feat: add AI-powered changeset workflow for monorepo releases

AGENTS.md

@@ -21,12 +21,16 @@ open-workflows/
 │   ├── doc-sync/              # AI-powered
 │   │   ├── action.yml
 │   │   └── skill.md
+│   ├── changeset/             # AI-powered
+│   │   ├── action.yml
+│   │   └── skill.md
 │   └── release/               # No AI - pure script
 │       ├── action.yml
 │       └── src/publish.ts
 ├── scripts/                    # OpenCode custom tools (copied to ~/.config/opencode/tool/)
 │   ├── submit-review.ts       # PR review tool
-│   └── apply-labels.ts        # Issue labeling tool
+│   ├── apply-labels.ts        # Issue labeling tool
+│   └── write-changeset.ts     # Changeset file writer
 ├── src/
 │   └── cli/                   # Workflow installer CLI
 │       ├── index.ts
@@ -43,6 +47,7 @@ open-workflows/
 | `pr-review` | Yes | AI code review, posts sticky comment |
 | `issue-label` | Yes | Auto-labels based on content |
 | `doc-sync` | Yes | Syncs docs with code changes |
+| `changeset` | Yes | AI-generated changesets for monorepo releases |
 | `release` | No | Semantic versioning + npm publish with provenance |
 
 ## WHERE TO LOOK
@@ -64,6 +69,7 @@ Tools in `scripts/` are copied to `~/.config/opencode/tool/` at runtime.
 |--------|---------|
 | `submit-review.ts` | Post/update sticky PR comment |
 | `apply-labels.ts` | Create + apply labels |
+| `write-changeset.ts` | Write changeset files to `.changeset/` |
 
 ## RELEASE SCRIPT
 

README.md

@@ -17,6 +17,7 @@ The CLI will prompt you to select workflows and install them to `.github/workflo
 | `pr-review` | Yes | AI-powered code reviews |
 | `issue-label` | Yes | Auto-label issues based on content |
 | `doc-sync` | Yes | Keep docs in sync with code changes |
+| `changeset` | Yes | AI-generated changesets for monorepo releases |
 | `release` | No | Semantic versioning with npm provenance |
 
 ## Manual Usage
@@ -72,6 +73,38 @@ jobs:
 
 No NPM_TOKEN needed - uses OIDC trusted publishing with provenance.
 
+### Changeset Action (AI-Powered)
+
+```yaml
+name: AI Changeset
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+jobs:
+  changeset:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          ref: ${{ github.head_ref }}
+          token: ${{ secrets.GITHUB_TOKEN }}
+      - uses: activadee/open-workflows/actions/changeset@main
+        with:
+          mode: commit  # or 'comment' to suggest via PR comment
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
+```
+
+The changeset action analyzes PR changes and generates [Changesets](https://github.com/changesets/changesets) files automatically:
+- Detects which packages are affected in monorepos
+- Infers version bump type from conventional commits
+- Writes user-facing changelog entries
+
 ## Authentication
 
 ### For AI Actions
@@ -107,12 +140,18 @@ OPTIONS
 
 ## How It Works
 
-**AI Actions (pr-review, issue-label, doc-sync):**
+**AI Actions (pr-review, issue-label, doc-sync, changeset):**
 1. Workflow triggers on GitHub event
 2. Composite action sets up Bun and OpenCode
 3. OpenCode runs with the bundled skill
 4. AI analyzes content and takes action
 
+**Changeset Action:**
+1. Triggers on PR open/update
+2. AI analyzes diff, commits, and PR description
+3. Generates `.changeset/<random>.md` with package bumps and changelog
+4. Either commits to PR branch or suggests via comment
+
 **Release Action:**
 1. Manually triggered with version bump type
 2. Generates changelog from git commits

actions/changeset/action.yml

@@ -0,0 +1,46 @@
+name: 'AI Changeset'
+description: 'AI-powered changeset generation for monorepo releases'
+author: 'activadee'
+
+inputs:
+  model:
+    description: 'Model to use for changeset generation'
+    required: false
+    default: 'anthropic/claude-sonnet-4-5'
+  mode:
+    description: 'Operation mode: commit (auto-commit changeset) or comment (suggest via PR comment)'
+    required: false
+    default: 'commit'
+
+runs:
+  using: 'composite'
+  steps:
+    - name: Setup Bun
+      uses: oven-sh/setup-bun@v2
+
+    - name: Setup OpenCode auth
+      if: env.OPENCODE_AUTH != ''
+      shell: bash
+      run: |
+        mkdir -p ~/.local/share/opencode
+        echo "$OPENCODE_AUTH" > ~/.local/share/opencode/auth.json
+    - name: Install opencode-ai
+      shell: bash
+      run: |
+        curl -fsSL https://opencode.ai/install | bash
+    - name: Install skill and tools
+      shell: bash
+      run: |
+        mkdir -p .opencode/skill/changeset
+        cp "${{ github.action_path }}/skill.md" .opencode/skill/changeset/SKILL.md
+        mkdir -p ~/.config/opencode/tool
+        cp "${{ github.action_path }}/../../scripts/"*.ts ~/.config/opencode/tool/
+        cd ~/.config/opencode && bun add @opencode-ai/plugin
+
+    - name: Generate Changeset
+      shell: bash
+      run: |
+        opencode run --model "${{ inputs.model }}" \
+          "Load the changeset skill. Generate changeset for PR ${{ github.event.pull_request.number }} in mode: ${{ inputs.mode }}"
+      env:
+        GITHUB_TOKEN: ${{ github.token }}