diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..bd8e743
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,42 @@
+name: ci
+
+# Continuous integration: run the unit test suite on every push to main and
+# every pull request, so each commit carries a trustworthy pass/fail mark.
+# Network-dependent integration tests are deselected (-m "not integration")
+# to keep this signal stable — upstream rate-limiting or transient network
+# errors must never turn a correct commit red. Run those locally with a
+# bare `python -m pytest` when you need to exercise the live pipeline.
+#
+# Cross-platform coverage is handled by release.yml, which builds and smoke
+# tests the PyInstaller binary on windows/ubuntu/macos per release tag.
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    name: Run unit tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+          cache: pip
+          cache-dependency-path: pyproject.toml
+
+      - name: Install package and test deps
+        run: |
+          python -m pip install --upgrade pip
+          pip install -e .
+          pip install pytest pytest-asyncio
+
+      - name: Run unit tests (skip network integration tests)
+        run: python -m pytest -m "not integration"
diff --git a/agent-web-search.spec b/agent-web-search.spec
index 32e0d0d..6bd99ad 100644
--- a/agent-web-search.spec
+++ b/agent-web-search.spec
@@ -7,7 +7,7 @@
 # Build: pyinstaller agent-web-search.spec --noconfirm
 # Verified working: ddgs search returns results through the bundled exe.
 
-from PyInstaller.utils.hooks import collect_submodules
+from PyInstaller.utils.hooks import collect_submodules, copy_metadata
 
 block_cipher = None
 
@@ -35,6 +35,11 @@ hiddenimports += [
     "sse_starlette",
 ]
 
+# Bundle our own dist-info so importlib.metadata.version() resolves at runtime.
+# __init__.py reads __version__ from package metadata; without this the frozen
+# binary would hit PackageNotFoundError and silently fall back to "0.0.0+dev".
+datas = copy_metadata("agent-web-search")
+
 # Excluded — only things known-safe to drop. (mcp.cli sys.exits on import;
 # the rest are unused heavy stdlib. Do NOT exclude xml/email — pkg_resources
 # and plistlib depend on them.)
@@ -48,7 +53,7 @@ a = Analysis(
     ["src/agent_web_search/__main__.py"],
     pathex=["src"],
     binaries=[],
-    datas=[],
+    datas=datas,
     hiddenimports=hiddenimports,
     hookspath=[],
     runtime_hooks=[],
diff --git a/pyproject.toml b/pyproject.toml
index f94603e..aa6713c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "agent-web-search"
-version = "0.1.0"
+version = "0.2.1"
 description = "A free, unlimited, stable web-search MCP tool for coding agents"
 readme = "README.md"
 license = { text = "MIT" }
@@ -32,3 +32,6 @@ dev = [
 [tool.pytest.ini_options]
 asyncio_mode = "auto"
 testpaths = ["tests"]
+markers = [
+    "integration: tests that hit the real network (skipped in CI by default; run locally with a bare `python -m pytest`)",
+]
diff --git a/scripts/smoke_test.py b/scripts/smoke_test.py
index 0b0b287..f8afdc9 100644
--- a/scripts/smoke_test.py
+++ b/scripts/smoke_test.py
@@ -62,12 +62,28 @@ def main() -> int:
             return 1
 
         resp = json.loads(line)
-        name = resp.get("result", {}).get("serverInfo", {}).get("name", "")
+        server_info = resp.get("result", {}).get("serverInfo", {})
+        name = server_info.get("name", "")
         if "agent-web-search" not in name:
             print(f"FAIL: bad server name: {name}", file=sys.stderr)
             return 1
 
-        print(f"smoke test OK: {time.monotonic() - t0:.2f}s startup, server={name}")
+        # Assert the version propagated. __init__.py reads it from package
+        # metadata via importlib.metadata; the spec bundles that metadata via
+        # copy_metadata(). If either link breaks, the binary silently falls
+        # back to "0.0.0+dev" — catch that here so a broken release never
+        # ships with a garbage version.
+        version = server_info.get("version", "")
+        if not version or version.startswith("0.0.0+dev"):
+            print(
+                f"FAIL: bad/missing server version: {version!r} "
+                "(expected a real release version — the binary likely fell back "
+                "to the dev placeholder, meaning package metadata isn't bundled)",
+                file=sys.stderr,
+            )
+            return 1
+
+        print(f"smoke test OK: {time.monotonic() - t0:.2f}s startup, server={name} v{version}")
         return 0
     finally:
         proc.terminate()
diff --git a/src/agent_web_search/__init__.py b/src/agent_web_search/__init__.py
index 53aabd2..7fca0d3 100644
--- a/src/agent_web_search/__init__.py
+++ b/src/agent_web_search/__init__.py
@@ -1,3 +1,15 @@
 """agent-web-search: a free, unlimited, stable web-search MCP tool."""
 
-__version__ = "0.1.0"
+from importlib.metadata import PackageNotFoundError, version
+
+try:
+    # Single source of truth: pyproject.toml's [project] version. Reading it
+    # via importlib.metadata means changing pyproject.toml is the only edit
+    # needed at release — __version__, the MCP serverInfo.version, and the
+    # PyInstaller-built binary all follow automatically once installed.
+    __version__ = version("agent-web-search")
+except PackageNotFoundError:
+    # Not installed (e.g. running from a source checkout without `pip install
+    # -e .`). Fall back rather than crash — tests and dev workflows that don't
+    # care about the version still work.
+    __version__ = "0.0.0+dev"
diff --git a/tests/test_mcp_stdio.py b/tests/test_mcp_stdio.py
index 19b6d93..d53855d 100644
--- a/tests/test_mcp_stdio.py
+++ b/tests/test_mcp_stdio.py
@@ -127,7 +127,9 @@ def test_stdout_is_clean_json_rpc_only(server_env: dict[str, str]) -> None:
         import time
 
         time.sleep(0.3)
-        proc.stdin and proc.stdin.close()
+        # communicate() closes stdin itself; closing it manually first makes
+        # communicate()'s internal stdin.flush() raise "flush of closed file"
+        # on Linux (Windows tolerates it). Don't pre-close.
         out, _ = proc.communicate(timeout=5)
     except subprocess.TimeoutExpired:
         proc.kill()
@@ -142,6 +144,7 @@ def test_stdout_is_clean_json_rpc_only(server_env: dict[str, str]) -> None:
     assert parsed >= 2, f"expected >=2 JSON-RPC responses, got {parsed}"
 
 
+@pytest.mark.integration
 def test_tools_call_returns_json_shaped_response(
     server_env: dict[str, str]
 ) -> None:
@@ -150,6 +153,11 @@ def test_tools_call_returns_json_shaped_response(
     We only assert the server returns a well-formed JSON-RPC response whose
     content is valid JSON (a results list or an error object), tolerant of
     live rate-limiting. Live results aren't guaranteed.
+
+    Marked ``integration`` because it hits the live ddgs/DuckDuckGo pipeline
+    and is therefore weather-dependent. CI deselects it (``-m "not
+    integration"``); run it locally with a bare ``python -m pytest`` to
+    exercise the real network path.
     """
     proc = _spawn(server_env)
     try: