Add automated release workflow

.github/workflows/ci.yml

@@ -29,7 +29,7 @@ jobs:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
           set -euo pipefail
-          gh aw compile drafter review fix queue-triage ci-triage --approve
+          gh aw compile drafter review fix release queue-triage ci-triage --approve
 
       - name: Check for lock drift
         run: |

.github/workflows/install-labels.yml

@@ -34,6 +34,7 @@ jobs:
               { name: 'agent/fix-working', description: 'The fix agent is actively working on this PR', color: 'FBCA04' },
               { name: 'agent/workflow-edits-allowed', description: 'Pre-authorizes agent runs to edit protected files without the request_review gate', color: '5319E7' },
               { name: 'agent/flake-tracker', description: 'Marks the CI flake tracker issue the merge queue analyzer maintains', color: '1D76DB' },
+              { name: 'release', description: 'Release PR created by the release agent', color: '0075CA' },
             ];
 
             const { owner, repo } = context.repo;

.github/workflows/publish-release.yml

@@ -0,0 +1,39 @@
+name: Publish Release
+on:
+  pull_request:
+    types: [closed]
+
+# When a release PR is merged, create the corresponding GitHub release
+# with the release notes from the PR body.
+jobs:
+  publish:
+    if: |
+      github.event.pull_request.merged == true &&
+      contains(github.event.pull_request.labels.*.name, 'release') &&
+      startsWith(github.event.pull_request.head.ref, 'release/')
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: write
+    steps:
+      - name: Extract version from branch name
+        id: version
+        env:
+          HEAD_REF: ${{ github.event.pull_request.head.ref }}
+        run: |
+          version="${HEAD_REF#release/}"
+          echo "version=$version" >> "$GITHUB_OUTPUT"
+          echo "Publishing release: $version"
+
+      - name: Create GitHub Release
+        env:
+          GH_TOKEN: ${{ github.token }}
+          VERSION: ${{ steps.version.outputs.version }}
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+          REPO: ${{ github.repository }}
+        run: |
+          pr_body=$(gh pr view "$PR_NUMBER" --repo "$REPO" --json body --jq .body)
+
+          gh release create "$VERSION" \
+            --repo "$REPO" \
+            --title "Release $VERSION" \
+            --notes "$pr_body"

.github/workflows/release.md

@@ -0,0 +1,89 @@
+---
+description: |
+  Automated release agent for this repository. Runs weekly to create a
+  release PR with release notes from git history since the last release.
+  The PR requires human review and approval before merge. When merged,
+  a separate workflow creates the GitHub release with the tag.
+
+on:
+  schedule: weekly on monday
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  issues: read
+  pull-requests: read
+
+model: claude-sonnet-4-5-20250929
+engine:
+  id: claude
+tools:
+  bash: ["*"]
+  github:
+    toolsets: [default]
+
+safe-outputs:
+  github-app:
+    client-id: ${{ vars.GH_AW_APP_CLIENT_ID }}
+    private-key: ${{ secrets.GH_AW_APP_PRIVATE_KEY }}
+  create-pull-request:
+    max: 1
+    branch-prefix: release/
+    allowed-files:
+      - RELEASE-NOTES.md
+  noop:
+  missing-data:
+---
+
+# Release Agent
+
+This workflow runs weekly to create a release PR.
+
+## Your task
+
+1. **Check for existing release PRs**: Before doing anything else, run
+   `gh pr list --label release --state open --json number --jq length`
+   to check if a release PR is already open. If the count is non-zero,
+   use `noop` to report that a release PR is already open.
+
+2. **Fetch full history**: The checkout is shallow by default. Run
+   `git fetch --unshallow --tags` so that all tags and commit history
+   are available.
+
+3. **Determine the next version**: Run `scripts/next-version.sh` to get
+   the next version string (e.g., `v0.3.0`).
+
+4. **Generate release notes**: Use GitHub's release notes generation API
+   as a starting point:
+   ```bash
+   gh api repos/$GITHUB_REPOSITORY/releases/generate-notes \
+     -f tag_name="<next-version>" \
+     -f previous_tag_name="<last-tag>" \
+     --jq .body
+   ```
+   Then refine the output: group changes by category (Features, Bug Fixes,
+   Documentation, Dependencies, Other), add a brief summary at the top,
+   and highlight any breaking changes.
+
+5. **Write RELEASE-NOTES.md**: Write the final release notes to
+   `RELEASE-NOTES.md` at the repository root. This file is overwritten
+   each release.
+
+6. **Create the release PR**: Use the `create-pull-request` safe-output
+   with:
+   - **Title**: `Release <version>` (e.g., "Release v0.3.0")
+   - **Branch**: `<version>` (e.g., "v0.3.0") — the `release/` prefix
+     is added automatically by the branch-prefix setting
+   - **Body**: The release notes from RELEASE-NOTES.md
+   - **Labels**: `release`
+
+7. **Handle edge cases**:
+   - If there are no changes since the last release, use `noop`
+   - If you cannot determine the version or history, use `missing-data`
+
+## Constraints
+
+- Never push directly to the default branch
+- Only modify RELEASE-NOTES.md — do not touch other files
+- Always include "Generated-by: AI" in the PR body
+- Require human review for all releases

aw.yml

@@ -8,6 +8,7 @@ includes:
   - .github/workflows/drafter.md
   - .github/workflows/review.md
   - .github/workflows/fix.md
+  - .github/workflows/release.md
   - .github/workflows/merge.yml
   - .github/workflows/install-labels.yml
   - .github/workflows/upgrade.yml

justfile

@@ -21,7 +21,7 @@ setup:
 
 # Compile all gh-aw workflow .md sources to .lock.yml (run `just setup` first).
 compile:
-    gh aw compile drafter review fix queue-triage ci-triage --approve
+    gh aw compile drafter review fix release queue-triage ci-triage --approve
 
 # Setup + compile in one step.
 all: setup compile

scripts/install-labels.js

@@ -58,6 +58,11 @@ const LABELS = [
     description: 'Marks the CI flake tracker issue the merge queue analyzer maintains',
     color: '1D76DB', // blue
   },
+  {
+    name: 'release',
+    description: 'Release PR created by the release agent',
+    color: '0075CA', // blue
+  },
 ];
 
 /**

scripts/next-version.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+# Determine the next release version by reading git tags.
+# This project uses v0.x.0 minor releases.
+set -euo pipefail
+
+latest=$(git tag --list 'v*' --sort=-v:refname | head -1)
+
+if [ -z "$latest" ]; then
+    echo "v0.1.0"
+    exit 0
+fi
+
+# Strip leading 'v', split on '.', bump minor, reset patch
+IFS='.' read -r major minor _patch <<< "${latest#v}"
+echo "v${major}.$((minor + 1)).0"