diff --git a/.github/workflows/generation_check.yaml b/.github/workflows/generation_check.yaml
new file mode 100644
index 000000000000..4e8c12451f2f
--- /dev/null
+++ b/.github/workflows/generation_check.yaml
@@ -0,0 +1,75 @@
+---
+name: generation-check
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+  # Allows manual triggering for debugging purpose.
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read # Read repository contents
+
+jobs:
+  regeneration:
+    name: Regenerate and verify clean git tree
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read # Read repository contents
+      issues: write # Required for creating issue on main branch failure
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+      - uses: dorny/paths-filter@fbd0ab8f3e69293af611ebaee6363fc25e6d187d # v4.0.1
+        id: changes
+        with:
+          filters: |
+            librarian:
+              - 'librarian.yaml'
+      # Version of librarian is pulled from librarian.yaml,
+      # action is pinned to commit SHA to satisfy blanket security policy.
+      - uses: googleapis/librarian@35997441eafc2b02716804f9baba1e3f04f8a44f # v0.31.1
+        if: steps.changes.outputs.librarian == 'true' || github.event_name == 'workflow_dispatch' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
+      - name: Use Node.js 22
+        if: steps.changes.outputs.librarian == 'true' || github.event_name == 'workflow_dispatch' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
+        uses: actions/setup-node@249970729cb0ef3589644e2896645e5dc5ba9c38 # v6.5.0
+        with:
+          node-version: 22
+      - name: Setup pnpm
+        if: steps.changes.outputs.librarian == 'true' || github.event_name == 'workflow_dispatch' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
+        uses: pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1 # v4
+        with:
+          version: ^7.0.0
+      - name: Install tools
+        if: steps.changes.outputs.librarian == 'true' || github.event_name == 'workflow_dispatch' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
+        run: librarian install
+      - name: Regenerate
+        if: steps.changes.outputs.librarian == 'true' || github.event_name == 'workflow_dispatch' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
+        run: |
+          librarian generate --all
+          if [ -n "$(git status --porcelain)" ]; then
+            git status
+            echo "==================== GIT DIFF ===================="
+            git diff
+            echo "=================================================="
+            echo "Regeneration failed. Please run 'librarian generate --all' to update the generated files."
+            exit 1
+          fi
+      - name: Create issue if previous step fails
+        if: ${{ failure() && github.ref == 'refs/heads/main' }}
+        uses: googleapis/librarian/.github/actions/create-issue-on-failure@35997441eafc2b02716804f9baba1e3f04f8a44f # v0.31.1
+        with:
+          title: "Librarian generate diff check failed on main branch"
+          body: |
+            The librarian generate diff check failed on main branch.
+
+            To keep the `main` branch healthy, please consider **reverting the triggering change** first. Once the revert is merged, you can investigate the failure and submit a new PR with the fix.
+
+            Please check the logs: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
diff --git a/.github/workflows/librarian_tidy.yml b/.github/workflows/librarian_tidy.yml
new file mode 100644
index 000000000000..e830d1d3f187
--- /dev/null
+++ b/.github/workflows/librarian_tidy.yml
@@ -0,0 +1,47 @@
+name: librarian tidy
+
+on:
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  tidy-check:
+    name: Verify librarian.yaml is tidy
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+      - uses: dorny/paths-filter@fbd0ab8f3e69293af611ebaee6363fc25e6d187d # v4.0.1
+        id: changes
+        with:
+          filters: |
+            librarian:
+              - 'librarian.yaml'
+      # Version of librarian is pulled from librarian.yaml,
+      # action is pinned to commit SHA to satisfy blanket security policy.
+      - uses: googleapis/librarian@35997441eafc2b02716804f9baba1e3f04f8a44f # v0.31.1
+
+      - name: Run librarian tidy
+        if: steps.changes.outputs.librarian == 'true'
+        run: librarian tidy
+
+      - name: Check for diff
+        if: steps.changes.outputs.librarian == 'true'
+        run: |
+          if ! git diff --exit-code; then
+            V=$(librarian config get version 2>/dev/null || echo "latest")
+            echo "librarian.yaml is not tidy. Please run:"
+            echo ""
+            echo "  librarian tidy"
+            echo ""
+            echo "to tidy librarian.yaml and commit the changes."
+            exit 1
+          fi
diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 1986fffc0f38..48aef931009f 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -2,15 +2,15 @@
   "core/common": "8.0.0",
   "core/dev-packages/jsdoc-fresh": "6.0.0",
   "core/dev-packages/jsdoc-region-tag": "5.0.0",
-  "core/dev-packages/pack-n-play": "5.0.0",
+  "core/dev-packages/pack-n-play": "5.0.1",
   "core/generator/gapic-generator-typescript": "5.0.0",
   "core/packages/gapic-node-processing": "0.2.0",
   "core/packages/gax": "6.0.0",
   "core/packages/gaxios": "7.3.0",
-  "core/packages/gcp-metadata": "9.0.0",
+  "core/packages/gcp-metadata": "9.0.1",
   "core/packages/google-auth-library-nodejs": "11.0.0",
   "core/packages/logging-utils": "2.0.0",
-  "core/packages/nodejs-googleapis-common": "9.0.0",
+  "core/packages/nodejs-googleapis-common": "9.0.1",
   "core/packages/nodejs-proto-files": "6.0.0",
   "core/packages/proto3-json-serializer-nodejs": "4.0.0",
   "core/packages/retry-request": "9.0.0",
@@ -21,9 +21,9 @@
   "core/precise-date": "6.0.0",
   "core/projectify": "6.0.0",
   "core/promisify": "6.0.0",
-  "handwritten/bigquery": "9.0.0",
+  "handwritten/bigquery": "9.0.1",
   "handwritten/bigquery-storage": "6.0.0",
-  "handwritten/bigtable": "7.0.0",
+  "handwritten/bigtable": "7.1.0",
   "handwritten/cloud-profiler": "8.0.0",
   "handwritten/datastore": "11.0.0",
   "handwritten/error-reporting": "4.0.0",
@@ -104,7 +104,7 @@
   "packages/google-cloud-connectors": "0.6.0",
   "packages/google-cloud-contactcenterinsights": "5.0.0",
   "packages/google-cloud-contentwarehouse": "3.0.0",
-  "packages/google-cloud-databasecenter": "0.4.0",
+  "packages/google-cloud-databasecenter": "0.4.1",
   "packages/google-cloud-datacatalog": "6.0.0",
   "packages/google-cloud-datacatalog-lineage": "3.0.0",
   "packages/google-cloud-datacatalog-lineage-configmanagement": "0.2.0",
diff --git a/changelog.json b/changelog.json
index f4dc6b25538c..a9e0bf8919e6 100644
--- a/changelog.json
+++ b/changelog.json
@@ -1,6 +1,113 @@
 {
   "repository": "googleapis/google-cloud-node",
   "entries": [
+    {
+      "changes": [
+        {
+          "type": "fix",
+          "sha": "23aee114a947a29f31977aab8de9c1c7ecd62188",
+          "message": "Upgrade types sinon for databasecenter",
+          "issues": [
+            "9098"
+          ]
+        }
+      ],
+      "version": "0.4.1",
+      "language": "JAVASCRIPT",
+      "artifactName": "@google-cloud/databasecenter",
+      "id": "c0b55b44-2b73-457b-9e25-8d86ece8b512",
+      "createTime": "2026-08-05T21:09:31.314Z"
+    },
+    {
+      "changes": [
+        {
+          "type": "feat",
+          "sha": "f63f914e69106f581448837f5ee212ab71f85775",
+          "message": "Split gapic and proto usage from the handwritten library into bigtable-api",
+          "issues": [
+            "8934"
+          ],
+          "scope": "bigtable"
+        }
+      ],
+      "version": "7.1.0",
+      "language": "JAVASCRIPT",
+      "artifactName": "@google-cloud/bigtable",
+      "id": "dc784ab8-295a-4e02-8261-f7935abb2788",
+      "createTime": "2026-08-05T21:09:31.294Z"
+    },
+    {
+      "changes": [
+        {
+          "type": "fix",
+          "sha": "7f8e23c9652e34869c2fafe54f63cc63ac9acaa8",
+          "message": "Remove owlbot configs",
+          "issues": [
+            "8936"
+          ],
+          "scope": "bigquery"
+        }
+      ],
+      "version": "9.0.1",
+      "language": "JAVASCRIPT",
+      "artifactName": "@google-cloud/bigquery",
+      "id": "de1dae99-d138-451f-a0db-e716e0003958",
+      "createTime": "2026-08-05T21:09:31.273Z"
+    },
+    {
+      "changes": [
+        {
+          "type": "fix",
+          "sha": "340364f8fab67adaf4e684fb3241de499394bf6b",
+          "message": "Discovery url handling, error code review helper, and pack-n-play test timeouts",
+          "issues": [
+            "9061"
+          ],
+          "scope": "core"
+        }
+      ],
+      "version": "9.0.1",
+      "language": "JAVASCRIPT",
+      "artifactName": "googleapis-common",
+      "id": "2d37b8dd-1417-4f37-ae57-18b166ea395a",
+      "createTime": "2026-08-05T21:09:31.248Z"
+    },
+    {
+      "changes": [
+        {
+          "type": "fix",
+          "sha": "340364f8fab67adaf4e684fb3241de499394bf6b",
+          "message": "Discovery url handling, error code review helper, and pack-n-play test timeouts",
+          "issues": [
+            "9061"
+          ],
+          "scope": "core"
+        }
+      ],
+      "version": "9.0.1",
+      "language": "JAVASCRIPT",
+      "artifactName": "gcp-metadata",
+      "id": "9eda0e2d-73dd-410e-a223-df0621e697d6",
+      "createTime": "2026-08-05T21:09:31.228Z"
+    },
+    {
+      "changes": [
+        {
+          "type": "fix",
+          "sha": "340364f8fab67adaf4e684fb3241de499394bf6b",
+          "message": "Discovery url handling, error code review helper, and pack-n-play test timeouts",
+          "issues": [
+            "9061"
+          ],
+          "scope": "core"
+        }
+      ],
+      "version": "5.0.1",
+      "language": "JAVASCRIPT",
+      "artifactName": "pack-n-play",
+      "id": "80b6e996-31bf-482f-8d5c-02220564552f",
+      "createTime": "2026-08-05T21:09:31.200Z"
+    },
     {
       "changes": [
         {
@@ -88682,5 +88789,5 @@
       "createTime": "2023-01-28T04:18:24.718Z"
     }
   ],
-  "updateTime": "2026-08-04T23:49:33.509Z"
+  "updateTime": "2026-08-05T21:09:31.314Z"
 }
\ No newline at end of file
diff --git a/core/dev-packages/pack-n-play/CHANGELOG.md b/core/dev-packages/pack-n-play/CHANGELOG.md
index cbfa24ef4098..ff9c3f04cd3c 100644
--- a/core/dev-packages/pack-n-play/CHANGELOG.md
+++ b/core/dev-packages/pack-n-play/CHANGELOG.md
@@ -1,6 +1,13 @@
 # Changelog
 
 
+## [5.0.1](https://github.com/googleapis/google-cloud-node/compare/pack-n-play-v5.0.0...pack-n-play-v5.0.1) (2026-08-05)
+
+
+### Bug Fixes
+
+* **core:** Discovery url handling, error code review helper, and pack-n-play test timeouts ([#9061](https://github.com/googleapis/google-cloud-node/issues/9061)) ([340364f](https://github.com/googleapis/google-cloud-node/commit/340364f8fab67adaf4e684fb3241de499394bf6b))
+
 ## [5.0.0](https://github.com/googleapis/google-cloud-node/compare/pack-n-play-v4.2.3...pack-n-play-v5.0.0) (2026-07-29)
 
 
diff --git a/core/dev-packages/pack-n-play/package.json b/core/dev-packages/pack-n-play/package.json
index ad6dc1a6938b..8c52b49721cd 100644
--- a/core/dev-packages/pack-n-play/package.json
+++ b/core/dev-packages/pack-n-play/package.json
@@ -1,7 +1,7 @@
 {
   "name": "pack-n-play",
   "description": "Ensure your library installs and compiles",
-  "version": "5.0.0",
+  "version": "5.0.1",
   "author": "Google LLC",
   "license": "Apache-2.0",
   "repository": {
diff --git a/core/packages/gcp-metadata/CHANGELOG.md b/core/packages/gcp-metadata/CHANGELOG.md
index ff0063d2f2a9..4ceb65011936 100644
--- a/core/packages/gcp-metadata/CHANGELOG.md
+++ b/core/packages/gcp-metadata/CHANGELOG.md
@@ -5,6 +5,13 @@
 
 [1]: https://www.npmjs.com/package/gcp-metadata?activeTab=versions
 
+## [9.0.1](https://github.com/googleapis/google-cloud-node/compare/gcp-metadata-v9.0.0...gcp-metadata-v9.0.1) (2026-08-05)
+
+
+### Bug Fixes
+
+* **core:** Discovery url handling, error code review helper, and pack-n-play test timeouts ([#9061](https://github.com/googleapis/google-cloud-node/issues/9061)) ([340364f](https://github.com/googleapis/google-cloud-node/commit/340364f8fab67adaf4e684fb3241de499394bf6b))
+
 ## [9.0.0](https://github.com/googleapis/google-cloud-node/compare/gcp-metadata-v8.1.4...gcp-metadata-v9.0.0) (2026-07-29)
 
 
diff --git a/core/packages/gcp-metadata/package.json b/core/packages/gcp-metadata/package.json
index 8b26fc8f3ae1..78eb4d77cc95 100644
--- a/core/packages/gcp-metadata/package.json
+++ b/core/packages/gcp-metadata/package.json
@@ -1,6 +1,6 @@
 {
   "name": "gcp-metadata",
-  "version": "9.0.0",
+  "version": "9.0.1",
   "description": "Get the metadata from a Google Cloud Platform environment",
   "repository": {
     "type": "git",
diff --git a/core/packages/gcp-metadata/samples/package.json b/core/packages/gcp-metadata/samples/package.json
index 5790a1b71927..a7a0992b436f 100644
--- a/core/packages/gcp-metadata/samples/package.json
+++ b/core/packages/gcp-metadata/samples/package.json
@@ -14,7 +14,7 @@
     "test": "mocha"
   },
   "dependencies": {
-    "gcp-metadata": "^9.0.0"
+    "gcp-metadata": "^9.0.1"
   },
   "devDependencies": {
     "chai": "^4.2.0",
diff --git a/core/packages/nodejs-googleapis-common/CHANGELOG.md b/core/packages/nodejs-googleapis-common/CHANGELOG.md
index 511e86585498..cf43f81713c0 100644
--- a/core/packages/nodejs-googleapis-common/CHANGELOG.md
+++ b/core/packages/nodejs-googleapis-common/CHANGELOG.md
@@ -5,6 +5,13 @@
 
 [1]: https://www.npmjs.com/package/nodejs-googleapis-common?activeTab=versions
 
+## [9.0.1](https://github.com/googleapis/google-cloud-node/compare/googleapis-common-v9.0.0...googleapis-common-v9.0.1) (2026-08-05)
+
+
+### Bug Fixes
+
+* **core:** Discovery url handling, error code review helper, and pack-n-play test timeouts ([#9061](https://github.com/googleapis/google-cloud-node/issues/9061)) ([340364f](https://github.com/googleapis/google-cloud-node/commit/340364f8fab67adaf4e684fb3241de499394bf6b))
+
 ## [9.0.0](https://github.com/googleapis/google-cloud-node/compare/googleapis-common-v8.0.3...googleapis-common-v9.0.0) (2026-07-29)
 
 
diff --git a/core/packages/nodejs-googleapis-common/package.json b/core/packages/nodejs-googleapis-common/package.json
index 082b61bf7942..2ad882e902af 100644
--- a/core/packages/nodejs-googleapis-common/package.json
+++ b/core/packages/nodejs-googleapis-common/package.json
@@ -1,6 +1,6 @@
 {
   "name": "googleapis-common",
-  "version": "9.0.0",
+  "version": "9.0.1",
   "description": "A common tooling library used by the googleapis npm module. You probably don't want to use this directly.",
   "repository": {
     "type": "git",
diff --git a/core/packages/nodejs-googleapis-common/samples/package.json b/core/packages/nodejs-googleapis-common/samples/package.json
index 192850261c50..07446f01ac9f 100644
--- a/core/packages/nodejs-googleapis-common/samples/package.json
+++ b/core/packages/nodejs-googleapis-common/samples/package.json
@@ -15,7 +15,7 @@
     "test": "echo \"There are no sample tests 👻\""
   },
   "dependencies": {
-    "googleapis-common": "^9.0.0"
+    "googleapis-common": "^9.0.1"
   },
   "devDependencies": {
     "mocha": "^8.0.0"
diff --git a/handwritten/bigquery/CHANGELOG.md b/handwritten/bigquery/CHANGELOG.md
index af977317129a..12b796fd7bec 100644
--- a/handwritten/bigquery/CHANGELOG.md
+++ b/handwritten/bigquery/CHANGELOG.md
@@ -5,6 +5,13 @@
 
 [1]: https://www.npmjs.com/package/@google-cloud/bigquery?activeTab=versions
 
+## [9.0.1](https://github.com/googleapis/google-cloud-node/compare/bigquery-v9.0.0...bigquery-v9.0.1) (2026-08-05)
+
+
+### Bug Fixes
+
+* **bigquery:** Remove owlbot configs ([#8936](https://github.com/googleapis/google-cloud-node/issues/8936)) ([7f8e23c](https://github.com/googleapis/google-cloud-node/commit/7f8e23c9652e34869c2fafe54f63cc63ac9acaa8))
+
 ## [9.0.0](https://github.com/googleapis/google-cloud-node/compare/bigquery-v8.3.1...bigquery-v9.0.0) (2026-08-04)
 
 
diff --git a/handwritten/bigquery/package.json b/handwritten/bigquery/package.json
index b0d97aa060c1..8c08afd9d8d2 100644
--- a/handwritten/bigquery/package.json
+++ b/handwritten/bigquery/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@google-cloud/bigquery",
   "description": "Google BigQuery Client Library for Node.js",
-  "version": "9.0.0",
+  "version": "9.0.1",
   "license": "Apache-2.0",
   "author": "Google LLC",
   "engines": {
diff --git a/handwritten/bigtable/CHANGELOG.md b/handwritten/bigtable/CHANGELOG.md
index 2acbd3b45145..003c12d67c79 100644
--- a/handwritten/bigtable/CHANGELOG.md
+++ b/handwritten/bigtable/CHANGELOG.md
@@ -5,6 +5,13 @@
 
 [1]: https://www.npmjs.com/package/@google-cloud/bigtable?activeTab=versions
 
+## [7.1.0](https://github.com/googleapis/google-cloud-node/compare/bigtable-v7.0.0...bigtable-v7.1.0) (2026-08-05)
+
+
+### Features
+
+* **bigtable:** Split gapic and proto usage from the handwritten library into bigtable-api ([#8934](https://github.com/googleapis/google-cloud-node/issues/8934)) ([f63f914](https://github.com/googleapis/google-cloud-node/commit/f63f914e69106f581448837f5ee212ab71f85775))
+
 ## [7.0.0](https://github.com/googleapis/google-cloud-node/compare/bigtable-v6.5.1...bigtable-v7.0.0) (2026-08-04)
 
 
diff --git a/handwritten/bigtable/package.json b/handwritten/bigtable/package.json
index 85d6d08be38e..7c5baeebd273 100644
--- a/handwritten/bigtable/package.json
+++ b/handwritten/bigtable/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@google-cloud/bigtable",
-  "version": "7.0.0",
+  "version": "7.1.0",
   "description": "Cloud Bigtable Client Library for Node.js",
   "keywords": [
     "bigtable",
diff --git a/handwritten/storage/package.json b/handwritten/storage/package.json
index ed2c26993026..7f71363f4105 100644
--- a/handwritten/storage/package.json
+++ b/handwritten/storage/package.json
@@ -54,6 +54,7 @@
     "compile:cjs": "tsc -p ./tsconfig.cjs.json",
     "compile:esm": "tsc -p .",
     "compile": "npm run compile:cjs && npm run compile:esm",
+    "compile:sourcemaps": "npm run compile:cjs -- --sourceMap && npm run compile:esm -- --sourceMap",
     "conformance-test": "mocha --parallel build/cjs/conformance-test/ --require build/cjs/conformance-test/globalHooks.js",
     "docs": "jsdoc -c .jsdoc.json",
     "fix": "gts fix",
@@ -61,13 +62,13 @@
     "postcompile": "cp ./src/package-json-helper.cjs ./build/cjs/src && cp ./src/package-json-helper.cjs ./build/esm/src",
     "postcompile:cjs": "babel --plugins gapic-tools/build/src/replaceImportMetaUrl,gapic-tools/build/src/toggleESMFlagVariable build/cjs/src/util.js -o build/cjs/src/util.js && cp internal-tooling/helpers/package.cjs.json build/cjs/package.json",
     "precompile": "rm -rf build/",
-    "preconformance-test": "npm run compile:cjs -- --sourceMap",
-    "predocs": "npm run compile:cjs -- --sourceMap",
+    "preconformance-test": "npm run compile:sourcemaps",
+    "predocs": "npm run compile:sourcemaps",
     "prelint": "cd samples; npm link ../; npm install",
     "prepare": "npm run compile",
     "presystem-test:esm": "npm run compile:esm",
-    "presystem-test": "npm run compile -- --sourceMap",
-    "pretest": "npm run compile -- --sourceMap",
+    "presystem-test": "npm run compile:sourcemaps",
+    "pretest": "npm run compile:sourcemaps",
     "samples-test": "npm link && cd samples/ && npm link ../ && npm test && cd ../",
     "system-test:esm": "mkdir -p $HOME/.config && mocha build/esm/system-test --timeout 600000 --exit",
     "system-test": "mkdir -p $HOME/.config && mocha build/cjs/system-test --timeout 600000 --exit",
diff --git a/handwritten/storage/src/nodejs-common/service.ts b/handwritten/storage/src/nodejs-common/service.ts
index 9173a38f73d7..5a54ebf6ff86 100644
--- a/handwritten/storage/src/nodejs-common/service.ts
+++ b/handwritten/storage/src/nodejs-common/service.ts
@@ -269,13 +269,28 @@ export class Service {
     if (this.providedUserAgent) {
       userAgent = `${this.providedUserAgent} ${userAgent}`;
     }
+    const headers = reqOpts.headers || {};
+    const userTokenKey = Object.keys(headers).find(
+      key => key.toLowerCase() === 'x-goog-gcs-idempotency-token'
+    );
+    const userTokenValue = userTokenKey ? headers[userTokenKey] : undefined;
+    const hasValidUserToken = typeof userTokenValue === 'string' && userTokenValue !== '';
+    const idempotencyToken = hasValidUserToken
+      ? (userTokenValue as string)
+      : crypto.randomUUID();
     reqOpts.headers = {
-      ...reqOpts.headers,
+      ...headers,
       'User-Agent': userAgent,
       'x-goog-api-client': `${getRuntimeTrackingString()} gccl/${
         pkg.version
-      }-${getModuleFormat()} gccl-invocation-id/${crypto.randomUUID()}`,
+      }-${getModuleFormat()} gccl-invocation-id/${idempotencyToken}`,
     };
+    if (!hasValidUserToken) {
+      if (userTokenKey) {
+        delete reqOpts.headers[userTokenKey];
+      }
+      reqOpts.headers['x-goog-gcs-idempotency-token'] = idempotencyToken;
+    }
 
     if (reqOpts[GCCL_GCS_CMD_KEY]) {
       reqOpts.headers['x-goog-api-client'] +=
diff --git a/handwritten/storage/src/nodejs-common/util.ts b/handwritten/storage/src/nodejs-common/util.ts
index e6c4db98b095..f0c4c7f419b2 100644
--- a/handwritten/storage/src/nodejs-common/util.ts
+++ b/handwritten/storage/src/nodejs-common/util.ts
@@ -1042,11 +1042,13 @@ export class Util {
   }
 
   _getDefaultHeaders(gcclGcsCmd?: string) {
+    const idempotencyToken = crypto.randomUUID();
     const headers = {
       'User-Agent': getUserAgentString(),
       'x-goog-api-client': `${getRuntimeTrackingString()} gccl/${
         packageJson.version
-      }-${getModuleFormat()} gccl-invocation-id/${crypto.randomUUID()}`,
+      }-${getModuleFormat()} gccl-invocation-id/${idempotencyToken}`,
+      'x-goog-gcs-idempotency-token': idempotencyToken,
     };
 
     if (gcclGcsCmd) {
diff --git a/handwritten/storage/src/resumable-upload.ts b/handwritten/storage/src/resumable-upload.ts
index df63ec637b1d..d1adfee9d153 100644
--- a/handwritten/storage/src/resumable-upload.ts
+++ b/handwritten/storage/src/resumable-upload.ts
@@ -338,7 +338,11 @@ export class Upload extends Writable {
   timeOfFirstRequest: number;
   isPartialUpload: boolean;
 
-  private currentInvocationId = {
+  private currentInvocationId: {
+    checkUploadStatus: string;
+    chunk: string;
+    uri: string;
+  } = {
     checkUploadStatus: crypto.randomUUID(),
     chunk: crypto.randomUUID(),
     uri: crypto.randomUUID(),
@@ -806,6 +810,21 @@ export class Upload extends Writable {
       delete metadata.contentType;
     }
 
+    const userTokenKey = Object.keys(this.customRequestOptions?.headers || {}).find(
+      key => key.toLowerCase() === 'x-goog-gcs-idempotency-token'
+    );
+    const userTokenValue = userTokenKey ? this.customRequestOptions?.headers?.[userTokenKey] : undefined;
+    const hasValidUserToken = typeof userTokenValue === 'string' && userTokenValue !== '';
+    if (hasValidUserToken) {
+      this.currentInvocationId.uri = userTokenValue as string;
+    } else if (userTokenKey && this.customRequestOptions?.headers) {
+      this.customRequestOptions = {
+        ...this.customRequestOptions,
+        headers: { ...this.customRequestOptions.headers },
+      };
+      delete this.customRequestOptions.headers![userTokenKey];
+    }
+
     let googAPIClient = `${getRuntimeTrackingString()} gccl/${
       packageJson.version
     }-${getModuleFormat()} gccl-invocation-id/${this.currentInvocationId.uri}`;
@@ -833,6 +852,10 @@ export class Upload extends Writable {
       },
     };
 
+    if (!hasValidUserToken) {
+      reqOpts.headers!['x-goog-gcs-idempotency-token'] = this.currentInvocationId.uri;
+    }
+
     if (metadata.contentLength) {
       reqOpts.headers!['X-Upload-Content-Length'] =
         metadata.contentLength.toString();
@@ -995,6 +1018,21 @@ export class Upload extends Writable {
       },
     });
 
+    const userTokenKey = Object.keys(this.customRequestOptions?.headers || {}).find(
+      key => key.toLowerCase() === 'x-goog-gcs-idempotency-token'
+    );
+    const userTokenValue = userTokenKey ? this.customRequestOptions?.headers?.[userTokenKey] : undefined;
+    const hasValidUserToken = typeof userTokenValue === 'string' && userTokenValue !== '';
+    if (hasValidUserToken) {
+      this.currentInvocationId.chunk = userTokenValue as string;
+    } else if (userTokenKey && this.customRequestOptions?.headers) {
+      this.customRequestOptions = {
+        ...this.customRequestOptions,
+        headers: { ...this.customRequestOptions.headers },
+      };
+      delete this.customRequestOptions.headers![userTokenKey];
+    }
+
     let googAPIClient = `${getRuntimeTrackingString()} gccl/${
       packageJson.version
     }-${getModuleFormat()} gccl-invocation-id/${
@@ -1010,6 +1048,10 @@ export class Upload extends Writable {
       'x-goog-api-client': googAPIClient,
     };
 
+    if (!hasValidUserToken) {
+      headers['x-goog-gcs-idempotency-token'] = this.currentInvocationId.chunk;
+    }
+
     // If using multiple chunk upload, set appropriate header
     if (multiChunkMode) {
       // We need to know how much data is available upstream to set the `Content-Range` header.
@@ -1209,6 +1251,21 @@ export class Upload extends Writable {
   async checkUploadStatus(
     config: CheckUploadStatusConfig = {},
   ): Promise<GaxiosResponse<FileMetadata | void>> {
+    const userTokenKey = Object.keys(this.customRequestOptions?.headers || {}).find(
+      key => key.toLowerCase() === 'x-goog-gcs-idempotency-token'
+    );
+    const userTokenValue = userTokenKey ? this.customRequestOptions?.headers?.[userTokenKey] : undefined;
+    const hasValidUserToken = typeof userTokenValue === 'string' && userTokenValue !== '';
+    if (hasValidUserToken) {
+      this.currentInvocationId.checkUploadStatus = userTokenValue as string;
+    } else if (userTokenKey && this.customRequestOptions?.headers) {
+      this.customRequestOptions = {
+        ...this.customRequestOptions,
+        headers: { ...this.customRequestOptions.headers },
+      };
+      delete this.customRequestOptions.headers![userTokenKey];
+    }
+
     let googAPIClient = `${getRuntimeTrackingString()} gccl/${
       packageJson.version
     }-${getModuleFormat()} gccl-invocation-id/${
@@ -1230,6 +1287,10 @@ export class Upload extends Writable {
       },
     };
 
+    if (!hasValidUserToken) {
+      opts.headers!['x-goog-gcs-idempotency-token'] = this.currentInvocationId.checkUploadStatus;
+    }
+
     try {
       const resp = await this.makeRequest(opts);
 
diff --git a/handwritten/storage/test/headers.ts b/handwritten/storage/test/headers.ts
index 9ccc685814bb..a19e56556597 100644
--- a/handwritten/storage/test/headers.ts
+++ b/handwritten/storage/test/headers.ts
@@ -65,11 +65,15 @@ describe('headers', () => {
     } catch (err) {
       if (err !== error) throw err;
     }
-    assert.ok(
-      /^gl-node\/(?<nodeVersion>[^W]+) gccl\/(?<gccl>[^W]+) gccl-invocation-id\/(?<gcclInvocationId>[^W]+)$/.test(
-        requests[0].headers['x-goog-api-client']
-      )
-    );
+    const apiClientHeader = requests[0].headers['x-goog-api-client'];
+    const match =
+      /^gl-node\/(?<nodeVersion>[^W]+) gccl\/(?<gccl>[^W]+) gccl-invocation-id\/(?<gcclInvocationId>[^W]+)$/.exec(
+        apiClientHeader
+      );
+    assert.ok(match);
+    const invocationId = match.groups!.gcclInvocationId;
+    const idempotencyToken = requests[0].headers['x-goog-gcs-idempotency-token'];
+    assert.strictEqual(idempotencyToken, invocationId);
   });
 
   it('populates x-goog-api-client header (deno)', async () => {
@@ -87,10 +91,34 @@ describe('headers', () => {
     } catch (err) {
       if (err !== error) throw err;
     }
-    assert.ok(
-      /^gl-deno\/0.00.0 gccl\/(?<gccl>[^W]+) gccl-invocation-id\/(?<gcclInvocationId>[^W]+)$/.test(
-        requests[1].headers['x-goog-api-client']
-      )
-    );
+    const apiClientHeader = requests[1].headers['x-goog-api-client'];
+    const match =
+      /^gl-deno\/0.00.0 gccl\/(?<gccl>[^W]+) gccl-invocation-id\/(?<gcclInvocationId>[^W]+)$/.exec(
+        apiClientHeader
+      );
+    assert.ok(match);
+    const invocationId = match.groups!.gcclInvocationId;
+    const idempotencyToken = requests[1].headers['x-goog-gcs-idempotency-token'];
+    assert.strictEqual(idempotencyToken, invocationId);
+  });
+
+  it('generates unique tokens for different requests', async () => {
+    const storage = new Storage();
+    const bucket = storage.bucket('foo-bucket');
+    try {
+      await bucket.create();
+    } catch (err) {
+      if (err !== error) throw err;
+    }
+    try {
+      await bucket.create();
+    } catch (err) {
+      if (err !== error) throw err;
+    }
+    const token1 = requests[requests.length - 2].headers['x-goog-gcs-idempotency-token'];
+    const token2 = requests[requests.length - 1].headers['x-goog-gcs-idempotency-token'];
+    assert.ok(token1);
+    assert.ok(token2);
+    assert.notStrictEqual(token1, token2);
   });
 });
diff --git a/handwritten/storage/test/nodejs-common/service.ts b/handwritten/storage/test/nodejs-common/service.ts
index 502c4e5419f9..66ebd1cc8f53 100644
--- a/handwritten/storage/test/nodejs-common/service.ts
+++ b/handwritten/storage/test/nodejs-common/service.ts
@@ -487,6 +487,82 @@ describe('Service', () => {
       service.request_(reqOpts, assert.ifError);
     });
 
+    it('should add the x-goog-gcs-idempotency-token header matching the gccl-invocation-id', done => {
+      service.makeAuthenticatedRequest = (reqOpts: DecorateRequestOptions) => {
+        const pkg = service.packageJson;
+        const r = new RegExp(
+          `^gl-node/${process.versions.node} gccl/${
+            pkg.version
+          }-${getModuleFormat()} gccl-invocation-id/(?<gcclInvocationId>[^W]+)$`
+        );
+        const match = r.exec(reqOpts.headers!['x-goog-api-client']);
+        assert.ok(match);
+        const invocationId = match.groups!.gcclInvocationId;
+        const idempotencyToken = reqOpts.headers!['x-goog-gcs-idempotency-token'];
+        assert.strictEqual(idempotencyToken, invocationId);
+        done();
+      };
+
+      service.request_(reqOpts, assert.ifError);
+    });
+
+    it('should respect user-provided x-goog-gcs-idempotency-token case-insensitively and align it with gccl-invocation-id', done => {
+      const customToken = 'my-custom-token-123';
+      const customReqOpts = {
+        ...reqOpts,
+        headers: {
+          'X-Goog-Gcs-Idempotency-Token': customToken,
+        },
+      };
+
+      service.makeAuthenticatedRequest = (reqOpts: DecorateRequestOptions) => {
+        const pkg = service.packageJson;
+        const r = new RegExp(
+          `^gl-node/${process.versions.node} gccl/${
+            pkg.version
+          }-${getModuleFormat()} gccl-invocation-id/(?<gcclInvocationId>[^W]+)$`
+        );
+        const match = r.exec(reqOpts.headers!['x-goog-api-client']);
+        assert.ok(match);
+        const invocationId = match.groups!.gcclInvocationId;
+        assert.strictEqual(invocationId, customToken);
+
+        // Verify there is no duplicate x-goog-gcs-idempotency-token header
+        assert.strictEqual(reqOpts.headers!['x-goog-gcs-idempotency-token'], undefined);
+        assert.strictEqual(reqOpts.headers!['X-Goog-Gcs-Idempotency-Token'], customToken);
+        done();
+      };
+
+      service.request_(customReqOpts, assert.ifError);
+    });
+
+    it('should ignore invalid user-provided idempotency tokens and fallback to generating a UUID', done => {
+      const customReqOpts = {
+        ...reqOpts,
+        headers: {
+          'X-Goog-Gcs-Idempotency-Token': undefined as unknown as string,
+        },
+      };
+
+      service.makeAuthenticatedRequest = (reqOpts: DecorateRequestOptions) => {
+        const pkg = service.packageJson;
+        const r = new RegExp(
+          `^gl-node/${process.versions.node} gccl/${pkg.version
+          }-${getModuleFormat()} gccl-invocation-id/(?<gcclInvocationId>[^W]+)$`
+        );
+        const match = r.exec(reqOpts.headers!['x-goog-api-client']);
+        assert.ok(match);
+        const invocationId = match.groups!.gcclInvocationId;
+
+        // Verify a fallback token was generated and matches the invocation ID
+        const idempotencyToken = reqOpts.headers!['x-goog-gcs-idempotency-token'];
+        assert.strictEqual(idempotencyToken, invocationId);
+        done();
+      };
+
+      service.request_(customReqOpts, assert.ifError);
+    });
+
     it('should add the `gccl-gcs-cmd` to the api-client header when provided', done => {
       const expected = 'example.expected/value';
       service.makeAuthenticatedRequest = (reqOpts: DecorateRequestOptions) => {
diff --git a/handwritten/storage/test/nodejs-common/util.ts b/handwritten/storage/test/nodejs-common/util.ts
index 88e6905ffb52..cf3a9ef47d25 100644
--- a/handwritten/storage/test/nodejs-common/util.ts
+++ b/handwritten/storage/test/nodejs-common/util.ts
@@ -77,10 +77,15 @@ function fakeRequest() {
 }
 
 fakeRequest.defaults = (defaults: r.CoreOptions) => {
-  assert.ok(
-    /^gl-node\/(?<nodeVersion>[^W]+) gccl\/(?<gccl>[^W]+) gccl-invocation-id\/(?<gcclInvocationId>[^W]+)$/.test(
-      defaults.headers!['x-goog-api-client']
-    )
+  const match =
+    /^gl-node\/(?<nodeVersion>[^W]+) gccl\/(?<gccl>[^W]+) gccl-invocation-id\/(?<gcclInvocationId>[^W]+)$/.exec(
+      defaults.headers!['x-goog-api-client'] as string
+    );
+  assert.ok(match);
+  const invocationId = match.groups!.gcclInvocationId;
+  assert.strictEqual(
+    defaults.headers!['x-goog-gcs-idempotency-token'],
+    invocationId
   );
   return fakeRequest;
 };
diff --git a/handwritten/storage/test/resumable-upload.ts b/handwritten/storage/test/resumable-upload.ts
index 6e6985878b00..a5c5c2705ab4 100644
--- a/handwritten/storage/test/resumable-upload.ts
+++ b/handwritten/storage/test/resumable-upload.ts
@@ -877,12 +877,96 @@ describe('resumable-upload', () => {
         delete metadataNoHeaders.contentLength;
         delete metadataNoHeaders.contentType;
         assert.deepStrictEqual(reqOpts.data, metadataNoHeaders);
+        assert(reqOpts.headers);
+        const apiClientHeader = reqOpts.headers['x-goog-api-client'];
+        const match = X_GOOG_API_HEADER_REGEX.exec(apiClientHeader as string);
+        assert.ok(match);
+        const invocationId = match.groups!.gcclInvocationId;
+        const idempotencyToken = reqOpts.headers['x-goog-gcs-idempotency-token'];
+        assert.strictEqual(idempotencyToken, invocationId);
         done();
         return {headers: {location: '/foo'}};
       };
       up.createURI();
     });
 
+    it('should respect user-provided x-goog-gcs-idempotency-token case-insensitively and align it with gccl-invocation-id in createURI', async () => {
+      const customToken = 'my-custom-resumable-token';
+      up.customRequestOptions = {
+        headers: {
+          'X-Goog-Gcs-Idempotency-Token': customToken,
+        },
+      };
+
+      up.authClient.request = async (combinedReqOpts: GaxiosOptions) => {
+        assert(combinedReqOpts.headers);
+        const apiClientHeader = combinedReqOpts.headers['x-goog-api-client'];
+        const match = X_GOOG_API_HEADER_REGEX.exec(apiClientHeader as string);
+        assert.ok(match);
+        const invocationId = match.groups!.gcclInvocationId;
+        assert.strictEqual(invocationId, customToken);
+
+        // Verify there is no duplicate x-goog-gcs-idempotency-token header
+        assert.strictEqual(combinedReqOpts.headers['x-goog-gcs-idempotency-token'], undefined);
+        assert.strictEqual(combinedReqOpts.headers['X-Goog-Gcs-Idempotency-Token'], customToken);
+        return {headers: {location: '/foo'}};
+      };
+
+      await up.createURI();
+    });
+
+    it('should ignore invalid user-provided idempotency tokens and fallback to generating a UUID in createURI', async () => {
+      up.customRequestOptions = {
+        headers: {
+          'X-Goog-Gcs-Idempotency-Token': '', // invalid empty string
+        },
+      };
+
+      up.authClient.request = async (combinedReqOpts: GaxiosOptions) => {
+        assert(combinedReqOpts.headers);
+        const apiClientHeader = combinedReqOpts.headers['x-goog-api-client'];
+        const match = X_GOOG_API_HEADER_REGEX.exec(apiClientHeader as string);
+        assert.ok(match);
+        const invocationId = match.groups!.gcclInvocationId;
+        
+        // Verify a fallback token was generated and matches the invocation ID
+        const idempotencyToken = combinedReqOpts.headers['x-goog-gcs-idempotency-token'];
+        assert.strictEqual(idempotencyToken, invocationId);
+        return {headers: {location: '/foo'}};
+      };
+
+      await up.createURI();
+    });
+
+    it('should reuse the same x-goog-gcs-idempotency-token on retry of createURI', async () => {
+      let invocationCount = 0;
+      let token1 = '';
+      let token2 = '';
+
+      up.makeRequest = async (reqOpts: GaxiosOptions) => {
+        invocationCount++;
+        assert(reqOpts.headers);
+        if (invocationCount === 1) {
+          token1 = reqOpts.headers['x-goog-gcs-idempotency-token'] as string;
+          const error = new GaxiosError(
+            'Retriable error',
+            {} as GaxiosOptions,
+            { status: 500 } as GaxiosResponse
+          );
+          throw error;
+        } else if (invocationCount === 2) {
+          token2 = reqOpts.headers['x-goog-gcs-idempotency-token'] as string;
+          return { headers: { location: '/foo' } };
+        }
+        return { headers: { location: '/foo' } };
+      };
+
+      await up.createURI();
+      assert.strictEqual(invocationCount, 2);
+      assert.ok(token1);
+      assert.strictEqual(token1, token2);
+    });
+
     it('should pass through the KMS key name', done => {
       const kmsKeyName = 'kms-key-name';
       const up = upload({
diff --git a/librarian.yaml b/librarian.yaml
index d4d29c13e820..f55632ab1c08 100644
--- a/librarian.yaml
+++ b/librarian.yaml
@@ -743,7 +743,7 @@ libraries:
     nodejs:
       default_version: v1
   - name: google-cloud-databasecenter
-    version: 0.4.0
+    version: 0.4.1
     apis:
       - path: google/cloud/databasecenter/v1beta
     copyright_year: "2026"
diff --git a/packages/google-cloud-databasecenter/CHANGELOG.md b/packages/google-cloud-databasecenter/CHANGELOG.md
index 1a55e239d67a..366f8547a3bc 100644
--- a/packages/google-cloud-databasecenter/CHANGELOG.md
+++ b/packages/google-cloud-databasecenter/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## [0.4.1](https://github.com/googleapis/google-cloud-node/compare/databasecenter-v0.4.0...databasecenter-v0.4.1) (2026-08-05)
+
+
+### Bug Fixes
+
+* Upgrade types sinon for databasecenter ([#9098](https://github.com/googleapis/google-cloud-node/issues/9098)) ([23aee11](https://github.com/googleapis/google-cloud-node/commit/23aee114a947a29f31977aab8de9c1c7ecd62188))
+
 ## [0.4.0](https://github.com/googleapis/google-cloud-node/compare/databasecenter-v0.3.0...databasecenter-v0.4.0) (2026-08-04)
 
 
diff --git a/packages/google-cloud-databasecenter/package.json b/packages/google-cloud-databasecenter/package.json
index 61bfb2f90cde..fd525383d2c5 100644
--- a/packages/google-cloud-databasecenter/package.json
+++ b/packages/google-cloud-databasecenter/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@google-cloud/databasecenter",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "description": "Database Center API client for Node.js",
   "repository": {
     "type": "git",