feat(changelog): Add changelog preview action and CLI command

.github/workflows/changelog-preview.yml

@@ -0,0 +1,105 @@
+name: Changelog Preview
+
+on:
+  # Allow this workflow to be called from other repositories
+  workflow_call:
+    inputs:
+      craft-version:
+        description: 'Version of Craft to use (tag or "latest")'
+        required: false
+        type: string
+        default: 'latest'
+
+  # Also run on PRs in this repository (for dogfooding)
+  # Includes 'edited' and 'labeled' to update when PR title/description/labels change
+  pull_request:
+    types: [opened, synchronize, reopened, edited, labeled]
+
+permissions:
+  pull-requests: write
+
+jobs:
+  preview:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      # Install Craft using the shared install action
+      # TODO: Change to @v2 or @master after this PR is merged
+      - name: Install Craft
+        uses: getsentry/craft/install@pull/669/head
+        with:
+          craft-version: ${{ inputs.craft-version || 'latest' }}
+
+      - name: Generate Changelog Preview
+        shell: bash
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          CRAFT_LOG_LEVEL: Warn
+        run: |
+          PR_NUMBER="${{ github.event.pull_request.number }}"
+
+          # Generate changelog with current PR injected and highlighted (JSON format)
+          echo "Running craft changelog --pr $PR_NUMBER --format json..."
+          RESULT=$(craft changelog --pr "$PR_NUMBER" --format json 2>/dev/null || echo '{"changelog":"","bumpType":null}')
+
+          # Extract fields from JSON
+          CHANGELOG=$(echo "$RESULT" | jq -r '.changelog // ""')
+          BUMP_TYPE=$(echo "$RESULT" | jq -r '.bumpType // "none"')
+
+          if [[ -z "$CHANGELOG" ]]; then
+            CHANGELOG="_No changelog entries will be generated from this PR._"
+          fi
+
+          # Format bump type for display
+          case "$BUMP_TYPE" in
+            major) BUMP_BADGE="🔴 **Major** (breaking changes)" ;;
+            minor) BUMP_BADGE="🟡 **Minor** (new features)" ;;
+            patch) BUMP_BADGE="🟢 **Patch** (bug fixes)" ;;
+            *) BUMP_BADGE="⚪ **None** (no version bump detected)" ;;
+          esac
+
+          # Build comment body using a temp file (safer than heredoc)
+          COMMENT_FILE=$(mktemp)
+          cat > "$COMMENT_FILE" << CRAFT_CHANGELOG_COMMENT_END
+          <!-- craft-changelog-preview -->
+          ## Suggested Version Bump
+
+          ${BUMP_BADGE}
+
+          ## 📋 Changelog Preview
+
+          This is how your changes will appear in the changelog.
+          Entries from this PR are highlighted with a left border (blockquote style).
+
+          ---
+
+          ${CHANGELOG}
+
+          ---
+
+          <sub>🤖 This preview updates automatically when you update the PR.</sub>
+          CRAFT_CHANGELOG_COMMENT_END
+
+          # Find existing comment with our marker
+          COMMENT_ID=$(gh api \
+            "repos/$GITHUB_REPOSITORY/issues/$PR_NUMBER/comments" \
+            --jq '.[] | select(.body | contains("<!-- craft-changelog-preview -->")) | .id' \
+            | head -1)
+
+          if [[ -n "$COMMENT_ID" ]]; then
+            echo "Updating existing comment $COMMENT_ID..."
+            gh api -X PATCH \
+              "repos/$GITHUB_REPOSITORY/issues/comments/$COMMENT_ID" \
+              -F body=@"$COMMENT_FILE"
+          else
+            echo "Creating new comment..."
+            gh api -X POST \
+              "repos/$GITHUB_REPOSITORY/issues/$PR_NUMBER/comments" \
+              -F body=@"$COMMENT_FILE"
+          fi
+
+          rm -f "$COMMENT_FILE"

README.md

@@ -43,6 +43,7 @@ craft publish 1.2.3
 - **Changelog Management** - Auto-generate changelogs from commits or validate manual entries
 - **Workspace Support** - Handle monorepos with NPM/Yarn workspaces
 - **CI Integration** - Wait for CI to pass, download artifacts, and publish
+- **GitHub Actions** - Built-in actions for release preparation and changelog previews
 
 ## Configuration
 
@@ -83,6 +84,78 @@ See the [configuration reference](https://getsentry.github.io/craft/configuratio
 
 See the [targets documentation](https://getsentry.github.io/craft/targets/) for configuration details.
 
+## GitHub Actions
+
+Craft provides GitHub Actions for automating releases and previewing changelog entries.
+
+### Prepare Release Action
+
+Automates the `craft prepare` workflow in GitHub Actions:
+
+```yaml
+name: Release
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'Version to release (or "auto")'
+        required: false
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - uses: getsentry/craft@v2
+        with:
+          version: ${{ github.event.inputs.version }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+```
+
+**Inputs:**
+
+| Input | Description | Default |
+|-------|-------------|---------|
+| `version` | Version to release (semver, "auto", "major", "minor", "patch") | Uses `versioning.policy` from config |
+| `merge_target` | Target branch to merge into | Default branch |
+| `force` | Force release even with blockers | `false` |
+| `blocker_label` | Label that blocks releases | `release-blocker` |
+| `publish_repo` | Repository for publish issues | `{owner}/publish` |
+
+**Outputs:**
+
+| Output | Description |
+|--------|-------------|
+| `version` | The resolved version being released |
+| `branch` | The release branch name |
+| `sha` | The commit SHA on the release branch |
+| `changelog` | The changelog for this release |
+
+### Changelog Preview (Reusable Workflow)
+
+Posts a preview comment on PRs showing how they'll appear in the changelog:
+
+```yaml
+name: Changelog Preview
+on:
+  pull_request:
+    types: [opened, synchronize, reopened, edited, labeled]
+
+jobs:
+  changelog-preview:
+    uses: getsentry/craft/.github/workflows/changelog-preview.yml@v2
+    secrets: inherit
+```
+
+The workflow will:
+- Generate the upcoming changelog including the PR's changes
+- Highlight entries from the PR using blockquote style (left border)
+- Post a comment on the PR with the preview
+- Automatically update when you update the PR (push, edit title/description, or change labels)
+
 ## Contributing
 
 See [CONTRIBUTING.md](CONTRIBUTING.md) for development setup and guidelines.

action.yml

@@ -83,42 +83,8 @@ runs:
         echo "GIT_AUTHOR_NAME=${GIT_USER_NAME}" >> $GITHUB_ENV
         echo "EMAIL=${GIT_USER_EMAIL}" >> $GITHUB_ENV
 
-    - name: Download Craft from build artifact
-      id: artifact
-      if: github.repository == 'getsentry/craft'
-      uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4
-      continue-on-error: true
-      with:
-        name: ${{ github.sha }}
-        path: /tmp/craft-artifact
-
-    - name: Install Craft from artifact
-      if: steps.artifact.outcome == 'success'
-      shell: bash
-      run: |
-        echo "Installing Craft from build artifact..."
-        sudo install -m 755 /tmp/craft-artifact/dist/craft /usr/local/bin/craft
-
-    - name: Install Craft from release
-      if: steps.artifact.outcome != 'success'
-      shell: bash
-      run: |
-        # Try action ref first (e.g., v2, 2.15.0)
-        ACTION_REF="${{ github.action_ref }}"
-        CRAFT_URL="https://github.com/getsentry/craft/releases/download/${ACTION_REF}/craft"
-
-        echo "Trying to download Craft from: ${CRAFT_URL}"
-
-        # Fallback to latest if ref doesn't have a release
-        if ! curl -sfI "$CRAFT_URL" >/dev/null 2>&1; then
-          echo "Release not found for ref '${ACTION_REF}', falling back to latest..."
-          CRAFT_URL=$(curl -s "https://github.com/ghapi/repos/getsentry/craft/releases/latest" \
-            | jq -r '.assets[] | select(.name == "craft") | .browser_download_url')
-        fi
-
-        echo "Installing Craft from: ${CRAFT_URL}"
-        sudo curl -sL -o /usr/local/bin/craft "$CRAFT_URL"
-        sudo chmod +x /usr/local/bin/craft
+    - name: Install Craft
+      uses: ./install
 
     - name: Craft Prepare
       id: craft

docs/astro.config.mjs

@@ -23,6 +23,7 @@ export default defineConfig({
             { label: 'Introduction', slug: '' },
             { label: 'Installation', slug: 'getting-started' },
             { label: 'Configuration', slug: 'configuration' },
+            { label: 'GitHub Actions', slug: 'github-actions' },
           ],
         },
         {