build: auto-update SKILL.md based on release diffs

.github/scripts/update_skill.py

@@ -0,0 +1,116 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import json
+import urllib.request
+import sys
+
+def get_gemini_response(api_key, prompt):
+    url = f"https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent?key={api_key}"
+    headers = {'Content-Type': 'application/json'}
+    data = {
+        "contents": [{
+            "parts": [{"text": prompt}]
+        }]
+    }
+
+    req = urllib.request.Request(url, data=json.dumps(data).encode('utf-8'), headers=headers)
+    try:
+        with urllib.request.urlopen(req) as response:
+            res_data = json.loads(response.read().decode('utf-8'))
+            return res_data['candidates'][0]['content']['parts'][0]['text']
+    except urllib.error.HTTPError as e:
+        print(f"Gemini API Error ({e.code}): {e.reason}", file=sys.stderr)
+        try:
+            error_body = e.read().decode('utf-8')
+            print(f"Error details: {error_body}", file=sys.stderr)
+        except:
+            pass
+        return None
+    except Exception as e:
+        print(f"Error calling Gemini API: {e}", file=sys.stderr)
+        return None
+
+def main():
+    api_key = os.getenv("GEMINI_API_KEY")
+    diff_file = os.getenv("DIFF_FILE", "release_diff.patch")
+    skill_file = os.getenv("SKILL_FILE", ".gemini/skills/android-maps-compose/SKILL.md")
+
+    if not api_key:
+        print("GEMINI_API_KEY not found", file=sys.stderr)
+        sys.exit(1)
+
+    if not os.path.exists(diff_file):
+        print(f"Diff file {diff_file} not found.", file=sys.stderr)
+        sys.exit(1)
+
+    if not os.path.exists(skill_file):
+        print(f"Skill file {skill_file} not found.", file=sys.stderr)
+        sys.exit(1)
+
+    with open(diff_file, "r") as f:
+        diff_content = f.read()
+
+    with open(skill_file, "r") as f:
+        skill_content = f.read()
+
+    prompt = f"""
+You are an expert technical writer and Android developer. 
+Your task is to update the Gemini CLI skill instructions for an SDK based on the latest release changes.
+
+Here is the current `SKILL.md` file:
+```markdown
+{skill_content}
+```
+
+Here is the git diff representing the changes introduced in this release:
+```diff
+{diff_content}
+```
+
+Please analyze the diff to identify any new APIs, deprecated functions, structural changes, or changes in implementation best practices.
+Update the `SKILL.md` content to incorporate these new concepts or deprecations.
+
+CRITICAL REQUIREMENTS:
+- Preserve the overall markdown structure and formatting of the existing `SKILL.md`.
+- Ensure you keep the YAML frontmatter intact at the top of the file (between `---`).
+- Do NOT remove the `// x-release-please-version` comments in the Gradle dependencies, as they are required by our release process.
+- Return ONLY the raw updated markdown content. Do NOT wrap it in ```markdown...``` code blocks, just return the exact file content so it can be directly saved.
+"""
+
+    print("Requesting update from Gemini...", file=sys.stderr)
+    response_text = get_gemini_response(api_key, prompt)
+    if response_text:
+        # Clean up response text if the model wrapped it in markdown code blocks despite instructions
+        if response_text.startswith("```markdown"):
+            response_text = response_text.replace("```markdown\n", "", 1)
+            if response_text.endswith("```"):
+                response_text = response_text[:-3]
+        elif response_text.startswith("```"):
+            response_text = response_text.replace("```\n", "", 1)
+            if response_text.endswith("```"):
+                response_text = response_text[:-3]
+
+        # Trim whitespace at the very beginning or end
+        response_text = response_text.strip() + "\n"
+
+        with open(skill_file, "w") as f:
+            f.write(response_text)
+        print(f"Successfully updated {skill_file}", file=sys.stderr)
+    else:
+        sys.exit(1)
+
+if __name__ == "__main__":
+    main()

.github/workflows/update-skill.yml

@@ -0,0 +1,66 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Update Skill
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  update-skill:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0 # Fetch all history for tags and diffs
+          token: ${{ secrets.SYNCED_GITHUB_TOKEN_REPO }}
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Generate Diff
+        run: |
+          # The new release tag is GITHUB_REF_NAME when triggered on release
+          # Find the tag immediately preceding this one
+          PREVIOUS_TAG=$(git describe --tags --abbrev=0 ${GITHUB_REF_NAME}^ 2>/dev/null || echo "")
+
+          if [ -z "$PREVIOUS_TAG" ]; then
+            # If no previous tag, diff against the initial commit
+            INITIAL_COMMIT=$(git rev-list --max-parents=0 HEAD)
+            git diff $INITIAL_COMMIT..HEAD > release_diff.patch
+          else
+            git diff $PREVIOUS_TAG..$GITHUB_REF_NAME > release_diff.patch
+          fi
+
+      - name: Update Skill via Gemini
+        env:
+          GEMINI_API_KEY: ${{ secrets.GEMINI_API_KEY }}
+        run: python .github/scripts/update_skill.py
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v7
+        with:
+          token: ${{ secrets.SYNCED_GITHUB_TOKEN_REPO }}
+          commit-message: "docs: update SKILL.md based on release ${{ github.ref_name }}"
+          title: "docs: update SKILL.md for release ${{ github.ref_name }}"
+          body: "Automatically generated PR to update `SKILL.md` for the latest release `${{ github.ref_name }}`."
+          branch: "update-skill-for-${{ github.ref_name }}"
+          base: main
+          labels: |
+            docs
+            automerge