translate_type_params(n.type_params)
 
             arg_types = [a.type_annotation for a in args]
             return_type = TypeConverter(
@@ -1157,19 +1145,7 @@ def visit_ClassDef(self, n: ast3.ClassDef) -> ClassDef:
         explicit_type_params: list[TypeParam] | None = None
 
         if sys.version_info >= (3, 12) and n.type_params:
-            if NEW_GENERIC_SYNTAX in self.options.enable_incomplete_feature:
-                explicit_type_params = self.translate_type_params(n.type_params)
-            else:
-                self.fail(
-                    ErrorMessage(
-                        "PEP 695 generics are not yet supported. "
-                        "Use --enable-incomplete-feature=NewGenericSyntax for experimental support",
-                        code=codes.VALID_TYPE,
-                    ),
-                    n.type_params[0].lineno,
-                    n.type_params[0].col_offset,
-                    blocker=False,
-                )
+            explicit_type_params = self.translate_type_params(n.type_params)
 
         cdef = ClassDef(
             n.name,
@@ -1843,31 +1819,17 @@ def validate_type_alias(self, n: ast_TypeAlias) -> None:
     # TypeAlias(identifier name, type_param* type_params, expr value)
     def visit_TypeAlias(self, n: ast_TypeAlias) -> TypeAliasStmt | AssignmentStmt:
         node: TypeAliasStmt | AssignmentStmt
-        if NEW_GENERIC_SYNTAX in self.options.enable_incomplete_feature:
-            type_params = self.translate_type_params(n.type_params)
-            self.validate_type_alias(n)
-            value = self.visit(n.value)
-            # Since the value is evaluated lazily, wrap the value inside a lambda.
-            # This helps mypyc.
-            ret = ReturnStmt(value)
-            self.set_line(ret, n.value)
-            value_func = LambdaExpr(body=Block([ret]))
-            self.set_line(value_func, n.value)
-            node = TypeAliasStmt(self.visit_Name(n.name), type_params, value_func)
-            return self.set_line(node, n)
-        else:
-            self.fail(
-                ErrorMessage(
-                    "PEP 695 type aliases are not yet supported. "
-                    "Use --enable-incomplete-feature=NewGenericSyntax for experimental support",
-                    code=codes.VALID_TYPE,
-                ),
-                n.lineno,
-                n.col_offset,
-                blocker=False,
-            )
-            node = AssignmentStmt([NameExpr(n.name.id)], self.visit(n.value))
-            return self.set_line(node, n)
+        type_params = self.translate_type_params(n.type_params)
+        self.validate_type_alias(n)
+        value = self.visit(n.value)
+        # Since the value is evaluated lazily, wrap the value inside a lambda.
+        # This helps mypyc.
+        ret = ReturnStmt(value)
+        self.set_line(ret, n.value)
+        value_func = LambdaExpr(body=Block([ret]))
+        self.set_line(value_func, n.value)
+        node = TypeAliasStmt(self.visit_Name(n.name), type_params, value_func)
+        return self.set_line(node, n)
 
 
 class TypeConverter:
diff --git a/mypy/messages.py b/mypy/messages.py
index 62846c536f3d..6567d9d96d0b 100644
--- a/mypy/messages.py
+++ b/mypy/messages.py
@@ -1653,6 +1653,7 @@ def overloaded_signature_will_never_match(
                 index1=index1, index2=index2
             ),
             context,
+            code=codes.OVERLOAD_CANNOT_MATCH,
         )
 
     def overloaded_signatures_typevar_specific(self, index: int, context: Context) -> None:
@@ -2941,9 +2942,9 @@ def [T <: int] f(self, x: int, y: T) -> None
         for tvar in tp.variables:
             if isinstance(tvar, TypeVarType):
                 upper_bound = get_proper_type(tvar.upper_bound)
-                if (
+                if not (
                     isinstance(upper_bound, Instance)
-                    and upper_bound.type.fullname != "builtins.object"
+                    and upper_bound.type.fullname == "builtins.object"
                 ):
                     tvars.append(f"{tvar.name}: {format_type_bare(upper_bound, options)}")
                 elif tvar.values:
diff --git a/mypy/options.py b/mypy/options.py
index 5e64d5e40035..56bd92957b41 100644
--- a/mypy/options.py
+++ b/mypy/options.py
@@ -75,8 +75,8 @@ class BuildType:
 PRECISE_TUPLE_TYPES: Final = "PreciseTupleTypes"
 NEW_GENERIC_SYNTAX: Final = "NewGenericSyntax"
 INLINE_TYPEDDICT: Final = "InlineTypedDict"
-INCOMPLETE_FEATURES: Final = frozenset((PRECISE_TUPLE_TYPES, NEW_GENERIC_SYNTAX, INLINE_TYPEDDICT))
-COMPLETE_FEATURES: Final = frozenset((TYPE_VAR_TUPLE, UNPACK))
+INCOMPLETE_FEATURES: Final = frozenset((PRECISE_TUPLE_TYPES, INLINE_TYPEDDICT))
+COMPLETE_FEATURES: Final = frozenset((TYPE_VAR_TUPLE, UNPACK, NEW_GENERIC_SYNTAX))
 
 
 class Options:
diff --git a/mypy/report.py b/mypy/report.py
index 764cfec7799a..73942b6c5ae3 100644
--- a/mypy/report.py
+++ b/mypy/report.py
@@ -689,6 +689,8 @@ def on_finish(self) -> None:
             self.root_package.covered_lines, self.root_package.total_lines
         )
         self.root.attrib["branch-rate"] = "0"
+        self.root.attrib["lines-covered"] = str(self.root_package.covered_lines)
+        self.root.attrib["lines-valid"] = str(self.root_package.total_lines)
         sources = etree.SubElement(self.root, "sources")
         source_element = etree.SubElement(sources, "source")
         source_element.text = os.getcwd()
diff --git a/mypy/semanal.py b/mypy/semanal.py
index 782985e3fbab..0b654d6b145f 100644
--- a/mypy/semanal.py
+++ b/mypy/semanal.py
@@ -824,6 +824,11 @@ def file_context(
             self.num_incomplete_refs = 0
 
             if active_type:
+                enclosing_fullname = active_type.fullname.rsplit(".", 1)[0]
+                if "." in enclosing_fullname:
+                    enclosing_node = self.lookup_fully_qualified_or_none(enclosing_fullname)
+                    if enclosing_node and isinstance(enclosing_node.node, TypeInfo):
+                        self._type = enclosing_node.node
                 self.push_type_args(active_type.defn.type_args, active_type.defn)
                 self.incomplete_type_stack.append(False)
                 scope.enter_class(active_type)
@@ -1819,6 +1824,8 @@ def analyze_class(self, defn: ClassDef) -> None:
             defn, bases, context=defn
         )
 
+        self.check_type_alias_bases(bases)
+
         for tvd in tvar_defs:
             if isinstance(tvd, TypeVarType) and any(
                 has_placeholder(t) for t in [tvd.upper_bound] + tvd.values
@@ -1890,6 +1897,19 @@ def analyze_class(self, defn: ClassDef) -> None:
 
             self.analyze_class_body_common(defn)
 
+    def check_type_alias_bases(self, bases: list[Expression]) -> None:
+        for base in bases:
+            if isinstance(base, IndexExpr):
+                base = base.base
+            if (
+                isinstance(base, RefExpr)
+                and isinstance(base.node, TypeAlias)
+                and base.node.python_3_12_type_alias
+            ):
+                self.fail(
+                    'Type alias defined using "type" statement not valid as base class', base
+                )
+
     def setup_type_vars(self, defn: ClassDef, tvar_defs: list[TypeVarLikeType]) -> None:
         defn.type_vars = tvar_defs
         defn.info.type_vars = []
@@ -3744,7 +3764,9 @@ def analyze_alias(
         dynamic = bool(self.function_stack and self.function_stack[-1].is_dynamic())
         global_scope = not self.type and not self.function_stack
         try:
-            typ = expr_to_unanalyzed_type(rvalue, self.options, self.is_stub_file)
+            typ = expr_to_unanalyzed_type(
+                rvalue, self.options, self.is_stub_file, lookup_qualified=self.lookup_qualified
+            )
         except TypeTranslationError:
             self.fail(
                 "Invalid type alias: expression is not a valid type", rvalue, code=codes.VALID_TYPE
@@ -5904,9 +5926,8 @@ def analyze_type_application_args(self, expr: IndexExpr) -> list[Type] | None:
 
         if has_param_spec and num_args == 1 and types:
             first_arg = get_proper_type(types[0])
-            if not (
-                len(types) == 1 and isinstance(first_arg, (Parameters, ParamSpecType, AnyType))
-            ):
+            single_any = len(types) == 1 and isinstance(first_arg, AnyType)
+            if not (single_any or any(isinstance(t, (Parameters, ParamSpecType)) for t in types)):
                 types = [Parameters(types, [ARG_POS] * len(types), [None] * len(types))]
 
         return types
@@ -6948,6 +6969,7 @@ def name_not_defined(self, name: str, ctx: Context, namespace: str | None = None
             namespace is None
             and self.type
             and not self.is_func_scope()
+            and self.incomplete_type_stack
             and self.incomplete_type_stack[-1]
             and not self.final_iteration
         ):
diff --git a/mypy/stubgen.py b/mypy/stubgen.py
index 14417f55545e..02c0c1e58ab5 100755
--- a/mypy/stubgen.py
+++ b/mypy/stubgen.py
@@ -588,8 +588,8 @@ def _get_func_return(self, o: FuncDef, ctx: FunctionContext) -> str | None:
         if has_yield_expression(o) or has_yield_from_expression(o):
             generator_name = self.add_name("collections.abc.Generator")
             yield_name = "None"
-            send_name = "None"
-            return_name = "None"
+            send_name: str | None = None
+            return_name: str | None = None
             if has_yield_from_expression(o):
                 yield_name = send_name = self.add_name("_typeshed.Incomplete")
             else:
@@ -600,7 +600,14 @@ def _get_func_return(self, o: FuncDef, ctx: FunctionContext) -> str | None:
                         send_name = self.add_name("_typeshed.Incomplete")
             if has_return_statement(o):
                 return_name = self.add_name("_typeshed.Incomplete")
-            return f"{generator_name}[{yield_name}, {send_name}, {return_name}]"
+            if return_name is not None:
+                if send_name is None:
+                    send_name = "None"
+                return f"{generator_name}[{yield_name}, {send_name}, {return_name}]"
+            elif send_name is not None:
+                return f"{generator_name}[{yield_name}, {send_name}]"
+            else:
+                return f"{generator_name}[{yield_name}]"
         if not has_return_statement(o) and o.abstract_status == NOT_ABSTRACT:
             return "None"
         return None
diff --git a/mypy/subtypes.py b/mypy/subtypes.py
index 649cbae4c831..c76b3569fdd4 100644
--- a/mypy/subtypes.py
+++ b/mypy/subtypes.py
@@ -2004,19 +2004,36 @@ def infer_variance(info: TypeInfo, i: int) -> bool:
         tvar = info.defn.type_vars[i]
         self_type = fill_typevars(info)
         for member in all_non_object_members(info):
-            if member in ("__init__", "__new__"):
+            # __mypy-replace is an implementation detail of the dataclass plugin
+            if member in ("__init__", "__new__", "__mypy-replace"):
                 continue
-            node = info[member].node
-            if isinstance(node, Var) and node.type is None:
-                tv.variance = VARIANCE_NOT_READY
-                return False
+
             if isinstance(self_type, TupleType):
                 self_type = mypy.typeops.tuple_fallback(self_type)
-
             flags = get_member_flags(member, self_type)
-            typ = find_member(member, self_type, self_type)
             settable = IS_SETTABLE in flags
+
+            node = info[member].node
+            if isinstance(node, Var):
+                if node.type is None:
+                    tv.variance = VARIANCE_NOT_READY
+                    return False
+                if has_underscore_prefix(member):
+                    # Special case to avoid false positives (and to pass conformance tests)
+                    settable = False
+
+            typ = find_member(member, self_type, self_type)
             if typ:
+                # It's okay for a method in a generic class with a contravariant type
+                # variable to return a generic instance of the class, if it doesn't involve
+                # variance (i.e. values of type variables are propagated). Our normal rules
+                # would disallow this. Replace such return types with 'Any' to allow this.
+                #
+                # This could probably be more lenient (e.g. allow self type be nested, don't
+                # require all type arguments to be identical to self_type), but this will
+                # hopefully cover the vast majority of such cases, including Self.
+                typ = erase_return_self_types(typ, self_type)
+
                 typ2 = expand_type(typ, {tvar.id: object_type})
                 if not is_subtype(typ, typ2):
                     co = False
@@ -2024,6 +2041,15 @@ def infer_variance(info: TypeInfo, i: int) -> bool:
                     contra = False
                     if settable:
                         co = False
+
+        # Infer variance from base classes, in case they have explicit variances
+        for base in info.bases:
+            base2 = expand_type(base, {tvar.id: object_type})
+            if not is_subtype(base, base2):
+                co = False
+            if not is_subtype(base2, base):
+                contra = False
+
         if co:
             v = COVARIANT
         elif contra:
@@ -2036,6 +2062,10 @@ def infer_variance(info: TypeInfo, i: int) -> bool:
     return True
 
 
+def has_underscore_prefix(name: str) -> bool:
+    return name.startswith("_") and not (name.startswith("__") and name.endswith("__"))
+
+
 def infer_class_variances(info: TypeInfo) -> bool:
     if not info.defn.type_args:
         return True
@@ -2046,3 +2076,20 @@ def infer_class_variances(info: TypeInfo) -> bool:
             if not infer_variance(info, i):
                 success = False
     return success
+
+
+def erase_return_self_types(typ: Type, self_type: Instance) -> Type:
+    """If a typ is function-like and returns self_type, replace return type with Any."""
+    proper_type = get_proper_type(typ)
+    if isinstance(proper_type, CallableType):
+        ret = get_proper_type(proper_type.ret_type)
+        if isinstance(ret, Instance) and ret == self_type:
+            return proper_type.copy_modified(ret_type=AnyType(TypeOfAny.implementation_artifact))
+    elif isinstance(proper_type, Overloaded):
+        return Overloaded(
+            [
+                cast(CallableType, erase_return_self_types(it, self_type))
+                for it in proper_type.items
+            ]
+        )
+    return typ
diff --git a/mypy/typeops.py b/mypy/typeops.py
index d22448a715e5..7f530d13d4e2 100644
--- a/mypy/typeops.py
+++ b/mypy/typeops.py
@@ -657,6 +657,10 @@ def false_only(t: Type) -> ProperType:
         new_items = [false_only(item) for item in t.items]
         can_be_false_items = [item for item in new_items if item.can_be_false]
         return make_simplified_union(can_be_false_items, line=t.line, column=t.column)
+    elif isinstance(t, Instance) and t.type.fullname in ("builtins.str", "builtins.bytes"):
+        return LiteralType("", fallback=t)
+    elif isinstance(t, Instance) and t.type.fullname == "builtins.int":
+        return LiteralType(0, fallback=t)
     else:
         ret_type = _get_type_method_ret_type(t, name="__bool__") or _get_type_method_ret_type(
             t, name="__len__"
diff --git a/mypy/typeshed/stdlib/VERSIONS b/mypy/typeshed/stdlib/VERSIONS
index 641f951ce3c0..dfed62f694fc 100644
--- a/mypy/typeshed/stdlib/VERSIONS
+++ b/mypy/typeshed/stdlib/VERSIONS
@@ -41,7 +41,7 @@ _json: 3.0-
 _locale: 3.0-
 _lsprof: 3.0-
 _markupbase: 3.0-
-_msi: 3.0-
+_msi: 3.0-3.12
 _operator: 3.4-
 _osx_support: 3.0-
 _posixsubprocess: 3.2-
@@ -161,6 +161,8 @@ importlib.metadata._meta: 3.10-
 importlib.metadata.diagnose: 3.13-
 importlib.readers: 3.10-
 importlib.resources: 3.7-
+importlib.resources._common: 3.11-
+importlib.resources._functional: 3.13-
 importlib.resources.abc: 3.11-
 importlib.resources.readers: 3.11-
 importlib.resources.simple: 3.11-
diff --git a/mypy/typeshed/stdlib/_curses.pyi b/mypy/typeshed/stdlib/_curses.pyi
index 505637574af1..b68c8925a041 100644
--- a/mypy/typeshed/stdlib/_curses.pyi
+++ b/mypy/typeshed/stdlib/_curses.pyi
@@ -493,7 +493,7 @@ class _CursesWindow:
     def instr(self, y: int, x: int, n: int = ...) -> bytes: ...
     def is_linetouched(self, line: int, /) -> bool: ...
     def is_wintouched(self) -> bool: ...
-    def keypad(self, yes: bool) -> None: ...
+    def keypad(self, yes: bool, /) -> None: ...
     def leaveok(self, yes: bool) -> None: ...
     def move(self, new_y: int, new_x: int) -> None: ...
     def mvderwin(self, y: int, x: int) -> None: ...
diff --git a/mypy/typeshed/stdlib/_locale.pyi b/mypy/typeshed/stdlib/_locale.pyi
index 0825e12034f4..ccce7a0d9d70 100644
--- a/mypy/typeshed/stdlib/_locale.pyi
+++ b/mypy/typeshed/stdlib/_locale.pyi
@@ -1,17 +1,38 @@
 import sys
 from _typeshed import StrPath
-from collections.abc import Mapping
+from typing import Final, Literal, TypedDict, type_check_only
 
-LC_CTYPE: int
-LC_COLLATE: int
-LC_TIME: int
-LC_MONETARY: int
-LC_NUMERIC: int
-LC_ALL: int
-CHAR_MAX: int
+@type_check_only
+class _LocaleConv(TypedDict):
+    decimal_point: str
+    grouping: list[int]
+    thousands_sep: str
+    int_curr_symbol: str
+    currency_symbol: str
+    p_cs_precedes: Literal[0, 1, 127]
+    n_cs_precedes: Literal[0, 1, 127]
+    p_sep_by_space: Literal[0, 1, 127]
+    n_sep_by_space: Literal[0, 1, 127]
+    mon_decimal_point: str
+    frac_digits: int
+    int_frac_digits: int
+    mon_thousands_sep: str
+    mon_grouping: list[int]
+    positive_sign: str
+    negative_sign: str
+    p_sign_posn: Literal[0, 1, 2, 3, 4, 127]
+    n_sign_posn: Literal[0, 1, 2, 3, 4, 127]
+
+LC_CTYPE: Final[int]
+LC_COLLATE: Final[int]
+LC_TIME: Final[int]
+LC_MONETARY: Final[int]
+LC_NUMERIC: Final[int]
+LC_ALL: Final[int]
+CHAR_MAX: Final = 127
 
 def setlocale(category: int, locale: str | None = None, /) -> str: ...
-def localeconv() -> Mapping[str, int | str | list[int]]: ...
+def localeconv() -> _LocaleConv: ...
 
 if sys.version_info >= (3, 11):
     def getencoding() -> str: ...
@@ -25,67 +46,67 @@ def strxfrm(string: str, /) -> str: ...
 if sys.platform != "win32":
     LC_MESSAGES: int
 
-    ABDAY_1: int
-    ABDAY_2: int
-    ABDAY_3: int
-    ABDAY_4: int
-    ABDAY_5: int
-    ABDAY_6: int
-    ABDAY_7: int
+    ABDAY_1: Final[int]
+    ABDAY_2: Final[int]
+    ABDAY_3: Final[int]
+    ABDAY_4: Final[int]
+    ABDAY_5: Final[int]
+    ABDAY_6: Final[int]
+    ABDAY_7: Final[int]
 
-    ABMON_1: int
-    ABMON_2: int
-    ABMON_3: int
-    ABMON_4: int
-    ABMON_5: int
-    ABMON_6: int
-    ABMON_7: int
-    ABMON_8: int
-    ABMON_9: int
-    ABMON_10: int
-    ABMON_11: int
-    ABMON_12: int
+    ABMON_1: Final[int]
+    ABMON_2: Final[int]
+    ABMON_3: Final[int]
+    ABMON_4: Final[int]
+    ABMON_5: Final[int]
+    ABMON_6: Final[int]
+    ABMON_7: Final[int]
+    ABMON_8: Final[int]
+    ABMON_9: Final[int]
+    ABMON_10: Final[int]
+    ABMON_11: Final[int]
+    ABMON_12: Final[int]
 
-    DAY_1: int
-    DAY_2: int
-    DAY_3: int
-    DAY_4: int
-    DAY_5: int
-    DAY_6: int
-    DAY_7: int
+    DAY_1: Final[int]
+    DAY_2: Final[int]
+    DAY_3: Final[int]
+    DAY_4: Final[int]
+    DAY_5: Final[int]
+    DAY_6: Final[int]
+    DAY_7: Final[int]
 
-    ERA: int
-    ERA_D_T_FMT: int
-    ERA_D_FMT: int
-    ERA_T_FMT: int
+    ERA: Final[int]
+    ERA_D_T_FMT: Final[int]
+    ERA_D_FMT: Final[int]
+    ERA_T_FMT: Final[int]
 
-    MON_1: int
-    MON_2: int
-    MON_3: int
-    MON_4: int
-    MON_5: int
-    MON_6: int
-    MON_7: int
-    MON_8: int
-    MON_9: int
-    MON_10: int
-    MON_11: int
-    MON_12: int
+    MON_1: Final[int]
+    MON_2: Final[int]
+    MON_3: Final[int]
+    MON_4: Final[int]
+    MON_5: Final[int]
+    MON_6: Final[int]
+    MON_7: Final[int]
+    MON_8: Final[int]
+    MON_9: Final[int]
+    MON_10: Final[int]
+    MON_11: Final[int]
+    MON_12: Final[int]
 
-    CODESET: int
-    D_T_FMT: int
-    D_FMT: int
-    T_FMT: int
-    T_FMT_AMPM: int
-    AM_STR: int
-    PM_STR: int
+    CODESET: Final[int]
+    D_T_FMT: Final[int]
+    D_FMT: Final[int]
+    T_FMT: Final[int]
+    T_FMT_AMPM: Final[int]
+    AM_STR: Final[int]
+    PM_STR: Final[int]
 
-    RADIXCHAR: int
-    THOUSEP: int
-    YESEXPR: int
-    NOEXPR: int
-    CRNCYSTR: int
-    ALT_DIGITS: int
+    RADIXCHAR: Final[int]
+    THOUSEP: Final[int]
+    YESEXPR: Final[int]
+    NOEXPR: Final[int]
+    CRNCYSTR: Final[int]
+    ALT_DIGITS: Final[int]
 
     def nl_langinfo(key: int, /) -> str: ...
 
diff --git a/mypy/typeshed/stdlib/_winapi.pyi b/mypy/typeshed/stdlib/_winapi.pyi
index 62ea124045cc..0f71a0687748 100644
--- a/mypy/typeshed/stdlib/_winapi.pyi
+++ b/mypy/typeshed/stdlib/_winapi.pyi
@@ -99,6 +99,20 @@ if sys.platform == "win32":
     SEC_RESERVE: Final = 0x4000000
     SEC_WRITECOMBINE: Final = 0x40000000
 
+    if sys.version_info >= (3, 13):
+        STARTF_FORCEOFFFEEDBACK: Final = 0x80
+        STARTF_FORCEONFEEDBACK: Final = 0x40
+        STARTF_PREVENTPINNING: Final = 0x2000
+        STARTF_RUNFULLSCREEN: Final = 0x20
+        STARTF_TITLEISAPPID: Final = 0x1000
+        STARTF_TITLEISLINKNAME: Final = 0x800
+        STARTF_UNTRUSTEDSOURCE: Final = 0x8000
+        STARTF_USECOUNTCHARS: Final = 0x8
+        STARTF_USEFILLATTRIBUTE: Final = 0x10
+        STARTF_USEHOTKEY: Final = 0x200
+        STARTF_USEPOSITION: Final = 0x4
+        STARTF_USESIZE: Final = 0x2
+
     STARTF_USESHOWWINDOW: Final = 0x1
     STARTF_USESTDHANDLES: Final = 0x100
 
@@ -250,6 +264,20 @@ if sys.platform == "win32":
         def cancel(self) -> None: ...
         def getbuffer(self) -> bytes | None: ...
 
+    if sys.version_info >= (3, 13):
+        def BatchedWaitForMultipleObjects(
+            handle_seq: Sequence[int], wait_all: bool, milliseconds: int = 0xFFFFFFFF
+        ) -> list[int]: ...
+        def CreateEventW(security_attributes: int, manual_reset: bool, initial_state: bool, name: str | None) -> int: ...
+        def CreateMutexW(security_attributes: int, initial_owner: bool, name: str) -> int: ...
+        def GetLongPathName(path: str) -> str: ...
+        def GetShortPathName(path: str) -> str: ...
+        def OpenEventW(desired_access: int, inherit_handle: bool, name: str) -> int: ...
+        def OpenMutexW(desired_access: int, inherit_handle: bool, name: str) -> int: ...
+        def ReleaseMutex(mutex: int) -> None: ...
+        def ResetEvent(event: int) -> None: ...
+        def SetEvent(event: int) -> None: ...
+
     if sys.version_info >= (3, 12):
         def CopyFile2(existing_file_name: str, new_file_name: str, flags: int, progress_routine: int | None = None) -> int: ...
         def NeedCurrentDirectoryForExePath(exe_name: str, /) -> bool: ...
diff --git a/mypy/typeshed/stdlib/builtins.pyi b/mypy/typeshed/stdlib/builtins.pyi
index a6065cc6777f..0999fb1d6c36 100644
--- a/mypy/typeshed/stdlib/builtins.pyi
+++ b/mypy/typeshed/stdlib/builtins.pyi
@@ -1,3 +1,4 @@
+# ruff: noqa: PYI036 # This is the module declaring BaseException
 import _ast
 import _typeshed
 import sys
diff --git a/mypy/typeshed/stdlib/codecs.pyi b/mypy/typeshed/stdlib/codecs.pyi
index 9bc098dbc6d7..a41df9752d33 100644
--- a/mypy/typeshed/stdlib/codecs.pyi
+++ b/mypy/typeshed/stdlib/codecs.pyi
@@ -80,7 +80,7 @@ class _Encoder(Protocol):
     def __call__(self, input: str, errors: str = ..., /) -> tuple[bytes, int]: ...  # signature of Codec().encode
 
 class _Decoder(Protocol):
-    def __call__(self, input: bytes, errors: str = ..., /) -> tuple[str, int]: ...  # signature of Codec().decode
+    def __call__(self, input: ReadableBuffer, errors: str = ..., /) -> tuple[str, int]: ...  # signature of Codec().decode
 
 class _StreamReader(Protocol):
     def __call__(self, stream: _ReadableStream, errors: str = ..., /) -> StreamReader: ...
diff --git a/mypy/typeshed/stdlib/copy.pyi b/mypy/typeshed/stdlib/copy.pyi
index 020ce6c31b58..2cceec6a2250 100644
--- a/mypy/typeshed/stdlib/copy.pyi
+++ b/mypy/typeshed/stdlib/copy.pyi
@@ -1,16 +1,15 @@
 import sys
 from typing import Any, Protocol, TypeVar
-from typing_extensions import ParamSpec, Self
+from typing_extensions import Self
 
 __all__ = ["Error", "copy", "deepcopy"]
 
 _T = TypeVar("_T")
-_SR = TypeVar("_SR", bound=_SupportsReplace[Any])
-_P = ParamSpec("_P")
+_SR = TypeVar("_SR", bound=_SupportsReplace)
 
-class _SupportsReplace(Protocol[_P]):
+class _SupportsReplace(Protocol):
     # In reality doesn't support args, but there's no other great way to express this.
-    def __replace__(self, *args: _P.args, **kwargs: _P.kwargs) -> Self: ...
+    def __replace__(self, *args: Any, **kwargs: Any) -> Self: ...
 
 # None in CPython but non-None in Jython
 PyStringMap: Any
diff --git a/mypy/typeshed/stdlib/distutils/dist.pyi b/mypy/typeshed/stdlib/distutils/dist.pyi
index 7013167dddbf..75fc7dbb388d 100644
--- a/mypy/typeshed/stdlib/distutils/dist.pyi
+++ b/mypy/typeshed/stdlib/distutils/dist.pyi
@@ -270,7 +270,7 @@ class Distribution:
     def has_data_files(self) -> bool: ...
     def is_pure(self) -> bool: ...
 
-    # Getter methods generated in __init__
+    # Default getter methods generated in __init__ from self.metadata._METHOD_BASENAMES
     def get_name(self) -> str: ...
     def get_version(self) -> str: ...
     def get_fullname(self) -> str: ...
@@ -292,3 +292,26 @@ class Distribution:
     def get_requires(self) -> list[str]: ...
     def get_provides(self) -> list[str]: ...
     def get_obsoletes(self) -> list[str]: ...
+
+    # Default attributes generated in __init__ from self.display_option_names
+    help_commands: bool | Literal[0]
+    name: str | Literal[0]
+    version: str | Literal[0]
+    fullname: str | Literal[0]
+    author: str | Literal[0]
+    author_email: str | Literal[0]
+    maintainer: str | Literal[0]
+    maintainer_email: str | Literal[0]
+    contact: str | Literal[0]
+    contact_email: str | Literal[0]
+    url: str | Literal[0]
+    license: str | Literal[0]
+    licence: str | Literal[0]
+    description: str | Literal[0]
+    long_description: str | Literal[0]
+    platforms: str | list[str] | Literal[0]
+    classifiers: str | list[str] | Literal[0]
+    keywords: str | list[str] | Literal[0]
+    provides: list[str] | Literal[0]
+    requires: list[str] | Literal[0]
+    obsoletes: list[str] | Literal[0]
diff --git a/mypy/typeshed/stdlib/doctest.pyi b/mypy/typeshed/stdlib/doctest.pyi
index 7e334ef0c504..4380083027a6 100644
--- a/mypy/typeshed/stdlib/doctest.pyi
+++ b/mypy/typeshed/stdlib/doctest.pyi
@@ -1,9 +1,10 @@
+import sys
 import types
 import unittest
 from _typeshed import ExcInfo
 from collections.abc import Callable
-from typing import Any, NamedTuple
-from typing_extensions import TypeAlias
+from typing import Any, ClassVar, NamedTuple
+from typing_extensions import Self, TypeAlias
 
 __all__ = [
     "register_optionflag",
@@ -41,9 +42,22 @@ __all__ = [
     "debug",
 ]
 
-class TestResults(NamedTuple):
-    failed: int
-    attempted: int
+# MyPy errors on conditionals within named tuples.
+
+if sys.version_info >= (3, 13):
+    class TestResults(NamedTuple):
+        def __new__(cls, failed: int, attempted: int, *, skipped: int = 0) -> Self: ...  # type: ignore[misc]
+        skipped: int
+        failed: int
+        attempted: int
+        _fields: ClassVar = ("failed", "attempted")  # type: ignore[misc]
+        __match_args__ = ("failed", "attempted")  # type: ignore[misc]
+        __doc__: None  # type: ignore[misc]
+
+else:
+    class TestResults(NamedTuple):
+        failed: int
+        attempted: int
 
 OPTIONFLAGS_BY_NAME: dict[str, int]
 
@@ -134,6 +148,8 @@ class DocTestRunner:
     original_optionflags: int
     tries: int
     failures: int
+    if sys.version_info >= (3, 13):
+        skips: int
     test: DocTest
     def __init__(self, checker: OutputChecker | None = None, verbose: bool | None = None, optionflags: int = 0) -> None: ...
     def report_start(self, out: _Out, test: DocTest, example: Example) -> None: ...
diff --git a/mypy/typeshed/stdlib/email/_header_value_parser.pyi b/mypy/typeshed/stdlib/email/_header_value_parser.pyi
index 806fc84cf784..ff405a8b61d2 100644
--- a/mypy/typeshed/stdlib/email/_header_value_parser.pyi
+++ b/mypy/typeshed/stdlib/email/_header_value_parser.pyi
@@ -16,6 +16,10 @@ TOKEN_ENDS: Final[set[str]]
 ASPECIALS: Final[set[str]]
 ATTRIBUTE_ENDS: Final[set[str]]
 EXTENDED_ATTRIBUTE_ENDS: Final[set[str]]
+# Added in Python 3.8.20, 3.9.20, 3.10.15, 3.11.10, 3.12.5
+NLSET: Final[set[str]]
+# Added in Python 3.8.20, 3.9.20, 3.10.15, 3.11.10, 3.12.5
+SPECIALSNL: Final[set[str]]
 
 def quote_string(value: Any) -> str: ...
 
diff --git a/mypy/typeshed/stdlib/email/_policybase.pyi b/mypy/typeshed/stdlib/email/_policybase.pyi
index a3dd61a282ce..9e1f653c9d78 100644
--- a/mypy/typeshed/stdlib/email/_policybase.pyi
+++ b/mypy/typeshed/stdlib/email/_policybase.pyi
@@ -3,20 +3,9 @@ from collections.abc import Callable
 from email.errors import MessageDefect
 from email.header import Header
 from email.message import Message
-from typing import Any
 from typing_extensions import Self
 
 class _PolicyBase:
-    def __add__(self, other: Any) -> Self: ...
-    def clone(self, **kw: Any) -> Self: ...
-
-class Policy(_PolicyBase, metaclass=ABCMeta):
-    max_line_length: int | None
-    linesep: str
-    cte_type: str
-    raise_on_defect: bool
-    mangle_from_: bool
-    message_factory: Callable[[Policy], Message] | None
     def __init__(
         self,
         *,
@@ -24,9 +13,35 @@ class Policy(_PolicyBase, metaclass=ABCMeta):
         linesep: str = "\n",
         cte_type: str = "8bit",
         raise_on_defect: bool = False,
-        mangle_from_: bool = False,
+        mangle_from_: bool = ...,  # default depends on sub-class
         message_factory: Callable[[Policy], Message] | None = None,
+        # Added in Python 3.8.20, 3.9.20, 3.10.15, 3.11.10, 3.12.5
+        verify_generated_headers: bool = True,
     ) -> None: ...
+    def clone(
+        self,
+        *,
+        max_line_length: int | None = ...,
+        linesep: str = ...,
+        cte_type: str = ...,
+        raise_on_defect: bool = ...,
+        mangle_from_: bool = ...,
+        message_factory: Callable[[Policy], Message] | None = ...,
+        # Added in Python 3.8.20, 3.9.20, 3.10.15, 3.11.10, 3.12.5
+        verify_generated_headers: bool = ...,
+    ) -> Self: ...
+    def __add__(self, other: Policy) -> Self: ...
+
+class Policy(_PolicyBase, metaclass=ABCMeta):
+    max_line_length: int | None
+    linesep: str
+    cte_type: str
+    raise_on_defect: bool
+    mangle_from_: bool
+    message_factory: Callable[[Policy], Message] | None
+    # Added in Python 3.8.20, 3.9.20, 3.10.15, 3.11.10, 3.12.5
+    verify_generated_headers: bool
+
     def handle_defect(self, obj: Message, defect: MessageDefect) -> None: ...
     def register_defect(self, obj: Message, defect: MessageDefect) -> None: ...
     def header_max_count(self, name: str) -> int | None: ...
diff --git a/mypy/typeshed/stdlib/email/errors.pyi b/mypy/typeshed/stdlib/email/errors.pyi
index c54f1560c9ae..f105576c5ee4 100644
--- a/mypy/typeshed/stdlib/email/errors.pyi
+++ b/mypy/typeshed/stdlib/email/errors.pyi
@@ -7,6 +7,9 @@ class BoundaryError(MessageParseError): ...
 class MultipartConversionError(MessageError, TypeError): ...
 class CharsetError(MessageError): ...
 
+# Added in Python 3.8.20, 3.9.20, 3.10.15, 3.11.10, 3.12.5
+class HeaderWriteError(MessageError): ...
+
 class MessageDefect(ValueError):
     def __init__(self, line: str | None = None) -> None: ...
 
diff --git a/mypy/typeshed/stdlib/email/utils.pyi b/mypy/typeshed/stdlib/email/utils.pyi
index 9dab22c18f6c..dc3eecb5ef7f 100644
--- a/mypy/typeshed/stdlib/email/utils.pyi
+++ b/mypy/typeshed/stdlib/email/utils.pyi
@@ -30,20 +30,12 @@ _PDTZ: TypeAlias = tuple[int, int, int, int, int, int, int, int, int, int | None
 def quote(str: str) -> str: ...
 def unquote(str: str) -> str: ...
 
-if sys.version_info >= (3, 13):
-    def parseaddr(addr: str | list[str], *, strict: bool = True) -> tuple[str, str]: ...
-
-else:
-    def parseaddr(addr: str) -> tuple[str, str]: ...
-
+# `strict` parameter added in Python 3.8.20, 3.9.20, 3.10.15, 3.11.10, 3.12.5
+def parseaddr(addr: str | list[str], *, strict: bool = True) -> tuple[str, str]: ...
 def formataddr(pair: tuple[str | None, str], charset: str | Charset = "utf-8") -> str: ...
 
-if sys.version_info >= (3, 13):
-    def getaddresses(fieldvalues: Iterable[str], *, strict: bool = True) -> list[tuple[str, str]]: ...
-
-else:
-    def getaddresses(fieldvalues: Iterable[str]) -> list[tuple[str, str]]: ...
-
+# `strict` parameter added in Python 3.8.20, 3.9.20, 3.10.15, 3.11.10, 3.12.5
+def getaddresses(fieldvalues: Iterable[str], *, strict: bool = True) -> list[tuple[str, str]]: ...
 @overload
 def parsedate(data: None) -> None: ...
 @overload
diff --git a/mypy/typeshed/stdlib/importlib/abc.pyi b/mypy/typeshed/stdlib/importlib/abc.pyi
index 3937481159dc..4a0a70d0930d 100644
--- a/mypy/typeshed/stdlib/importlib/abc.pyi
+++ b/mypy/typeshed/stdlib/importlib/abc.pyi
@@ -145,10 +145,10 @@ if sys.version_info >= (3, 9):
         # which is not the case.
         @overload
         @abstractmethod
-        def open(self, mode: Literal["r"] = "r", /, *, encoding: str | None = None, errors: str | None = None) -> IO[str]: ...
+        def open(self, mode: Literal["r"] = "r", *, encoding: str | None = None, errors: str | None = None) -> IO[str]: ...
         @overload
         @abstractmethod
-        def open(self, mode: Literal["rb"], /) -> IO[bytes]: ...
+        def open(self, mode: Literal["rb"]) -> IO[bytes]: ...
         @property
         @abstractmethod
         def name(self) -> str: ...
diff --git a/mypy/typeshed/stdlib/importlib/resources/__init__.pyi b/mypy/typeshed/stdlib/importlib/resources/__init__.pyi
index 8d656563772c..f82df8c591fa 100644
--- a/mypy/typeshed/stdlib/importlib/resources/__init__.pyi
+++ b/mypy/typeshed/stdlib/importlib/resources/__init__.pyi
@@ -7,10 +7,15 @@ from types import ModuleType
 from typing import Any, BinaryIO, TextIO
 from typing_extensions import TypeAlias
 
+if sys.version_info >= (3, 11):
+    from importlib.resources._common import Package as Package
+else:
+    Package: TypeAlias = str | ModuleType
+
 if sys.version_info >= (3, 9):
     from importlib.abc import Traversable
 
-__all__ = ["Package", "Resource", "contents", "is_resource", "open_binary", "open_text", "path", "read_binary", "read_text"]
+__all__ = ["Package", "contents", "is_resource", "open_binary", "open_text", "path", "read_binary", "read_text"]
 
 if sys.version_info >= (3, 9):
     __all__ += ["as_file", "files"]
@@ -18,26 +23,45 @@ if sys.version_info >= (3, 9):
 if sys.version_info >= (3, 10):
     __all__ += ["ResourceReader"]
 
-Package: TypeAlias = str | ModuleType
+if sys.version_info < (3, 13):
+    __all__ += ["Resource"]
 
-if sys.version_info >= (3, 11):
-    Resource: TypeAlias = str
-else:
+if sys.version_info < (3, 11):
     Resource: TypeAlias = str | os.PathLike[Any]
+elif sys.version_info < (3, 13):
+    Resource: TypeAlias = str
 
-def open_binary(package: Package, resource: Resource) -> BinaryIO: ...
-def open_text(package: Package, resource: Resource, encoding: str = "utf-8", errors: str = "strict") -> TextIO: ...
-def read_binary(package: Package, resource: Resource) -> bytes: ...
-def read_text(package: Package, resource: Resource, encoding: str = "utf-8", errors: str = "strict") -> str: ...
-def path(package: Package, resource: Resource) -> AbstractContextManager[Path]: ...
-def is_resource(package: Package, name: str) -> bool: ...
-def contents(package: Package) -> Iterator[str]: ...
+if sys.version_info >= (3, 13):
+    from importlib.resources._common import Anchor as Anchor
 
-if sys.version_info >= (3, 9):
+    __all__ += ["Anchor"]
+
+    from importlib.resources._functional import (
+        contents as contents,
+        is_resource as is_resource,
+        open_binary as open_binary,
+        open_text as open_text,
+        path as path,
+        read_binary as read_binary,
+        read_text as read_text,
+    )
+
+else:
+    def open_binary(package: Package, resource: Resource) -> BinaryIO: ...
+    def open_text(package: Package, resource: Resource, encoding: str = "utf-8", errors: str = "strict") -> TextIO: ...
+    def read_binary(package: Package, resource: Resource) -> bytes: ...
+    def read_text(package: Package, resource: Resource, encoding: str = "utf-8", errors: str = "strict") -> str: ...
+    def path(package: Package, resource: Resource) -> AbstractContextManager[Path]: ...
+    def is_resource(package: Package, name: str) -> bool: ...
+    def contents(package: Package) -> Iterator[str]: ...
+
+if sys.version_info >= (3, 11):
+    from importlib.resources._common import as_file as as_file
+elif sys.version_info >= (3, 9):
     def as_file(path: Traversable) -> AbstractContextManager[Path]: ...
 
-if sys.version_info >= (3, 12):
-    def files(anchor: Package | None = ...) -> Traversable: ...
+if sys.version_info >= (3, 11):
+    from importlib.resources._common import files as files
 
 elif sys.version_info >= (3, 9):
     def files(package: Package) -> Traversable: ...
diff --git a/mypy/typeshed/stdlib/importlib/resources/_common.pyi b/mypy/typeshed/stdlib/importlib/resources/_common.pyi
new file mode 100644
index 000000000000..f04f70f25e23
--- /dev/null
+++ b/mypy/typeshed/stdlib/importlib/resources/_common.pyi
@@ -0,0 +1,42 @@
+import sys
+
+# Even though this file is 3.11+ only, Pyright will complain in stubtest for older versions.
+if sys.version_info >= (3, 11):
+    import types
+    from collections.abc import Callable
+    from contextlib import AbstractContextManager
+    from importlib.abc import ResourceReader, Traversable
+    from pathlib import Path
+    from typing import overload
+    from typing_extensions import TypeAlias, deprecated
+
+    Package: TypeAlias = str | types.ModuleType
+
+    if sys.version_info >= (3, 12):
+        Anchor: TypeAlias = Package
+
+        def package_to_anchor(
+            func: Callable[[Anchor | None], Traversable]
+        ) -> Callable[[Anchor | None, Anchor | None], Traversable]: ...
+        @overload
+        def files(anchor: Anchor | None = None) -> Traversable: ...
+        @overload
+        @deprecated("First parameter to files is renamed to 'anchor'")
+        def files(package: Anchor | None = None) -> Traversable: ...
+
+    else:
+        def files(package: Package) -> Traversable: ...
+
+    def get_resource_reader(package: types.ModuleType) -> ResourceReader | None: ...
+
+    if sys.version_info >= (3, 12):
+        def resolve(cand: Anchor | None) -> types.ModuleType: ...
+
+    else:
+        def resolve(cand: Package) -> types.ModuleType: ...
+
+    if sys.version_info < (3, 12):
+        def get_package(package: Package) -> types.ModuleType: ...
+
+    def from_package(package: types.ModuleType) -> Traversable: ...
+    def as_file(path: Traversable) -> AbstractContextManager[Path]: ...
diff --git a/mypy/typeshed/stdlib/importlib/resources/_functional.pyi b/mypy/typeshed/stdlib/importlib/resources/_functional.pyi
new file mode 100644
index 000000000000..97e46bdf0a53
--- /dev/null
+++ b/mypy/typeshed/stdlib/importlib/resources/_functional.pyi
@@ -0,0 +1,30 @@
+import sys
+
+# Even though this file is 3.13+ only, Pyright will complain in stubtest for older versions.
+if sys.version_info >= (3, 13):
+    from _typeshed import StrPath
+    from collections.abc import Iterator
+    from contextlib import AbstractContextManager
+    from importlib.resources._common import Anchor
+    from io import TextIOWrapper
+    from pathlib import Path
+    from typing import BinaryIO, overload
+    from typing_extensions import Unpack
+
+    def open_binary(anchor: Anchor, *path_names: StrPath) -> BinaryIO: ...
+    @overload
+    def open_text(
+        anchor: Anchor, *path_names: Unpack[tuple[StrPath]], encoding: str | None = "utf-8", errors: str | None = "strict"
+    ) -> TextIOWrapper: ...
+    @overload
+    def open_text(anchor: Anchor, *path_names: StrPath, encoding: str | None, errors: str | None = "strict") -> TextIOWrapper: ...
+    def read_binary(anchor: Anchor, *path_names: StrPath) -> bytes: ...
+    @overload
+    def read_text(
+        anchor: Anchor, *path_names: Unpack[tuple[StrPath]], encoding: str | None = "utf-8", errors: str | None = "strict"
+    ) -> str: ...
+    @overload
+    def read_text(anchor: Anchor, *path_names: StrPath, encoding: str | None, errors: str | None = "strict") -> str: ...
+    def path(anchor: Anchor, *path_names: StrPath) -> AbstractContextManager[Path]: ...
+    def is_resource(anchor: Anchor, *path_names: StrPath) -> bool: ...
+    def contents(anchor: Anchor, *path_names: StrPath) -> Iterator[str]: ...
diff --git a/mypy/typeshed/stdlib/io.pyi b/mypy/typeshed/stdlib/io.pyi
index 2d64d261951d..7607608696dd 100644
--- a/mypy/typeshed/stdlib/io.pyi
+++ b/mypy/typeshed/stdlib/io.pyi
@@ -84,7 +84,6 @@ class RawIOBase(IOBase):
     def read(self, size: int = -1, /) -> bytes | None: ...
 
 class BufferedIOBase(IOBase):
-    raw: RawIOBase  # This is not part of the BufferedIOBase API and may not exist on some implementations.
     def detach(self) -> RawIOBase: ...
     def readinto(self, buffer: WriteableBuffer, /) -> int: ...
     def write(self, buffer: ReadableBuffer, /) -> int: ...
@@ -119,11 +118,13 @@ class BytesIO(BufferedIOBase, BinaryIO):  # type: ignore[misc]  # incompatible d
     def read1(self, size: int | None = -1, /) -> bytes: ...
 
 class BufferedReader(BufferedIOBase, BinaryIO):  # type: ignore[misc]  # incompatible definitions of methods in the base classes
+    raw: RawIOBase
     def __enter__(self) -> Self: ...
     def __init__(self, raw: RawIOBase, buffer_size: int = ...) -> None: ...
     def peek(self, size: int = 0, /) -> bytes: ...
 
 class BufferedWriter(BufferedIOBase, BinaryIO):  # type: ignore[misc]  # incompatible definitions of writelines in the base classes
+    raw: RawIOBase
     def __enter__(self) -> Self: ...
     def __init__(self, raw: RawIOBase, buffer_size: int = ...) -> None: ...
     def write(self, buffer: ReadableBuffer, /) -> int: ...
diff --git a/mypy/typeshed/stdlib/nt.pyi b/mypy/typeshed/stdlib/nt.pyi
index 4066096f4c71..e1d57d09a9bd 100644
--- a/mypy/typeshed/stdlib/nt.pyi
+++ b/mypy/typeshed/stdlib/nt.pyi
@@ -107,5 +107,7 @@ if sys.platform == "win32":
             listvolumes as listvolumes,
             set_blocking as set_blocking,
         )
+    if sys.version_info >= (3, 13):
+        from os import fchmod as fchmod, lchmod as lchmod
 
     environ: dict[str, str]
diff --git a/mypy/typeshed/stdlib/os/__init__.pyi b/mypy/typeshed/stdlib/os/__init__.pyi
index 700e0e9df310..d7bb4883a0f2 100644
--- a/mypy/typeshed/stdlib/os/__init__.pyi
+++ b/mypy/typeshed/stdlib/os/__init__.pyi
@@ -673,7 +673,6 @@ if sys.version_info >= (3, 12) or sys.platform != "win32":
     def set_blocking(fd: int, blocking: bool, /) -> None: ...
 
 if sys.platform != "win32":
-    def fchmod(fd: int, mode: int) -> None: ...
     def fchown(fd: int, uid: int, gid: int) -> None: ...
     def fpathconf(fd: int, name: str | int, /) -> int: ...
     def fstatvfs(fd: int, /) -> statvfs_result: ...
@@ -754,7 +753,6 @@ def chmod(path: FileDescriptorOrPath, mode: int, *, dir_fd: int | None = None, f
 if sys.platform != "win32" and sys.platform != "linux":
     def chflags(path: StrOrBytesPath, flags: int, follow_symlinks: bool = True) -> None: ...  # some flavors of Unix
     def lchflags(path: StrOrBytesPath, flags: int) -> None: ...
-    def lchmod(path: StrOrBytesPath, mode: int) -> None: ...
 
 if sys.platform != "win32":
     def chroot(path: StrOrBytesPath) -> None: ...
@@ -1179,3 +1177,12 @@ if sys.version_info >= (3, 13) and sys.platform == "linux":
     def timerfd_settime_ns(fd: FileDescriptor, /, *, flags: int = 0, initial: int = 0, interval: int = 0) -> tuple[int, int]: ...
     def timerfd_gettime(fd: FileDescriptor, /) -> tuple[float, float]: ...
     def timerfd_gettime_ns(fd: FileDescriptor, /) -> tuple[int, int]: ...
+
+if sys.version_info >= (3, 13) or sys.platform != "win32":
+    # Added to Windows in 3.13.
+    def fchmod(fd: int, mode: int) -> None: ...
+
+if sys.platform != "linux":
+    if sys.version_info >= (3, 13) or sys.platform != "win32":
+        # Added to Windows in 3.13.
+        def lchmod(path: StrOrBytesPath, mode: int) -> None: ...
diff --git a/mypy/typeshed/stdlib/subprocess.pyi b/mypy/typeshed/stdlib/subprocess.pyi
index 2a5859807b51..703a5012012c 100644
--- a/mypy/typeshed/stdlib/subprocess.pyi
+++ b/mypy/typeshed/stdlib/subprocess.pyi
@@ -2582,6 +2582,11 @@ else:
 def list2cmdline(seq: Iterable[StrOrBytesPath]) -> str: ...  # undocumented
 
 if sys.platform == "win32":
+    if sys.version_info >= (3, 13):
+        from _winapi import STARTF_FORCEOFFFEEDBACK, STARTF_FORCEONFEEDBACK
+
+        __all__ += ["STARTF_FORCEOFFFEEDBACK", "STARTF_FORCEONFEEDBACK"]
+
     class STARTUPINFO:
         def __init__(
             self,
diff --git a/mypy/typeshed/stdlib/tempfile.pyi b/mypy/typeshed/stdlib/tempfile.pyi
index 62422b84eb37..0c19d56fc7a6 100644
--- a/mypy/typeshed/stdlib/tempfile.pyi
+++ b/mypy/typeshed/stdlib/tempfile.pyi
@@ -253,11 +253,11 @@ class _TemporaryFileWrapper(IO[AnyStr]):
     def truncate(self, size: int | None = ...) -> int: ...
     def writable(self) -> bool: ...
     @overload
-    def write(self: _TemporaryFileWrapper[str], s: str) -> int: ...
+    def write(self: _TemporaryFileWrapper[str], s: str, /) -> int: ...
     @overload
-    def write(self: _TemporaryFileWrapper[bytes], s: ReadableBuffer) -> int: ...
+    def write(self: _TemporaryFileWrapper[bytes], s: ReadableBuffer, /) -> int: ...
     @overload
-    def write(self, s: AnyStr) -> int: ...
+    def write(self, s: AnyStr, /) -> int: ...
     @overload
     def writelines(self: _TemporaryFileWrapper[str], lines: Iterable[str]) -> None: ...
     @overload
diff --git a/mypy/typeshed/stdlib/tkinter/__init__.pyi b/mypy/typeshed/stdlib/tkinter/__init__.pyi
index 2a42eb789731..4d25a04f8eb7 100644
--- a/mypy/typeshed/stdlib/tkinter/__init__.pyi
+++ b/mypy/typeshed/stdlib/tkinter/__init__.pyi
@@ -3025,27 +3025,133 @@ class Text(Widget, XView, YView):
     config = configure
     def bbox(self, index: _TextIndex) -> tuple[int, int, int, int] | None: ...  # type: ignore[override]
     def compare(self, index1: _TextIndex, op: Literal["<", "<=", "==", ">=", ">", "!="], index2: _TextIndex) -> bool: ...
-    @overload
-    def count(self, index1: _TextIndex, index2: _TextIndex) -> tuple[int] | None: ...
-    @overload
-    def count(self, index1: _TextIndex, index2: _TextIndex, arg: _WhatToCount | Literal["update"], /) -> tuple[int] | None: ...
-    @overload
-    def count(self, index1: _TextIndex, index2: _TextIndex, arg1: Literal["update"], arg2: _WhatToCount, /) -> int | None: ...
-    @overload
-    def count(self, index1: _TextIndex, index2: _TextIndex, arg1: _WhatToCount, arg2: Literal["update"], /) -> int | None: ...
-    @overload
-    def count(self, index1: _TextIndex, index2: _TextIndex, arg1: _WhatToCount, arg2: _WhatToCount, /) -> tuple[int, int]: ...
-    @overload
-    def count(
-        self,
-        index1: _TextIndex,
-        index2: _TextIndex,
-        arg1: _WhatToCount | Literal["update"],
-        arg2: _WhatToCount | Literal["update"],
-        arg3: _WhatToCount | Literal["update"],
-        /,
-        *args: _WhatToCount | Literal["update"],
-    ) -> tuple[int, ...]: ...
+    if sys.version_info >= (3, 13):
+        @overload
+        def count(self, index1: _TextIndex, index2: _TextIndex, *, return_ints: Literal[True]) -> int: ...
+        @overload
+        def count(
+            self, index1: _TextIndex, index2: _TextIndex, arg: _WhatToCount | Literal["update"], /, *, return_ints: Literal[True]
+        ) -> int: ...
+        @overload
+        def count(
+            self,
+            index1: _TextIndex,
+            index2: _TextIndex,
+            arg1: Literal["update"],
+            arg2: _WhatToCount,
+            /,
+            *,
+            return_ints: Literal[True],
+        ) -> int: ...
+        @overload
+        def count(
+            self,
+            index1: _TextIndex,
+            index2: _TextIndex,
+            arg1: _WhatToCount,
+            arg2: Literal["update"],
+            /,
+            *,
+            return_ints: Literal[True],
+        ) -> int: ...
+        @overload
+        def count(
+            self, index1: _TextIndex, index2: _TextIndex, arg1: _WhatToCount, arg2: _WhatToCount, /, *, return_ints: Literal[True]
+        ) -> tuple[int, int]: ...
+        @overload
+        def count(
+            self,
+            index1: _TextIndex,
+            index2: _TextIndex,
+            arg1: _WhatToCount | Literal["update"],
+            arg2: _WhatToCount | Literal["update"],
+            arg3: _WhatToCount | Literal["update"],
+            /,
+            *args: _WhatToCount | Literal["update"],
+            return_ints: Literal[True],
+        ) -> tuple[int, ...]: ...
+        @overload
+        def count(self, index1: _TextIndex, index2: _TextIndex, *, return_ints: Literal[False] = False) -> tuple[int] | None: ...
+        @overload
+        def count(
+            self,
+            index1: _TextIndex,
+            index2: _TextIndex,
+            arg: _WhatToCount | Literal["update"],
+            /,
+            *,
+            return_ints: Literal[False] = False,
+        ) -> tuple[int] | None: ...
+        @overload
+        def count(
+            self,
+            index1: _TextIndex,
+            index2: _TextIndex,
+            arg1: Literal["update"],
+            arg2: _WhatToCount,
+            /,
+            *,
+            return_ints: Literal[False] = False,
+        ) -> int | None: ...
+        @overload
+        def count(
+            self,
+            index1: _TextIndex,
+            index2: _TextIndex,
+            arg1: _WhatToCount,
+            arg2: Literal["update"],
+            /,
+            *,
+            return_ints: Literal[False] = False,
+        ) -> int | None: ...
+        @overload
+        def count(
+            self,
+            index1: _TextIndex,
+            index2: _TextIndex,
+            arg1: _WhatToCount,
+            arg2: _WhatToCount,
+            /,
+            *,
+            return_ints: Literal[False] = False,
+        ) -> tuple[int, int]: ...
+        @overload
+        def count(
+            self,
+            index1: _TextIndex,
+            index2: _TextIndex,
+            arg1: _WhatToCount | Literal["update"],
+            arg2: _WhatToCount | Literal["update"],
+            arg3: _WhatToCount | Literal["update"],
+            /,
+            *args: _WhatToCount | Literal["update"],
+            return_ints: Literal[False] = False,
+        ) -> tuple[int, ...]: ...
+    else:
+        @overload
+        def count(self, index1: _TextIndex, index2: _TextIndex) -> tuple[int] | None: ...
+        @overload
+        def count(
+            self, index1: _TextIndex, index2: _TextIndex, arg: _WhatToCount | Literal["update"], /
+        ) -> tuple[int] | None: ...
+        @overload
+        def count(self, index1: _TextIndex, index2: _TextIndex, arg1: Literal["update"], arg2: _WhatToCount, /) -> int | None: ...
+        @overload
+        def count(self, index1: _TextIndex, index2: _TextIndex, arg1: _WhatToCount, arg2: Literal["update"], /) -> int | None: ...
+        @overload
+        def count(self, index1: _TextIndex, index2: _TextIndex, arg1: _WhatToCount, arg2: _WhatToCount, /) -> tuple[int, int]: ...
+        @overload
+        def count(
+            self,
+            index1: _TextIndex,
+            index2: _TextIndex,
+            arg1: _WhatToCount | Literal["update"],
+            arg2: _WhatToCount | Literal["update"],
+            arg3: _WhatToCount | Literal["update"],
+            /,
+            *args: _WhatToCount | Literal["update"],
+        ) -> tuple[int, ...]: ...
+
     @overload
     def debug(self, boolean: None = None) -> bool: ...
     @overload
diff --git a/mypy/typeshed/stdlib/typing.pyi b/mypy/typeshed/stdlib/typing.pyi
index cadd06358d4a..784f30ad7397 100644
--- a/mypy/typeshed/stdlib/typing.pyi
+++ b/mypy/typeshed/stdlib/typing.pyi
@@ -540,7 +540,7 @@ class AsyncIterator(AsyncIterable[_T_co], Protocol[_T_co]):
     def __aiter__(self) -> AsyncIterator[_T_co]: ...
 
 class AsyncGenerator(AsyncIterator[_YieldT_co], Generic[_YieldT_co, _SendT_contra]):
-    def __anext__(self) -> Awaitable[_YieldT_co]: ...
+    def __anext__(self) -> Coroutine[Any, Any, _YieldT_co]: ...
     @abstractmethod
     def asend(self, value: _SendT_contra, /) -> Coroutine[Any, Any, _YieldT_co]: ...
     @overload
diff --git a/mypyc/test-data/run-python312.test b/mypyc/test-data/run-python312.test
index 5e8a388fd8d3..a5a3f058d1e2 100644
--- a/mypyc/test-data/run-python312.test
+++ b/mypyc/test-data/run-python312.test
@@ -1,5 +1,4 @@
 [case testPEP695Basics]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from typing import Any, TypeAliasType, cast
 
 from testutil import assertRaises
@@ -192,7 +191,6 @@ def test_recursive_type_alias() -> None:
 [typing fixtures/typing-full.pyi]
 
 [case testPEP695GenericTypeAlias]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from typing import Callable
 from types import GenericAlias
 
diff --git a/mypyc/test/test_run.py b/mypyc/test/test_run.py
index 37de192a9291..668e5b124841 100644
--- a/mypyc/test/test_run.py
+++ b/mypyc/test/test_run.py
@@ -196,7 +196,6 @@ def run_case_step(self, testcase: DataDrivenTestCase, incremental_step: int) ->
         options.preserve_asts = True
         options.allow_empty_bodies = True
         options.incremental = self.separate
-        options.enable_incomplete_feature.append("NewGenericSyntax")
 
         # Avoid checking modules/packages named 'unchecked', to provide a way
         # to test interacting with code we don't have types for.
diff --git a/test-data/unit/check-errorcodes.test b/test-data/unit/check-errorcodes.test
index c4d72388fba9..10cc145d0c70 100644
--- a/test-data/unit/check-errorcodes.test
+++ b/test-data/unit/check-errorcodes.test
@@ -846,34 +846,48 @@ foo = Foo()
 if foo:  # E: "__main__.foo" has type "Foo" which does not implement __bool__ or __len__ so it could always be true in boolean context  [truthy-bool]
     pass
 
+not foo  # E: "__main__.foo" has type "Foo" which does not implement __bool__ or __len__ so it could always be true in boolean context  [truthy-bool]
+
 zero = 0
 if zero:
     pass
 
+not zero
+
 false = False
 if false:
     pass
 
+not false
+
 null = None
 if null:
     pass
 
+not null
+
 s = ''
 if s:
     pass
 
+not s
+
 good_union: Union[str, int] = 5
 if good_union:
     pass
 if not good_union:
     pass
 
+not good_union
+
 bad_union: Union[Foo, Bar] = Foo()
 if bad_union:  # E: "__main__.bad_union" has type "Union[Foo, Bar]" of which no members implement __bool__ or __len__ so it could always be true in boolean context  [truthy-bool]
     pass
 if not bad_union:  # E: "__main__.bad_union" has type "Union[Foo, Bar]" of which no members implement __bool__ or __len__ so it could always be true in boolean context  [truthy-bool]
     pass
 
+not bad_union  # E: "__main__.bad_union" has type "Union[Foo, Bar]" of which no members implement __bool__ or __len__ so it could always be true in boolean context  [truthy-bool]
+
 # 'object' is special and is treated as potentially falsy
 obj: object = Foo()
 if obj:
@@ -881,18 +895,26 @@ if obj:
 if not obj:
     pass
 
+not obj
+
 lst: List[int] = []
 if lst:
     pass
 
+not lst
+
 a: Any
 if a:
     pass
 
+not a
+
 any_or_object: Union[object, Any]
 if any_or_object:
     pass
 
+not any_or_object
+
 if (my_foo := Foo()):  # E: "__main__.my_foo" has type "Foo" which does not implement __bool__ or __len__ so it could always be true in boolean context  [truthy-bool]
     pass
 
@@ -909,6 +931,8 @@ if not f:  # E: Function "f" could always be true in boolean context  [truthy-fu
     pass
 conditional_result = 'foo' if f else 'bar'  # E: Function "f" could always be true in boolean context  [truthy-function]
 
+not f  # E: Function "f" could always be true in boolean context  [truthy-function]
+
 [case testTruthyIterable]
 # flags: --enable-error-code truthy-iterable
 from typing import Iterable
@@ -916,6 +940,8 @@ def func(var: Iterable[str]) -> None:
     if var:  # E: "var" has type "Iterable[str]" which can always be true in boolean context. Consider using "Collection[str]" instead.  [truthy-iterable]
         ...
 
+    not var  # E: "var" has type "Iterable[str]" which can always be true in boolean context. Consider using "Collection[str]" instead.  [truthy-iterable]
+
 [case testNoOverloadImplementation]
 from typing import overload
 
@@ -1196,3 +1222,17 @@ def f(x: str) -> TypeIs[int]:  # E: Narrowed type "int" is not a subtype of inpu
     pass
 
 [builtins fixtures/tuple.pyi]
+
+
+[case testOverloadedFunctionSignature]
+from typing import overload, Union
+
+@overload
+def process(response1: float,response2: float) -> float:
+    ...
+@overload
+def process(response1: int,response2: int) -> int: # E: Overloaded function signature 2 will never be matched: signature 1's parameter type(s) are the same or broader  [overload-cannot-match]
+    ...
+
+def process(response1,response2)-> Union[float,int]:
+   return response1 + response2
diff --git a/test-data/unit/check-expressions.test b/test-data/unit/check-expressions.test
index 61cee1d00c58..d5ddc910bcd6 100644
--- a/test-data/unit/check-expressions.test
+++ b/test-data/unit/check-expressions.test
@@ -342,7 +342,7 @@ b: bool
 i: str
 j = b or i
 if not j:
-    reveal_type(j) # N: Revealed type is "builtins.str"
+    reveal_type(j) # N: Revealed type is "Literal['']"
 [builtins fixtures/bool.pyi]
 
 [case testAndOr]
diff --git a/test-data/unit/check-functions.test b/test-data/unit/check-functions.test
index b681c544a6bd..96f9815019e6 100644
--- a/test-data/unit/check-functions.test
+++ b/test-data/unit/check-functions.test
@@ -1428,6 +1428,20 @@ else:
                                     # N: Redefinition: \
                                     # N:     def f(x: int = ...) -> None
 
+[case testIncompatibleConditionalFunctionDefinition4]
+from typing import Any, Union, TypeVar
+T1 = TypeVar('T1')
+T2 = TypeVar('T2', bound=Union[int, str])
+x = None # type: Any
+if x:
+    def f(x: T1) -> T1: pass
+else:
+    def f(x: T2) -> T2: pass # E: All conditional function variants must have identical signatures \
+                             # N: Original: \
+                             # N:     def [T1] f(x: T1) -> T1 \
+                             # N: Redefinition: \
+                             # N:     def [T2: Union[int, str]] f(x: T2) -> T2
+
 [case testConditionalFunctionDefinitionUsingDecorator1]
 from typing import Callable
 
diff --git a/test-data/unit/check-narrowing.test b/test-data/unit/check-narrowing.test
index e142fdd5d060..0cb4bf8e4a19 100644
--- a/test-data/unit/check-narrowing.test
+++ b/test-data/unit/check-narrowing.test
@@ -1007,7 +1007,7 @@ str_or_false: Union[Literal[False], str]
 if str_or_false:
     reveal_type(str_or_false)   # N: Revealed type is "builtins.str"
 else:
-    reveal_type(str_or_false)   # N: Revealed type is "Union[Literal[False], builtins.str]"
+    reveal_type(str_or_false)   # N: Revealed type is "Union[Literal[False], Literal['']]"
 
 true_or_false: Literal[True, False]
 
@@ -1017,6 +1017,22 @@ else:
     reveal_type(true_or_false)  # N: Revealed type is "Literal[False]"
 [builtins fixtures/primitives.pyi]
 
+[case testNarrowingFalseyToLiteral]
+from typing import Union
+
+a: str
+b: bytes
+c: int
+d: Union[str, bytes, int]
+
+if not a:
+    reveal_type(a)  # N: Revealed type is "Literal['']"
+if not b:
+    reveal_type(b)  # N: Revealed type is "Literal[b'']"
+if not c:
+    reveal_type(c)  # N: Revealed type is "Literal[0]"
+if not d:
+    reveal_type(d)  # N: Revealed type is "Union[Literal[''], Literal[b''], Literal[0]]"
 
 [case testNarrowingIsInstanceFinalSubclass]
 # flags: --warn-unreachable
diff --git a/test-data/unit/check-optional.test b/test-data/unit/check-optional.test
index f80aa5115bc3..683ce0446915 100644
--- a/test-data/unit/check-optional.test
+++ b/test-data/unit/check-optional.test
@@ -53,14 +53,14 @@ x = None  # type:  Optional[int]
 if x:
   reveal_type(x)  # N: Revealed type is "builtins.int"
 else:
-  reveal_type(x)  # N: Revealed type is "Union[builtins.int, None]"
+  reveal_type(x)  # N: Revealed type is "Union[Literal[0], None]"
 [builtins fixtures/bool.pyi]
 
 [case testIfNotCases]
 from typing import Optional
 x = None  # type:  Optional[int]
 if not x:
-  reveal_type(x)  # N: Revealed type is "Union[builtins.int, None]"
+  reveal_type(x)  # N: Revealed type is "Union[Literal[0], None]"
 else:
   reveal_type(x)  # N: Revealed type is "builtins.int"
 [builtins fixtures/bool.pyi]
@@ -109,13 +109,13 @@ reveal_type(z2)  # N: Revealed type is "Union[builtins.int, builtins.str, None]"
 from typing import Optional
 x = None  # type: Optional[str]
 y1 = x and 'b'
-reveal_type(y1)  # N: Revealed type is "Union[builtins.str, None]"
+reveal_type(y1)  # N: Revealed type is "Union[Literal[''], None, builtins.str]"
 y2 = x and 1  # x could be '', so...
-reveal_type(y2)  # N: Revealed type is "Union[builtins.str, None, builtins.int]"
+reveal_type(y2)  # N: Revealed type is "Union[Literal[''], None, builtins.int]"
 z1 = 'b' and x
 reveal_type(z1)  # N: Revealed type is "Union[builtins.str, None]"
 z2 = int() and x
-reveal_type(z2)  # N: Revealed type is "Union[builtins.int, builtins.str, None]"
+reveal_type(z2)  # N: Revealed type is "Union[Literal[0], builtins.str, None]"
 
 [case testLambdaReturningNone]
 f = lambda: None
diff --git a/test-data/unit/check-parameter-specification.test b/test-data/unit/check-parameter-specification.test
index c2afb61586a8..38fb62fe78e0 100644
--- a/test-data/unit/check-parameter-specification.test
+++ b/test-data/unit/check-parameter-specification.test
@@ -1836,6 +1836,15 @@ c: C[int, [int, str], str]  # E: Nested parameter specifications are not allowed
 reveal_type(c)  # N: Revealed type is "__main__.C[Any]"
 [builtins fixtures/paramspec.pyi]
 
+[case testParamSpecInheritNoCrashOnNested]
+from typing import Generic
+from typing_extensions import ParamSpec
+
+P = ParamSpec("P")
+class C(Generic[P]): ...
+class D(C[int, [int, str], str]): ... # E: Nested parameter specifications are not allowed
+[builtins fixtures/paramspec.pyi]
+
 [case testParamSpecConcatenateSelfType]
 from typing import Callable
 from typing_extensions import ParamSpec, Concatenate
@@ -2183,3 +2192,114 @@ parametrize(_test, Case(1, b=2), Case(3, b=4))
 parametrize(_test, Case(1, 2), Case(3))
 parametrize(_test, Case(1, 2), Case(3, b=4))
 [builtins fixtures/paramspec.pyi]
+
+[case testRunParamSpecInsufficientArgs]
+from typing_extensions import ParamSpec, Concatenate
+from typing import Callable
+
+_P = ParamSpec("_P")
+
+def run(predicate: Callable[_P, None], *args: _P.args, **kwargs: _P.kwargs) -> None:  # N: "run" defined here
+    predicate()  # E: Too few arguments
+    predicate(*args)  # E: Too few arguments
+    predicate(**kwargs)  # E: Too few arguments
+    predicate(*args, **kwargs)
+
+def fn() -> None: ...
+def fn_args(x: int) -> None: ...
+def fn_posonly(x: int, /) -> None: ...
+
+run(fn)
+run(fn_args, 1)
+run(fn_args, x=1)
+run(fn_posonly, 1)
+run(fn_posonly, x=1)  # E: Unexpected keyword argument "x" for "run"
+
+[builtins fixtures/paramspec.pyi]
+
+[case testRunParamSpecConcatenateInsufficientArgs]
+from typing_extensions import ParamSpec, Concatenate
+from typing import Callable
+
+_P = ParamSpec("_P")
+
+def run(predicate: Callable[Concatenate[int, _P], None], *args: _P.args, **kwargs: _P.kwargs) -> None:  # N: "run" defined here
+    predicate()  # E: Too few arguments
+    predicate(1)  # E: Too few arguments
+    predicate(1, *args)  # E: Too few arguments
+    predicate(1, *args)  # E: Too few arguments
+    predicate(1, **kwargs)  # E: Too few arguments
+    predicate(*args, **kwargs)  # E: Argument 1 has incompatible type "*_P.args"; expected "int"
+    predicate(1, *args, **kwargs)
+
+def fn() -> None: ...
+def fn_args(x: int, y: str) -> None: ...
+def fn_posonly(x: int, /) -> None: ...
+def fn_posonly_args(x: int, /, y: str) -> None: ...
+
+run(fn)  # E: Argument 1 to "run" has incompatible type "Callable[[], None]"; expected "Callable[[int], None]"
+run(fn_args, 1, 'a')  # E: Too many arguments for "run" \
+                      # E: Argument 2 to "run" has incompatible type "int"; expected "str"
+run(fn_args, y='a')
+run(fn_args, 'a')
+run(fn_posonly)
+run(fn_posonly, x=1)  # E: Unexpected keyword argument "x" for "run"
+run(fn_posonly_args)  # E: Missing positional argument "y" in call to "run"
+run(fn_posonly_args, 'a')
+run(fn_posonly_args, y='a')
+
+[builtins fixtures/paramspec.pyi]
+
+[case testRunParamSpecConcatenateInsufficientArgsInDecorator]
+from typing_extensions import ParamSpec, Concatenate
+from typing import Callable
+
+P = ParamSpec("P")
+
+def decorator(fn: Callable[Concatenate[str, P], None]) -> Callable[P, None]:
+    def inner(*args: P.args, **kwargs: P.kwargs) -> None:
+        fn("value")  # E: Too few arguments
+        fn("value", *args)  # E: Too few arguments
+        fn("value", **kwargs)  # E: Too few arguments
+        fn(*args, **kwargs)  # E: Argument 1 has incompatible type "*P.args"; expected "str"
+        fn("value", *args, **kwargs)
+    return inner
+
+@decorator
+def foo(s: str, s2: str) -> None: ...
+
+[builtins fixtures/paramspec.pyi]
+
+[case testRunParamSpecOverload]
+from typing_extensions import ParamSpec
+from typing import Callable, NoReturn, TypeVar, Union, overload
+
+P = ParamSpec("P")
+T = TypeVar("T")
+
+@overload
+def capture(
+    sync_fn: Callable[P, NoReturn],
+    *args: P.args,
+    **kwargs: P.kwargs,
+) -> int: ...
+@overload
+def capture(
+    sync_fn: Callable[P, T],
+    *args: P.args,
+    **kwargs: P.kwargs,
+) -> Union[T, int]: ...
+def capture(
+    sync_fn: Callable[P, T],
+    *args: P.args,
+    **kwargs: P.kwargs,
+) -> Union[T, int]:
+    return sync_fn(*args, **kwargs)
+
+def fn() -> str: return ''
+def err() -> NoReturn: ...
+
+reveal_type(capture(fn))  # N: Revealed type is "Union[builtins.str, builtins.int]"
+reveal_type(capture(err))  # N: Revealed type is "builtins.int"
+
+[builtins fixtures/paramspec.pyi]
diff --git a/test-data/unit/check-python312.test b/test-data/unit/check-python312.test
index a3f4c87120cd..085cc052705d 100644
--- a/test-data/unit/check-python312.test
+++ b/test-data/unit/check-python312.test
@@ -1,70 +1,56 @@
-[case test695TypeAlias]
-type MyInt = int  # E: PEP 695 type aliases are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support
+[case testPEP695TypeAliasBasic]
+type MyInt = int
 
 def f(x: MyInt) -> MyInt:
     return reveal_type(x)  # N: Revealed type is "builtins.int"
 
-type MyList[T] = list[T]  # E: PEP 695 type aliases are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support \
-                          # E: Name "T" is not defined
+type MyList[T] = list[T]
 
-def g(x: MyList[int]) -> MyList[int]:  # E: Variable "__main__.MyList" is not valid as a type \
-                                       # N: See https://mypy.readthedocs.io/en/stable/common_issues.html#variables-vs-type-aliases
-    return reveal_type(x)  # N: Revealed type is "MyList?[builtins.int]"
+def g(x: MyList[int]) -> MyList[int]:
+    return reveal_type(x)  # N: Revealed type is "builtins.list[builtins.int]"
 
-type MyInt2 = int  # type: ignore[valid-type]
+type MyInt2 = int
 
 def h(x: MyInt2) -> MyInt2:
     return reveal_type(x)  # N: Revealed type is "builtins.int"
 
-[case test695Class]
-class MyGen[T]:  # E: PEP 695 generics are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support
-    def __init__(self, x: T) -> None:  # E: Name "T" is not defined
+[case testPEP695Class]
+class MyGen[T]:
+    def __init__(self, x: T) -> None:
         self.x = x
 
-def f(x: MyGen[int]):  # E: "MyGen" expects no type arguments, but 1 given
-    reveal_type(x.x)  # N: Revealed type is "Any"
+def f(x: MyGen[int]):
+    reveal_type(x.x)  # N: Revealed type is "builtins.int"
 
-[case test695Function]
-def f[T](x: T) -> T:  # E: PEP 695 generics are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support \
-                      # E: Name "T" is not defined
-    return reveal_type(x)  # N: Revealed type is "Any"
+[case testPEP695Function]
+def f[T](x: T) -> T:
+    return reveal_type(x)  # N: Revealed type is "T`-1"
 
-reveal_type(f(1))  # N: Revealed type is "Any"
+reveal_type(f(1))  # N: Revealed type is "builtins.int"
 
-async def g[T](x: T) -> T:  # E: PEP 695 generics are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support \
-                            # E: Name "T" is not defined
-    return reveal_type(x)  # N: Revealed type is "Any"
+async def g[T](x: T) -> T:
+    return reveal_type(x)  # N: Revealed type is "T`-1"
 
-reveal_type(g(1))  # E: Value of type "Coroutine[Any, Any, Any]" must be used \
+reveal_type(g(1))  # E: Value of type "Coroutine[Any, Any, int]" must be used \
                    # N: Are you missing an await? \
-                   # N: Revealed type is "typing.Coroutine[Any, Any, Any]"
+                   # N: Revealed type is "typing.Coroutine[Any, Any, builtins.int]"
 
-[case test695TypeVar]
+[case testPEP695TypeVarBasic]
 from typing import Callable
-type Alias1[T: int] = list[T]  # E: PEP 695 type aliases are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support \
-                               # E: Name "T" is not defined
-type Alias2[**P] = Callable[P, int]  # E: PEP 695 type aliases are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support \
-                                     # E: Value of type "int" is not indexable \
-                                     # E: Name "P" is not defined
-type Alias3[*Ts] = tuple[*Ts]  # E: PEP 695 type aliases are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support \
-                               # E: Name "Ts" is not defined
-
-class Cls1[T: int]: ...  # E: PEP 695 generics are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support
-class Cls2[**P]: ...  # E: PEP 695 generics are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support
-class Cls3[*Ts]: ...  # E: PEP 695 generics are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support
-
-def func1[T: int](x: T) -> T: ...  # E: PEP 695 generics are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support \
-                                   # E: Name "T" is not defined
-
-def func2[**P](x: Callable[P, int]) -> Callable[P, str]: ...  # E: PEP 695 generics are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support \
-                                                              # E: The first argument to Callable must be a list of types, parameter specification, or "..." \
-                                                              # N: See https://mypy.readthedocs.io/en/stable/kinds_of_types.html#callable-types-and-lambdas \
-                                                              # E: Name "P" is not defined
-def func3[*Ts](x: tuple[*Ts]) -> tuple[int, *Ts]: ...  # E: PEP 695 generics are not yet supported. Use --enable-incomplete-feature=NewGenericSyntax for experimental support \
-                                                       # E: Name "Ts" is not defined
+type Alias1[T: int] = list[T]
+type Alias2[**P] = Callable[P, int]
+type Alias3[*Ts] = tuple[*Ts]
+
+class Cls1[T: int]: ...
+class Cls2[**P]: ...
+class Cls3[*Ts]: ...
+
+def func1[T: int](x: T) -> T: ...
+def func2[**P](x: Callable[P, int]) -> Callable[P, str]: ...
+def func3[*Ts](x: tuple[*Ts]) -> tuple[int, *Ts]: ...
 [builtins fixtures/tuple.pyi]
 
-[case test695TypeAliasType]
+[case testPEP695TypeAliasType]
 from typing import Callable, TypeAliasType, TypeVar, TypeVarTuple
 
 T = TypeVar("T")
@@ -86,9 +72,13 @@ reveal_type(ba2)  # N: Revealed type is "def (*Any) -> builtins.str"
 [builtins fixtures/tuple.pyi]
 [typing fixtures/typing-full.pyi]
 
-[case testPEP695GenericFunctionSyntax]
-# flags: --enable-incomplete-feature=NewGenericSyntax
+[case testPEP695IncompleteFeatureIsAcceptedButHasNoEffect]
+# mypy: enable-incomplete-feature=NewGenericSyntax
+def f[T](x: T) -> T:
+    return x
+reveal_type(f(1))  # N: Revealed type is "builtins.int"
 
+[case testPEP695GenericFunctionSyntax]
 def ident[TV](x: TV) -> TV:
     y: TV = x
     y = 1  # E: Incompatible types in assignment (expression has type "int", variable has type "TV")
@@ -107,8 +97,6 @@ reveal_type(tup(1, 'x'))  # N: Revealed type is "Tuple[builtins.int, builtins.st
 [builtins fixtures/tuple.pyi]
 
 [case testPEP695GenericClassSyntax]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class C[T]:
     x: T
 
@@ -128,8 +116,6 @@ reveal_type(c.x)  # N: Revealed type is "builtins.int"
 reveal_type(c.ident(1))  # N: Revealed type is "builtins.int"
 
 [case testPEP695GenericMethodInGenericClass]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class C[T]:
     def m[S](self, x: S) -> T | S: ...
 
@@ -139,8 +125,6 @@ b: C[object] = C[int]()
 reveal_type(C[str]().m(1))  # N: Revealed type is "Union[builtins.str, builtins.int]"
 
 [case testPEP695InferVarianceSimpleFromMethod]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class Invariant[T]:
     def f(self, x: T) -> None:
         pass
@@ -178,8 +162,6 @@ if int():
     f = e
 
 [case testPEP695InferVarianceSimpleFromAttribute]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class Invariant1[T]:
     def __init__(self, x: T) -> None:
         self.x = x
@@ -214,8 +196,6 @@ if int():
     b3 = a3  # E: Incompatible types in assignment (expression has type "Invariant3[object]", variable has type "Invariant3[int]")
 
 [case testPEP695InferVarianceRecursive]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class Invariant[T]:
     def f(self, x: Invariant[T]) -> Invariant[T]:
         return x
@@ -233,7 +213,7 @@ b: Invariant[int]
 if int():
     a = b  # E: Incompatible types in assignment (expression has type "Invariant[int]", variable has type "Invariant[object]")
 if int():
-    b = a  # E: Incompatible types in assignment (expression has type "Invariant[object]", variable has type "Invariant[int]")
+    b = a
 
 c: Covariant[object]
 d: Covariant[int]
@@ -249,9 +229,25 @@ if int():
 if int():
     f = e
 
-[case testPEP695InferVarianceCalculateOnDemand]
-# flags: --enable-incomplete-feature=NewGenericSyntax
+[case testPEP695InferVarianceInFrozenDataclass]
+from dataclasses import dataclass
+
+@dataclass(frozen=True)
+class Covariant[T]:
+    x: T
+
+cov1: Covariant[float] = Covariant[int](1)
+cov2: Covariant[int] = Covariant[float](1)  # E: Incompatible types in assignment (expression has type "Covariant[float]", variable has type "Covariant[int]")
+
+@dataclass(frozen=True)
+class Invariant[T]:
+    x: list[T]
 
+inv1: Invariant[float] = Invariant[int]([1])  # E: Incompatible types in assignment (expression has type "Invariant[int]", variable has type "Invariant[float]")
+inv2: Invariant[int] = Invariant[float]([1])  # E: Incompatible types in assignment (expression has type "Invariant[float]", variable has type "Invariant[int]")
+[builtins fixtures/tuple.pyi]
+
+[case testPEP695InferVarianceCalculateOnDemand]
 class Covariant[T]:
     def __init__(self) -> None:
         self.x = [1]
@@ -267,8 +263,6 @@ class Covariant[T]:
     def h(self, x: Covariant[int]) -> None: pass
 
 [case testPEP695InferVarianceNotReadyWhenNeeded]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class Covariant[T]:
     def f(self) -> None:
         c = Covariant[int]()
@@ -309,8 +303,6 @@ if int():
     b = a  # E: Incompatible types in assignment (expression has type "Invariant[object]", variable has type "Invariant[int]")
 
 [case testPEP695InferVarianceNotReadyForJoin]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class Invariant[T]:
     def f(self) -> None:
         # Assume covariance if variance us not ready
@@ -323,8 +315,6 @@ class Invariant[T]:
 reveal_type([Invariant(1), Invariant(object())])   # N: Revealed type is "builtins.list[builtins.object]"
 
 [case testPEP695InferVarianceNotReadyForMeet]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 from typing import TypeVar, Callable
 
 S = TypeVar("S")
@@ -342,9 +332,124 @@ class Invariant[T]:
 
 reveal_type(c(a1, a2))  # N: Revealed type is "Never"
 
-[case testPEP695InheritInvariant]
-# flags: --enable-incomplete-feature=NewGenericSyntax
+[case testPEP695InferVarianceUnderscorePrefix]
+class Covariant1[T]:
+    def __init__(self, x: T) -> None:
+        self._x = x
+
+    @property
+    def x(self) -> T:
+        return self._x
+
+co1_1: Covariant1[float] = Covariant1[int](1)
+co1_2: Covariant1[int] = Covariant1[float](1)  # E: Incompatible types in assignment (expression has type "Covariant1[float]", variable has type "Covariant1[int]")
+
+class Covariant2[T]:
+    def __init__(self, x: T) -> None:
+        self.__foo_bar = x
+
+    @property
+    def x(self) -> T:
+        return self.__foo_bar
+
+co2_1: Covariant2[float] = Covariant2[int](1)
+co2_2: Covariant2[int] = Covariant2[float](1)  # E: Incompatible types in assignment (expression has type "Covariant2[float]", variable has type "Covariant2[int]")
+
+class Invariant1[T]:
+    def __init__(self, x: T) -> None:
+        self._x = x
+
+    # Methods behave differently from attributes
+    def _f(self, x: T) -> None: ...
+
+    @property
+    def x(self) -> T:
+        return self._x
+
+inv1_1: Invariant1[float] = Invariant1[int](1)  # E: Incompatible types in assignment (expression has type "Invariant1[int]", variable has type "Invariant1[float]")
+inv1_2: Invariant1[int] = Invariant1[float](1)  # E: Incompatible types in assignment (expression has type "Invariant1[float]", variable has type "Invariant1[int]")
+
+class Invariant2[T]:
+    def __init__(self, x: T) -> None:
+        # Dunders are special
+        self.__x__ = x
+
+    @property
+    def x(self) -> T:
+        return self.__x__
+
+inv2_1: Invariant2[float] = Invariant2[int](1)  # E: Incompatible types in assignment (expression has type "Invariant2[int]", variable has type "Invariant2[float]")
+inv2_2: Invariant2[int] = Invariant2[float](1)  # E: Incompatible types in assignment (expression has type "Invariant2[float]", variable has type "Invariant2[int]")
+
+class Invariant3[T]:
+    def __init__(self, x: T) -> None:
+        self._x = Invariant1(x)
+
+    @property
+    def x(self) -> T:
+        return self._x._x
+
+inv3_1: Invariant3[float] = Invariant3[int](1)  # E: Incompatible types in assignment (expression has type "Invariant3[int]", variable has type "Invariant3[float]")
+inv3_2: Invariant3[int] = Invariant3[float](1)  # E: Incompatible types in assignment (expression has type "Invariant3[float]", variable has type "Invariant3[int]")
+[builtins fixtures/property.pyi]
+
+[case testPEP695InferVarianceWithInheritedSelf]
+from typing import overload, Self, TypeVar, Generic
+
+T = TypeVar("T")
+S = TypeVar("S")
+
+class C(Generic[T]):
+    def f(self, x: T) -> Self: ...
+    def g(self) -> T: ...
+
+class D[T1, T2](C[T1]):
+    def m(self, x: T2) -> None: ...
+
+a1: D[int, int] = D[int, object]()
+a2: D[int, object] = D[int, int]()  # E: Incompatible types in assignment (expression has type "D[int, int]", variable has type "D[int, object]")
+a3: D[int, int] = D[object, object]()  # E: Incompatible types in assignment (expression has type "D[object, object]", variable has type "D[int, int]")
+a4: D[object, int] = D[int, object]()  # E: Incompatible types in assignment (expression has type "D[int, object]", variable has type "D[object, int]")
+
+[case testPEP695InferVarianceWithReturnSelf]
+from typing import Self, overload
+
+class Cov[T]:
+    def f(self) -> Self: ...
+
+a1: Cov[int] = Cov[float]()  # E: Incompatible types in assignment (expression has type "Cov[float]", variable has type "Cov[int]")
+a2: Cov[float] = Cov[int]()
+
+class Contra[T]:
+    def f(self) -> Self: ...
+    def g(self, x: T) -> None: ...
+
+b1: Contra[int] = Contra[float]()
+b2: Contra[float] = Contra[int]()  # E: Incompatible types in assignment (expression has type "Contra[int]", variable has type "Contra[float]")
 
+class Cov2[T]:
+    @overload
+    def f(self, x): ...
+    @overload
+    def f(self) -> Self: ...
+    def f(self, x=None): ...
+
+c1: Cov2[int] = Cov2[float]()  # E: Incompatible types in assignment (expression has type "Cov2[float]", variable has type "Cov2[int]")
+c2: Cov2[float] = Cov2[int]()
+
+class Contra2[T]:
+    @overload
+    def f(self, x): ...
+    @overload
+    def f(self) -> Self: ...
+    def f(self, x=None): ...
+
+    def g(self, x: T) -> None: ...
+
+d1: Contra2[int] = Contra2[float]()
+d2: Contra2[float] = Contra2[int]()  # E: Incompatible types in assignment (expression has type "Contra2[int]", variable has type "Contra2[float]")
+
+[case testPEP695InheritInvariant]
 class Invariant[T]:
     x: T
 
@@ -366,7 +471,6 @@ if int():
     b = a  # E: Incompatible types in assignment (expression has type "Subclass[int]", variable has type "Subclass[object]")
 
 [case testPEP695InheritanceMakesInvariant]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 class Covariant[T]:
     def f(self) -> T:
         ...
@@ -381,7 +485,6 @@ a: Subclass[int] = Subclass[object]()  # E: Incompatible types in assignment (ex
 b: Subclass[object] = Subclass[int]()  # E: Incompatible types in assignment (expression has type "Subclass[int]", variable has type "Subclass[object]")
 
 [case testPEP695InheritCoOrContravariant]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 class Contravariant[T]:
     def f(self, x: T) -> None: pass
 
@@ -407,7 +510,6 @@ e: InvSubclass[int] = InvSubclass[object]()  # E: Incompatible types in assignme
 f: InvSubclass[object] = InvSubclass[int]()  # E: Incompatible types in assignment (expression has type "InvSubclass[int]", variable has type "InvSubclass[object]")
 
 [case testPEP695FinalAttribute]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from typing import Final
 
 class C[T]:
@@ -418,8 +520,6 @@ a: C[int] = C[object](1)  # E: Incompatible types in assignment (expression has
 b: C[object] = C[int](1)
 
 [case testPEP695TwoTypeVariables]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class C[T, S]:
     def f(self, x: T) -> None: ...
     def g(self) -> S: ...
@@ -430,8 +530,6 @@ c: C[int, int] = C[int, object]()  # E: Incompatible types in assignment (expres
 d: C[int, object] = C[int, int]()
 
 [case testPEP695Properties]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class R[T]:
     @property
     def p(self) -> T: ...
@@ -449,7 +547,6 @@ d: RW[object] = RW[int]()  # E: Incompatible types in assignment (expression has
 [builtins fixtures/property.pyi]
 
 [case testPEP695Protocol]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from typing import Protocol
 
 class PContra[T](Protocol):
@@ -486,8 +583,6 @@ if int():
     f = e  # E: Incompatible types in assignment (expression has type "PInv[int]", variable has type "PInv[object]")
 
 [case testPEP695TypeAlias]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class C[T]: pass
 class D[T, S]: pass
 
@@ -509,15 +604,45 @@ a4: A4
 reveal_type(a4)  # N: Revealed type is "Union[builtins.int, builtins.str]"
 [builtins fixtures/type.pyi]
 
+[case testPEP695TypeAliasNotValidAsBaseClass]
+from typing import TypeAlias
+
+import m
+
+type A1 = int
+class Bad1(A1):  # E: Type alias defined using "type" statement not valid as base class
+    pass
+
+type A2[T] = list[T]
+class Bad2(A2[int]):  # E: Type alias defined using "type" statement not valid as base class
+    pass
+
+class Bad3(m.A1):  # E: Type alias defined using "type" statement not valid as base class
+    pass
+
+class Bad4(m.A2[int]):  # E: Type alias defined using "type" statement not valid as base class
+    pass
+
+B1 = int
+B2 = list
+B3: TypeAlias = int
+class Good1(B1): pass
+class Good2(B2[int]): pass
+class Good3(list[A1]): pass
+class Good4(list[A2[int]]): pass
+class Good5(B3): pass
+
+[file m.py]
+type A1 = str
+type A2[T] = list[T]
+[typing fixtures/typing-medium.pyi]
+
 [case testPEP695TypeAliasWithUnusedTypeParams]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 type A[T] = int
 a: A[str]
 reveal_type(a)  # N: Revealed type is "builtins.int"
 
 [case testPEP695TypeAliasForwardReference1]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 type A[T] = C[T]
 
 a: A[int]
@@ -526,8 +651,6 @@ reveal_type(a)  # N: Revealed type is "__main__.C[builtins.int]"
 class C[T]: pass
 
 [case testPEP695TypeAliasForwardReference2]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 type X = C
 type A = X
 
@@ -539,8 +662,6 @@ class C: pass
 [typing fixtures/typing-full.pyi]
 
 [case testPEP695TypeAliasForwardReference3]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 type X = D
 type A = C[X]
 
@@ -551,13 +672,9 @@ class C[T]: pass
 class D: pass
 
 [case testPEP695TypeAliasForwardReference4]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 type A = C
 
-# Note that this doesn't actually work at runtime, but we currently don't
-# keep track whether a type alias is valid in various runtime type contexts.
-class D(A):
+class D(A):  # E: Type alias defined using "type" statement not valid as base class
     pass
 
 class C: pass
@@ -566,7 +683,6 @@ x: C = D()
 y: D = C()  # E: Incompatible types in assignment (expression has type "C", variable has type "D")
 
 [case testPEP695TypeAliasForwardReference5]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 type A = str
 type B[T] = C[T]
 class C[T]: pass
@@ -578,13 +694,11 @@ reveal_type(b)  # N: Revealed type is "__main__.C[builtins.int]"
 reveal_type(c)  # N: Revealed type is "__main__.C[builtins.str]"
 
 [case testPEP695TypeAliasWithUndefineName]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 type A[T] = XXX  # E: Name "XXX" is not defined
 a: A[int]
 reveal_type(a)  # N: Revealed type is "Any"
 
 [case testPEP695TypeAliasInvalidType]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 type A = int | 1  # E: Invalid type: try using Literal[1] instead?
 
 a: A
@@ -595,13 +709,10 @@ reveal_type(b)  # N: Revealed type is "Any"
 [builtins fixtures/type.pyi]
 
 [case testPEP695TypeAliasBoundForwardReference]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 type B[T: Foo] = list[T]
 class Foo: pass
 
 [case testPEP695UpperBound]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class D:
     x: int
 class E(D): pass
@@ -624,8 +735,6 @@ reveal_type(f(E()))  # N: Revealed type is "__main__.E"
 f(1)  # E: Value of type variable "T" of "f" cannot be "int"
 
 [case testPEP695UpperBoundForwardReference1]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class C[T: D]: pass
 
 a: C[D]
@@ -639,8 +748,6 @@ class D: pass
 class E(D): pass
 
 [case testPEP695UpperBoundForwardReference2]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 type A = D
 class C[T: A]: pass
 
@@ -655,8 +762,6 @@ reveal_type(b)  # N: Revealed type is "__main__.C[__main__.E]"
 c: C[int]  # E: Type argument "int" of "C" must be a subtype of "D"
 
 [case testPEP695UpperBoundForwardReference3]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class D[T]: pass
 class E[T](D[T]): pass
 
@@ -674,8 +779,6 @@ reveal_type(b)  # N: Revealed type is "__main__.C[__main__.E[__main__.X]]"
 c: C[D[int]]  # E: Type argument "D[int]" of "C" must be a subtype of "D[X]"
 
 [case testPEP695UpperBoundForwardReference4]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 def f[T: D](a: T) -> T:
     reveal_type(a.x)  # N: Revealed type is "builtins.int"
     return a
@@ -689,8 +792,6 @@ reveal_type(f(E()))  # N: Revealed type is "__main__.E"
 f(1)  # E: Value of type variable "T" of "f" cannot be "int"
 
 [case testPEP695UpperBoundUndefinedName]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class C[T: XX]:  # E: Name "XX" is not defined
     pass
 
@@ -701,8 +802,6 @@ def f[T: YY](x: T) -> T:  # E: Name "YY" is not defined
 reveal_type(f)  # N: Revealed type is "def [T <: Any] (x: T`-1) -> T`-1"
 
 [case testPEP695UpperBoundWithMultipleParams]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class C[T, S: int]: pass
 class D[A: int, B]: pass
 
@@ -720,8 +819,6 @@ f('x', None)  # E: Value of type variable "T" of "f" cannot be "str" \
               # E: Value of type variable "S" of "f" cannot be "None"
 
 [case testPEP695InferVarianceOfTupleType]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class Cov[T](tuple[int, str]):
     def f(self) -> T: pass
 
@@ -741,9 +838,7 @@ e: Contra[int] = Contra[object]()
 f: Contra[object] = Contra[int]()  # E: Incompatible types in assignment (expression has type "Contra[int]", variable has type "Contra[object]")
 [builtins fixtures/tuple-simple.pyi]
 
-[case testPEP695ValueRestiction]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
+[case testPEP695ValueRestriction]
 def f[T: (int, str)](x: T) -> T:
     reveal_type(x)  # N: Revealed type is "builtins.int" \
                     # N: Revealed type is "builtins.str"
@@ -759,9 +854,7 @@ a: C[object]
 b: C[None]
 c: C[int]  # E: Value of type variable "T" of "C" cannot be "int"
 
-[case testPEP695ValueRestictionForwardReference]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
+[case testPEP695ValueRestrictionForwardReference]
 class C[T: (int, D)]:
     def __init__(self, x: T) -> None:
         a = x
@@ -777,9 +870,7 @@ class D: pass
 
 C(D())
 
-[case testPEP695ValueRestictionUndefinedName]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
+[case testPEP695ValueRestrictionUndefinedName]
 class C[T: (int, XX)]:  # E: Name "XX" is not defined
     pass
 
@@ -787,7 +878,6 @@ def f[S: (int, YY)](x: S) -> S:  # E: Name "YY" is not defined
     return x
 
 [case testPEP695ParamSpec]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from typing import Callable
 
 def g[**P](f: Callable[P, None], *args: P.args, **kwargs: P.kwargs) -> None:
@@ -809,7 +899,6 @@ reveal_type(a.m)  # N: Revealed type is "def (builtins.int, builtins.str)"
 [builtins fixtures/tuple.pyi]
 
 [case testPEP695ParamSpecTypeAlias]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from typing import Callable
 
 type C[**P] = Callable[P, int]
@@ -820,8 +909,6 @@ reveal_type(f)  # N: Revealed type is "def (builtins.str, Union[builtins.int, No
 [typing fixtures/typing-full.pyi]
 
 [case testPEP695TypeVarTuple]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 def f[*Ts](t: tuple[*Ts]) -> tuple[*Ts]:
     reveal_type(t)  # N: Revealed type is "Tuple[Unpack[Ts`-1]]"
     return t
@@ -841,7 +928,6 @@ b = c  # E: Incompatible types in assignment (expression has type "C[str]", vari
 [builtins fixtures/tuple.pyi]
 
 [case testPEP695TypeVarTupleAlias]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from typing import Callable
 
 type C[*Ts] = tuple[*Ts, int]
@@ -851,7 +937,6 @@ reveal_type(a)  # N: Revealed type is "Tuple[builtins.str, None, builtins.int]"
 [builtins fixtures/tuple.pyi]
 
 [case testPEP695IncrementalFunction]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 import a
 
 [file a.py]
@@ -878,7 +963,6 @@ tmp/a.py:4: error: Value of type variable "T" of "g" cannot be "str"
 tmp/a.py:5: error: Value of type variable "S" of "g" cannot be "int"
 
 [case testPEP695IncrementalClass]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 import a
 
 [file a.py]
@@ -911,7 +995,6 @@ tmp/a.py:12: error: Value of type variable "S" of "D" cannot be "SS"
 tmp/a.py:13: error: Type argument "object" of "D" must be a subtype of "int"
 
 [case testPEP695IncrementalParamSpecAndTypeVarTuple]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 import a
 
 [file a.py]
@@ -935,7 +1018,6 @@ class D[**P]:
 tmp/a.py:6: note: Revealed type is "def (builtins.int, builtins.str)"
 
 [case testPEP695IncrementalTypeAlias]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 import a
 
 [file a.py]
@@ -959,8 +1041,6 @@ tmp/a.py:3: note: Revealed type is "builtins.str"
 tmp/a.py:5: note: Revealed type is "b.Foo[builtins.int]"
 
 [case testPEP695UndefinedNameInGenericFunction]
-# mypy: enable-incomplete-feature=NewGenericSyntax
-
 def f[T](x: T) -> T:
     return unknown()  # E: Name "unknown" is not defined
 
@@ -969,7 +1049,6 @@ class C:
         return unknown()  # E: Name "unknown" is not defined
 
 [case testPEP695FunctionTypeVarAccessInFunction]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 from typing import cast
 
 class C:
@@ -981,8 +1060,6 @@ class C:
 reveal_type(C().m(1))  # N: Revealed type is "builtins.int"
 
 [case testPEP695ScopingBasics]
-# mypy: enable-incomplete-feature=NewGenericSyntax
-
 T = 1
 
 def f[T](x: T) -> T:
@@ -999,8 +1076,6 @@ class C[T]:
 reveal_type(T)  # N: Revealed type is "builtins.int"
 
 [case testPEP695ClassScoping]
-# mypy: enable-incomplete-feature=NewGenericSyntax
-
 class C:
     class D: pass
 
@@ -1011,7 +1086,6 @@ C().m(C.D(), C.D())
 C().m(1, C.D())  # E: Value of type variable "T" of "m" of "C" cannot be "int"
 
 [case testPEP695NestedGenericFunction]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 def f[T](x: T) -> T:
     reveal_type(f(x))  # N: Revealed type is "T`-1"
     reveal_type(f(1))  # N: Revealed type is "builtins.int"
@@ -1035,7 +1109,6 @@ def f[T](x: T) -> T:
     return x
 
 [case testPEP695NonLocalAndGlobal]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 def f() -> None:
     T = 1
     def g[T](x: T) -> T:
@@ -1065,7 +1138,6 @@ class C[T]:
         return a
 
 [case testPEP695ArgumentDefault]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 from typing import cast
 
 def f[T](
@@ -1085,7 +1157,6 @@ class C:
 [typing fixtures/typing-full.pyi]
 
 [case testPEP695ListComprehension]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 from typing import cast
 
 def f[T](x: T) -> T:
@@ -1094,8 +1165,6 @@ def f[T](x: T) -> T:
     return x
 
 [case testPEP695ReuseNameInSameScope]
-# mypy: enable-incomplete-feature=NewGenericSyntax
-
 class C[T]:
     def m[S](self, x: S, y: T) -> S | T:
         return x
@@ -1117,7 +1186,6 @@ def g[T](x: T) -> T:
     return x
 
 [case testPEP695NestedScopingSpecialCases]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 # This is adapted from PEP 695
 S = 0
 
@@ -1134,7 +1202,6 @@ def outer1[S]() -> None:
             global S
 
 [case testPEP695ScopingWithBaseClasses]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 # This is adapted from PEP 695
 class Outer:
     class Private:
@@ -1150,7 +1217,6 @@ class Outer:
         return a
 
 [case testPEP695RedefineTypeParameterInScope]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 class C[T]:
     def m[T](self, x: T) -> T:  # E: "T" already defined as a type parameter
         return x
@@ -1162,7 +1228,6 @@ def f[S, S](x: S) -> S:  # E: "S" already defined as a type parameter
     return x
 
 [case testPEP695ClassDecorator]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 from typing import Any
 
 T = 0
@@ -1174,8 +1239,6 @@ class C[T]:
     pass
 
 [case testPEP695RecursiceTypeAlias]
-# mypy: enable-incomplete-feature=NewGenericSyntax
-
 type A = str | list[A]
 a: A
 reveal_type(a)  # N: Revealed type is "Union[builtins.str, builtins.list[...]]"
@@ -1188,8 +1251,6 @@ reveal_type(b)  # N: Revealed type is "Union[__main__.C[builtins.int], builtins.
 [builtins fixtures/type.pyi]
 
 [case testPEP695BadRecursiveTypeAlias]
-# mypy: enable-incomplete-feature=NewGenericSyntax
-
 type A = A  # E: Cannot resolve name "A" (possible cyclic definition)
 type B = B | int  # E: Invalid recursive alias: a union item of itself
 a: A
@@ -1200,8 +1261,6 @@ reveal_type(b)  # N: Revealed type is "Any"
 [typing fixtures/typing-full.pyi]
 
 [case testPEP695RecursiveTypeAliasForwardReference]
-# mypy: enable-incomplete-feature=NewGenericSyntax
-
 def f(a: A) -> None:
     if isinstance(a, str):
         reveal_type(a)  # N: Revealed type is "builtins.str"
@@ -1220,7 +1279,6 @@ f(C[int]())  # E: Argument 1 to "f" has incompatible type "C[int]"; expected "A"
 [builtins fixtures/isinstance.pyi]
 
 [case testPEP695InvalidGenericOrProtocolBaseClass]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 from typing import Generic, Protocol, TypeVar
 
 S = TypeVar("S")
@@ -1238,8 +1296,14 @@ class P[T](Protocol[T]):  # E: No arguments expected for "Protocol" base class
 class P2[T](Protocol[S]):  # E: No arguments expected for "Protocol" base class
     pass
 
+[case testPEP695CannotUseTypeVarFromOuterClass]
+class ClassG[V]:
+    # This used to crash
+    class ClassD[T: dict[str, V]]:  # E: Name "V" is not defined
+        ...
+[builtins fixtures/dict.pyi]
+
 [case testPEP695MixNewAndOldStyleGenerics]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 from typing import TypeVar
 
 S = TypeVar("S")
@@ -1260,7 +1324,6 @@ class D[T](C[S]):  # E: All type parameters should be declared ("S" not declared
     pass
 
 [case testPEP695MixNewAndOldStyleTypeVarTupleAndParamSpec]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 from typing import TypeVarTuple, ParamSpec, Callable
 Ts = TypeVarTuple("Ts")
 P = ParamSpec("P")
@@ -1272,7 +1335,6 @@ def g[T](x: T, f: tuple[*Ts]  # E: All type parameters should be declared ("Ts"
 [builtins fixtures/tuple.pyi]
 
 [case testPEP695MixNewAndOldStyleGenericsInTypeAlias]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 from typing import TypeVar, ParamSpec, TypeVarTuple, Callable
 
 T = TypeVar("T")
@@ -1289,7 +1351,6 @@ type C = Callable[P, None]  # E: All type parameters should be declared ("P" not
 [typing fixtures/typing-full.pyi]
 
 [case testPEP695NonGenericAliasToGenericClass]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 class C[T]: pass
 type A = C
 x: C
@@ -1299,7 +1360,6 @@ reveal_type(y)  # N: Revealed type is "__main__.C[Any]"
 z: A[int]  # E: Bad number of arguments for type alias, expected 0, given 1
 
 [case testPEP695SelfType]
-# mypy: enable-incomplete-feature=NewGenericSyntax
 from typing import Self
 
 class C:
@@ -1330,8 +1390,6 @@ reveal_type(F[str]().mm(b'x'))  # N: Revealed type is "Tuple[__main__.F[builtins
 [builtins fixtures/tuple.pyi]
 
 [case testPEP695CallAlias]
-# mypy: enable-incomplete-feature=NewGenericSyntax
-
 class C:
     def __init__(self, x: str) -> None: ...
 type A = C
@@ -1354,7 +1412,6 @@ B2[int]()
 [typing fixtures/typing-full.pyi]
 
 [case testPEP695IncrementalTypeAliasKinds]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 import a
 
 [file a.py]
@@ -1377,7 +1434,6 @@ C: TypeAlias = int
 tmp/a.py:2: error: "TypeAliasType" not callable
 
 [case testPEP695TypeAliasBoundAndValueChecking]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from typing import Any, cast
 
 class C: pass
@@ -1418,8 +1474,6 @@ c4: A3[int, str]  # E: Type argument "int" of "A3" must be a subtype of "C"
 [typing fixtures/typing-full.pyi]
 
 [case testPEP695TypeAliasInClassBodyOrFunction]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 class C:
     type A = int
     type B[T] = list[T] | None
@@ -1472,16 +1526,14 @@ reveal_type(E[str]().a)  # N: Revealed type is "builtins.list[Any]"
 [typing fixtures/typing-full.pyi]
 
 [case testPEP695RedefineAsTypeAlias1]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 class C: pass
-type C = int  # E: Name "C" already defined on line 2
+type C = int  # E: Name "C" already defined on line 1
 
 A = 0
-type A = str  # E: Name "A" already defined on line 5
+type A = str  # E: Name "A" already defined on line 4
 reveal_type(A)  # N: Revealed type is "builtins.int"
 
 [case testPEP695RedefineAsTypeAlias2]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from m import D
 type D = int  # E: Name "D" already defined (possibly by an import)
 a: D
@@ -1490,30 +1542,26 @@ reveal_type(a)  # N: Revealed type is "m.D"
 class D: pass
 
 [case testPEP695RedefineAsTypeAlias3]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 D = list["Forward"]
-type D = int  # E: Name "D" already defined on line 2
+type D = int  # E: Name "D" already defined on line 1
 Forward = str
 x: D
 reveal_type(x)  # N: Revealed type is "builtins.list[builtins.str]"
 
 [case testPEP695MultiDefinitionsForTypeAlias]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 if int():
     type A[T] = list[T]
 else:
-    type A[T] = str  # E: Name "A" already defined on line 3
+    type A[T] = str  # E: Name "A" already defined on line 2
 x: T  # E: Name "T" is not defined
 a: A[int]
 reveal_type(a)  # N: Revealed type is "builtins.list[builtins.int]"
 
 [case testPEP695UndefinedNameInAnnotation]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 def f[T](x: foobar, y: T) -> T: ...  # E: Name "foobar" is not defined
 reveal_type(f)  # N: Revealed type is "def [T] (x: Any, y: T`-1) -> T`-1"
 
 [case testPEP695WrongNumberOfConstrainedTypes]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 type A[T: ()] = list[T]  # E: Type variable must have at least two constrained types
 a: A[int]
 reveal_type(a)  # N: Revealed type is "builtins.list[builtins.int]"
@@ -1523,7 +1571,6 @@ b: B[str]
 reveal_type(b)  # N: Revealed type is "builtins.list[builtins.str]"
 
 [case testPEP695UsingTypeVariableInOwnBoundOrConstraint]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 type A[T: list[T]] = str  # E: Name "T" is not defined
 type B[S: (list[S], str)] = str  # E: Name "S" is not defined
 type C[T, S: list[T]] = str  # E: Name "T" is not defined
@@ -1533,7 +1580,6 @@ class D[T: T]:  # E: Name "T" is not defined
     pass
 
 [case testPEP695InvalidType]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 def f[T: 1](x: T) -> T: ...  # E: Invalid type: try using Literal[1] instead?
 class C[T: (int, (1 + 2))]: pass  # E: Invalid type comment or annotation
 type A = list[1]  # E: Invalid type: try using Literal[1] instead?
@@ -1544,7 +1590,6 @@ b: B
 reveal_type(b)  # N: Revealed type is "Any"
 
 [case testPEP695GenericNamedTuple]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from typing import NamedTuple
 
 # Invariant because of the signature of the generated _replace method
@@ -1571,7 +1616,6 @@ e: M[bool]  # E: Value of type variable "T" of "M" cannot be "bool"
 [builtins fixtures/tuple.pyi]
 
 [case testPEP695GenericTypedDict]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from typing import TypedDict
 
 class D[T](TypedDict):
@@ -1592,7 +1636,6 @@ d: E[int]  # E: Type argument "int" of "E" must be a subtype of "str"
 [typing fixtures/typing-full.pyi]
 
 [case testCurrentClassWorksAsBound]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from typing import Protocol
 
 class Comparable[T: Comparable](Protocol):
@@ -1605,7 +1648,6 @@ x: Comparable[Good]
 y: Comparable[int]  # E: Type argument "int" of "Comparable" must be a subtype of "Comparable[Any]"
 
 [case testPEP695TypeAliasWithDifferentTargetTypes]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 import types  # We need GenericAlias from here, and test stubs don't bring in 'types'
 from typing import Any, Callable, List, Literal, TypedDict
 
@@ -1657,7 +1699,7 @@ type I3 = None | C[TD]
 [typing fixtures/typing-full.pyi]
 
 [case testTypedDictInlineYesNewStyleAlias]
-# flags: --enable-incomplete-feature=NewGenericSyntax --enable-incomplete-feature=InlineTypedDict
+# flags: --enable-incomplete-feature=InlineTypedDict
 type X[T] = {"item": T, "other": X[T] | None}
 x: X[str]
 reveal_type(x)  # N: Revealed type is "TypedDict({'item': builtins.str, 'other': Union[..., None]})"
@@ -1669,8 +1711,6 @@ type Y[T] = {"item": T, **Y[T]}  # E: Overwriting TypedDict field "item" while m
 [typing fixtures/typing-full.pyi]
 
 [case testPEP695UsingIncorrectExpressionsInTypeVariableBound]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 type X[T: (yield 1)] = Any  # E: Yield expression cannot be used as a type variable bound
 type Y[T: (yield from [])] = Any # E: Yield expression cannot be used as a type variable bound
 type Z[T: (a := 1)] = Any  # E: Named expression cannot be used as a type variable bound
@@ -1702,8 +1742,6 @@ def fooz_nested[T: (1 + (a := 1))](): pass  # E: Named expression cannot be used
 def fook_nested[T: (1 +(await 1))](): pass  # E: Await expression cannot be used as a type variable bound
 
 [case testPEP695UsingIncorrectExpressionsInTypeAlias]
-# flags: --enable-incomplete-feature=NewGenericSyntax
-
 type X = (yield 1)  # E: Yield expression cannot be used within a type alias
 type Y = (yield from []) # E: Yield expression cannot be used within a type alias
 type Z = (a := 1)  # E: Named expression cannot be used within a type alias
@@ -1713,3 +1751,125 @@ type XNested = (1 + (yield 1))  # E: Yield expression cannot be used within a ty
 type YNested = (1 + (yield from [])) # E: Yield expression cannot be used within a type alias
 type ZNested = (1 + (a := 1))  # E: Named expression cannot be used within a type alias
 type KNested = (1 + (await 1))  # E: Await expression cannot be used within a type alias
+
+[case testPEP695TypeAliasAndAnnotated]
+from typing_extensions import Annotated, Annotated as _Annotated
+import typing_extensions as t
+
+def ann(*args): ...
+
+type A = Annotated[int, ann()]
+type B = Annotated[int | str, ann((1, 2))]
+type C = _Annotated[int, ann()]
+type D = t.Annotated[str, ann()]
+
+x: A
+y: B
+z: C
+zz: D
+reveal_type(x)  # N: Revealed type is "builtins.int"
+reveal_type(y)  # N: Revealed type is "Union[builtins.int, builtins.str]"
+reveal_type(z)  # N: Revealed type is "builtins.int"
+reveal_type(zz)  # N: Revealed type is "builtins.str"
+[builtins fixtures/tuple.pyi]
+
+[case testPEP695NestedGenericClass1]
+class C[T]:
+    def f(self) -> T: ...
+
+class A:
+    class B[Q]:
+        def __init__(self, a: Q) -> None:
+            self.a = a
+
+        def f(self) -> Q:
+            return self.a
+
+        def g(self, x: Q) -> None: ...
+
+    b: B[str]
+
+x: A.B[int]
+x.g("x")  # E: Argument 1 to "g" of "B" has incompatible type "str"; expected "int"
+reveal_type(x.a)  # N: Revealed type is "builtins.int"
+reveal_type(x)  # N: Revealed type is "__main__.A.B[builtins.int]"
+reveal_type(A.b)  # N: Revealed type is "__main__.A.B[builtins.str]"
+
+[case testPEP695NestedGenericClass2]
+class A:
+    def m(self) -> None:
+        class B[T]:
+            def f(self) -> T: ...
+        x: B[int]
+        reveal_type(x.f())  # N: Revealed type is "builtins.int"
+        self.a = B[str]()
+
+reveal_type(A().a)  # N: Revealed type is "__main__.B@3[builtins.str]"
+reveal_type(A().a.f())  # N: Revealed type is "builtins.str"
+
+[case testPEP695NestedGenericClass3]
+class C[T]:
+    def f(self) -> T: ...
+    class D[S]:
+        x: T  # E: Name "T" is not defined
+        def g(self) -> S: ...
+
+a: C[int]
+reveal_type(a.f())  # N: Revealed type is "builtins.int"
+b: C.D[str]
+reveal_type(b.g())  # N: Revealed type is "builtins.str"
+
+class E[T]:
+    class F[T]:  # E: "T" already defined as a type parameter
+        x: T
+
+c: E.F[int]
+
+[case testPEP695NestedGenericClass4]
+class A:
+    class B[T]:
+        def __get__(self, instance: A, owner: type[A]) -> T:
+            return None  # E: Incompatible return value type (got "None", expected "T")
+    f = B[int]()
+
+a = A()
+v = a.f
+
+[case testPEP695VarianceInheritedFromBaseWithExplicitVariance]
+from typing import TypeVar, Generic
+
+T = TypeVar("T")
+
+class ParentInvariant(Generic[T]):
+    pass
+
+class Invariant1[T](ParentInvariant[T]):
+    pass
+
+a1: Invariant1[int] = Invariant1[float]()  # E: Incompatible types in assignment (expression has type "Invariant1[float]", variable has type "Invariant1[int]")
+a2: Invariant1[float] = Invariant1[int]()  # E: Incompatible types in assignment (expression has type "Invariant1[int]", variable has type "Invariant1[float]")
+
+T_contra = TypeVar("T_contra", contravariant=True)
+
+class ParentContravariant(Generic[T_contra]):
+    pass
+
+class Contravariant[T](ParentContravariant[T]):
+    pass
+
+b1: Contravariant[int] = Contravariant[float]()
+b2: Contravariant[float] = Contravariant[int]()  # E: Incompatible types in assignment (expression has type "Contravariant[int]", variable has type "Contravariant[float]")
+
+class Invariant2[T](ParentContravariant[T]):
+    def f(self) -> T: ...
+
+c1: Invariant2[int] = Invariant2[float]()  # E: Incompatible types in assignment (expression has type "Invariant2[float]", variable has type "Invariant2[int]")
+c2: Invariant2[float] = Invariant2[int]()  # E: Incompatible types in assignment (expression has type "Invariant2[int]", variable has type "Invariant2[float]")
+
+class Multi[T, S](ParentInvariant[T], ParentContravariant[S]):
+    pass
+
+d1: Multi[int, str] = Multi[float, str]()  # E: Incompatible types in assignment (expression has type "Multi[float, str]", variable has type "Multi[int, str]")
+d2: Multi[float, str] = Multi[int, str]()  # E: Incompatible types in assignment (expression has type "Multi[int, str]", variable has type "Multi[float, str]")
+d3: Multi[str, int] = Multi[str, float]()
+d4: Multi[str, float] = Multi[str, int]()  # E: Incompatible types in assignment (expression has type "Multi[str, int]", variable has type "Multi[str, float]")
diff --git a/test-data/unit/check-python38.test b/test-data/unit/check-python38.test
index dfb918defb0a..199014a66fed 100644
--- a/test-data/unit/check-python38.test
+++ b/test-data/unit/check-python38.test
@@ -463,9 +463,9 @@ def check_partial_list() -> None:
 if (x := 0):
     reveal_type(x)  # E: Statement is unreachable
 else:
-    reveal_type(x)  # N: Revealed type is "builtins.int"
+    reveal_type(x)  # N: Revealed type is "Literal[0]"
 
-reveal_type(x)  # N: Revealed type is "builtins.int"
+reveal_type(x)  # N: Revealed type is "Literal[0]"
 
 [case testWalrusAssignmentAndConditionScopeForProperty]
 # flags: --warn-unreachable
@@ -483,7 +483,7 @@ wrapper = PropertyWrapper()
 if x := wrapper.f:
     reveal_type(x)  # N: Revealed type is "builtins.str"
 else:
-    reveal_type(x)  # N: Revealed type is "builtins.str"
+    reveal_type(x)  # N: Revealed type is "Literal['']"
 
 reveal_type(x)  # N: Revealed type is "builtins.str"
 
@@ -505,7 +505,7 @@ def f() -> str: ...
 if x := f():
     reveal_type(x)  # N: Revealed type is "builtins.str"
 else:
-    reveal_type(x)  # N: Revealed type is "builtins.str"
+    reveal_type(x)  # N: Revealed type is "Literal['']"
 
 reveal_type(x)  # N: Revealed type is "builtins.str"
 
diff --git a/test-data/unit/deps.test b/test-data/unit/deps.test
index 3364dee6c696..84cea99bf2f6 100644
--- a/test-data/unit/deps.test
+++ b/test-data/unit/deps.test
@@ -1433,7 +1433,7 @@ class B(A):
 <dataclasses> -> m
 
 [case testPEP695TypeAliasDeps]
-# flags: --enable-incomplete-feature=NewGenericSyntax --python-version=3.12
+# flags: --python-version=3.12
 from a import C, E
 type A = C
 type A2 = A
diff --git a/test-data/unit/diff.test b/test-data/unit/diff.test
index 9212d902e8b2..10fb0a80cf38 100644
--- a/test-data/unit/diff.test
+++ b/test-data/unit/diff.test
@@ -1532,7 +1532,7 @@ __main__.C.get_by_team_and_id
 __main__.Optional
 
 [case testPEP695TypeAlias]
-# flags: --enable-incomplete-feature=NewGenericSyntax --python-version=3.12
+# flags: --python-version=3.12
 from typing_extensions import TypeAlias, TypeAliasType
 type A = int
 type B = str
@@ -1544,7 +1544,7 @@ G = TypeAliasType("G", int)
 type H = int
 
 [file next.py]
-# flags: --enable-incomplete-feature=NewGenericSyntax --python-version=3.12
+# flags: --python-version=3.12
 from typing_extensions import TypeAlias, TypeAliasType
 type A = str
 type B = str
@@ -1566,7 +1566,7 @@ __main__.G
 __main__.H
 
 [case testPEP695TypeAlias2]
-# flags: --enable-incomplete-feature=NewGenericSyntax --python-version=3.12
+# flags: --python-version=3.12
 type A[T: int] = list[T]
 type B[T: int] = list[T]
 type C[T: (int, str)] = list[T]
@@ -1575,7 +1575,7 @@ type E[T: int] = list[T]
 type F[T: (int, str)] = list[T]
 
 [file next.py]
-# flags: --enable-incomplete-feature=NewGenericSyntax --python-version=3.12
+# flags: --python-version=3.12
 type A[T] = list[T]
 type B[T: str] = list[T]
 type C[T: (int, None)] = list[T]
@@ -1590,13 +1590,13 @@ __main__.C
 __main__.D
 
 [case testPEP695GenericFunction]
-# flags: --enable-incomplete-feature=NewGenericSyntax --python-version=3.12
+# flags: --python-version=3.12
 def f[T](x: T) -> T:
     return x
 def g[T](x: T, y: T) -> T:
     return x
 [file next.py]
-# flags: --enable-incomplete-feature=NewGenericSyntax --python-version=3.12
+# flags: --python-version=3.12
 def f[T](x: T) -> T:
     return x
 def g[T, S](x: T, y: S) -> S:
@@ -1605,7 +1605,7 @@ def g[T, S](x: T, y: S) -> S:
 __main__.g
 
 [case testPEP695GenericClass]
-# flags: --enable-incomplete-feature=NewGenericSyntax --python-version=3.12
+# flags: --python-version=3.12
 class C[T]:
     pass
 class D[T]:
@@ -1615,7 +1615,7 @@ class E[T]:
 class F[T]:
     def f(self, x: object) -> T: ...
 [file next.py]
-# flags: --enable-incomplete-feature=NewGenericSyntax --python-version=3.12
+# flags: --python-version=3.12
 class C[T]:
     pass
 class D[T: int]:
diff --git a/test-data/unit/fine-grained-python312.test b/test-data/unit/fine-grained-python312.test
index 3970c8cacfbf..0e438ca06574 100644
--- a/test-data/unit/fine-grained-python312.test
+++ b/test-data/unit/fine-grained-python312.test
@@ -1,5 +1,4 @@
 [case testPEP695TypeAliasDep]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 import m
 def g() -> m.C:
     return m.f()
@@ -15,10 +14,9 @@ def f() -> int:
     pass
 [out]
 ==
-main:4: error: Incompatible return value type (got "int", expected "str")
+main:3: error: Incompatible return value type (got "int", expected "str")
 
 [case testPEP695ChangeOldStyleToNewStyleTypeAlias]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from m import A
 A()
 
@@ -31,10 +29,9 @@ type A = int
 [builtins fixtures/tuple.pyi]
 [out]
 ==
-main:3: error: "TypeAliasType" not callable
+main:2: error: "TypeAliasType" not callable
 
 [case testPEP695VarianceChangesDueToDependency]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from a import C
 
 x: C[object] = C[int]()
@@ -55,10 +52,9 @@ class A[T]:
 
 [out]
 ==
-main:4: error: Incompatible types in assignment (expression has type "C[int]", variable has type "C[object]")
+main:3: error: Incompatible types in assignment (expression has type "C[int]", variable has type "C[object]")
 
 [case testPEP695TypeAliasChangesDueToDependency]
-# flags: --enable-incomplete-feature=NewGenericSyntax
 from a import A
 x: A
 x = 0
@@ -78,5 +74,24 @@ from builtins import tuple as B
 [typing fixtures/typing-full.pyi]
 [out]
 ==
-main:4: error: Incompatible types in assignment (expression has type "int", variable has type "tuple[int, str]")
-main:5: error: Incompatible types in assignment (expression has type "str", variable has type "tuple[int, str]")
+main:3: error: Incompatible types in assignment (expression has type "int", variable has type "Tuple[int, str]")
+main:4: error: Incompatible types in assignment (expression has type "str", variable has type "Tuple[int, str]")
+
+[case testPEP695NestedGenericClassMethodUpdated]
+from a import f
+
+class C:
+    class D[T]:
+        x: T
+        def m(self) -> T:
+            f()
+            return self.x
+
+[file a.py]
+def f() -> None: pass
+
+[file a.py.2]
+def f(x: int) -> None: pass
+[out]
+==
+main:7: error: Missing positional argument "x" in call to "f"
diff --git a/test-data/unit/fixtures/tuple-simple.pyi b/test-data/unit/fixtures/tuple-simple.pyi
index 6c816c1c5b7a..07f9edf63cdd 100644
--- a/test-data/unit/fixtures/tuple-simple.pyi
+++ b/test-data/unit/fixtures/tuple-simple.pyi
@@ -5,7 +5,7 @@
 
 from typing import Iterable, TypeVar, Generic
 
-T = TypeVar('T')
+T = TypeVar('T', covariant=True)
 
 class object:
     def __init__(self): pass
diff --git a/test-data/unit/parse-python312.test b/test-data/unit/parse-python312.test
index 90ee96f38deb..2b1f9b42e0f7 100644
--- a/test-data/unit/parse-python312.test
+++ b/test-data/unit/parse-python312.test
@@ -1,5 +1,5 @@
 [case testPEP695TypeAlias]
-# mypy: enable-incomplete-feature=NewGenericSyntax
+# comment
 type A[T] = C[T]
 [out]
 MypyFile:1(
@@ -15,7 +15,7 @@ MypyFile:1(
             NameExpr(T)))))))
 
 [case testPEP695GenericFunction]
-# mypy: enable-incomplete-feature=NewGenericSyntax
+# comment
 
 def f[T](): pass
 def g[T: str](): pass
@@ -46,7 +46,7 @@ MypyFile:1(
       PassStmt:5())))
 
 [case testPEP695ParamSpec]
-# mypy: enable-incomplete-feature=NewGenericSyntax
+# comment
 
 def f[**P](): pass
 class C[T: int, **P]: pass
@@ -68,7 +68,7 @@ MypyFile:1(
     PassStmt:4()))
 
 [case testPEP695TypeVarTuple]
-# mypy: enable-incomplete-feature=NewGenericSyntax
+# comment
 
 def f[*Ts](): pass
 class C[T: int, *Ts]: pass
diff --git a/test-data/unit/pythoneval.test b/test-data/unit/pythoneval.test
index dbf228623d7c..89f01bff963e 100644
--- a/test-data/unit/pythoneval.test
+++ b/test-data/unit/pythoneval.test
@@ -2099,7 +2099,7 @@ def f(d: Description) -> None:
 _testDataclassStrictOptionalAlwaysSet.py:9: note: Revealed type is "def (Union[builtins.int, None]) -> Union[builtins.str, None]"
 
 [case testPEP695VarianceInference]
-# flags: --python-version=3.12 --enable-incomplete-feature=NewGenericSyntax
+# flags: --python-version=3.12
 from typing import Callable, Final
 
 class Job[_R_co]:
@@ -2120,7 +2120,7 @@ def func(
 _testPEP695VarianceInference.py:17: error: Incompatible types in assignment (expression has type "Job[None]", variable has type "Job[int]")
 
 [case testPEP695TypeAliasWithDifferentTargetTypes]
-# flags: --python-version=3.12 --enable-incomplete-feature=NewGenericSyntax
+# flags: --python-version=3.12
 from typing import Any, Callable, List, Literal, TypedDict, overload, TypeAlias, TypeVar, Never
 
 class C[T]: pass
@@ -2196,3 +2196,23 @@ type K4 = None | B[int]
 
 type L1 = Never
 type L2 = list[Never]
+
+[case testPEP695VarianceInferenceSpecialCaseWithTypeshed]
+# flags: --python-version=3.12
+class C1[T1, T2](list[T1]):
+    def m(self, a: T2) -> None: ...
+
+def func1(p: C1[int, object]):
+    x: C1[int, int] = p
+
+class C2[T1, T2, T3](dict[T2, T3]):
+    def m(self, a: T1) -> None: ...
+
+def func2(p: C2[object, int, int]):
+    x: C2[int, int, int] = p
+
+class C3[T1, T2](tuple[T1, ...]):
+    def m(self, a: T2) -> None: ...
+
+def func3(p: C3[int, object]):
+    x: C3[int, int] = p
diff --git a/test-data/unit/reports.test b/test-data/unit/reports.test
index 81e24240af2d..6e0fdba8aaa3 100644
--- a/test-data/unit/reports.test
+++ b/test-data/unit/reports.test
@@ -27,7 +27,7 @@ def bar() -> str:
 def untyped_function():
   return 42
 [outfile build/cobertura.xml]
-<coverage timestamp="$TIMESTAMP" version="$VERSION" line-rate="0.7500" branch-rate="0">
+<coverage timestamp="$TIMESTAMP" version="$VERSION" line-rate="0.7500" branch-rate="0" lines-covered="6" lines-valid="8">
   <sources>
     <source>$PWD</source>
   </sources>
@@ -81,7 +81,7 @@ def foo(a: int) -> MyDict:
     return {"a": a}
 md: MyDict = MyDict(**foo(42))
 [outfile build/cobertura.xml]
-<coverage timestamp="$TIMESTAMP" version="$VERSION" line-rate="1.0000" branch-rate="0">
+<coverage timestamp="$TIMESTAMP" version="$VERSION" line-rate="1.0000" branch-rate="0" lines-covered="6" lines-valid="6">
   <sources>
     <source>$PWD</source>
   </sources>
diff --git a/test-data/unit/stubgen.test b/test-data/unit/stubgen.test
index fe0538159aa3..69781e9d2143 100644
--- a/test-data/unit/stubgen.test
+++ b/test-data/unit/stubgen.test
@@ -1640,11 +1640,11 @@ def all():
 from _typeshed import Incomplete
 from collections.abc import Generator
 
-def f() -> Generator[Incomplete, None, None]: ...
-def g() -> Generator[None, Incomplete, None]: ...
-def h1() -> Generator[None, None, None]: ...
+def f() -> Generator[Incomplete]: ...
+def g() -> Generator[None, Incomplete]: ...
+def h1() -> Generator[None]: ...
 def h2() -> Generator[None, None, Incomplete]: ...
-def h3() -> Generator[None, None, None]: ...
+def h3() -> Generator[None]: ...
 def all() -> Generator[Incomplete, Incomplete, Incomplete]: ...
 
 [case testFunctionYieldsNone]
@@ -1656,8 +1656,8 @@ def g():
 [out]
 from collections.abc import Generator
 
-def f() -> Generator[None, None, None]: ...
-def g() -> Generator[None, None, None]: ...
+def f() -> Generator[None]: ...
+def g() -> Generator[None]: ...
 
 [case testGeneratorAlreadyDefined]
 class Generator:
@@ -1671,7 +1671,7 @@ from collections.abc import Generator as _Generator
 
 class Generator: ...
 
-def f() -> _Generator[Incomplete, None, None]: ...
+def f() -> _Generator[Incomplete]: ...
 
 [case testGeneratorYieldFrom]
 def g1():
@@ -1692,10 +1692,10 @@ def g5():
 from _typeshed import Incomplete
 from collections.abc import Generator
 
-def g1() -> Generator[Incomplete, Incomplete, None]: ...
-def g2() -> Generator[Incomplete, Incomplete, None]: ...
-def g3() -> Generator[Incomplete, Incomplete, None]: ...
-def g4() -> Generator[Incomplete, Incomplete, None]: ...
+def g1() -> Generator[Incomplete, Incomplete]: ...
+def g2() -> Generator[Incomplete, Incomplete]: ...
+def g3() -> Generator[Incomplete, Incomplete]: ...
+def g4() -> Generator[Incomplete, Incomplete]: ...
 def g5() -> Generator[Incomplete, Incomplete, Incomplete]: ...
 
 [case testGeneratorYieldAndYieldFrom]
@@ -1728,13 +1728,13 @@ def g7():
 from _typeshed import Incomplete
 from collections.abc import Generator
 
-def g1() -> Generator[Incomplete, Incomplete, None]: ...
-def g2() -> Generator[Incomplete, Incomplete, None]: ...
-def g3() -> Generator[Incomplete, Incomplete, None]: ...
-def g4() -> Generator[Incomplete, Incomplete, None]: ...
-def g5() -> Generator[Incomplete, Incomplete, None]: ...
+def g1() -> Generator[Incomplete, Incomplete]: ...
+def g2() -> Generator[Incomplete, Incomplete]: ...
+def g3() -> Generator[Incomplete, Incomplete]: ...
+def g4() -> Generator[Incomplete, Incomplete]: ...
+def g5() -> Generator[Incomplete, Incomplete]: ...
 def g6() -> Generator[Incomplete, Incomplete, Incomplete]: ...
-def g7() -> Generator[Incomplete, Incomplete, None]: ...
+def g7() -> Generator[Incomplete, Incomplete]: ...
 
 [case testCallable]
 from typing import Callable