ucsandman/claude-code-capability-primer/claude-code-github-actions

Claude Code GitHub Actions

What It Is

Claude Code GitHub Actions (anthropics/claude-code-action@v1) runs Claude inside GitHub Actions. Triggered by @claude mentions in PR/issue comments or automatically on repository events. Responds with code changes, reviews, implementations. Executes server-side on GitHub runners (not locally).

Distinct from: GitHub MCP server (raw API access); local Claude Code CLI (interactive terminal); GitHub Code Review (automatic PR reviews without triggers).

Setup

Quick install: Run /install-github-app in Claude Code terminal. Guides you through:

• Installing the official Anthropic GitHub App at https://github.com/apps/claude
• Adding ANTHROPIC_API_KEY to repository secrets
• Creating .github/workflows/claude.yml

Requirements: Repository admin access. GitHub App requests read & write permissions for Contents, Issues, and Pull Requests.

Manual setup (if quickstart fails or for cloud providers):

1. Install app at https://github.com/apps/claude
2. Add ANTHROPIC_API_KEY secret to repository
3. Copy workflow YAML from https://github.com/anthropics/claude-code-action/blob/main/examples/claude.yml into .github/workflows/

Workflow Structure

Tag-based (responds to mentions):

on:
  issue_comment:
    types: [created]
  pull_request_review_comment:
    types: [created]
jobs:
  claude:
    runs-on: ubuntu-latest
    steps:
      - uses: anthropics/claude-code-action@v1
        with:
          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
          # Omit prompt → Claude waits for @claude mention

Automation (runs on event):

on:
  pull_request:
    types: [opened, synchronize]
jobs:
  review:
    runs-on: ubuntu-latest
    steps:
      - uses: anthropics/claude-code-action@v1
        with:
          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
          prompt: "/code-review:code-review"
          # Has prompt → Claude runs immediately

Key Parameters

Prompt optional — omit for tag-based mode (responds to `@claude` mentions). **Required for Claude API; not needed for Bedrock/Vertex (use cloud auth instead).*

When to Use It

✅ Route to GitHub Actions for:

• Recurring PR reviews on every push/PR
• Auto-implement issues as PRs
• On-demand fixes via @claude comments
• Team workflows (you don't own local session)
• Scheduled automation (cron, event-triggered)

❌ Use local Claude Code instead for:

• Interactive, exploratory work (tight feedback loops)
• Real-time debugging
• Tasks needing manual approval mid-stream

Trigger Modes

Tag-based (default): Omit prompt. Claude responds only to @claude mentions. Automation: Add prompt. Claude runs immediately on event without waiting for mention. Skills: Use /skill-name or /plugin-name:skill-name in prompt. For repo skills, include actions/checkout@v4 before the action step.

Common Examples

PR review on every change:

on:
  pull_request:
    types: [opened, synchronize]
prompt: "/code-review:code-review"

Issue → PR implementation:

on:
  issues:
    types: [opened]
prompt: "Implement this feature. Create a PR with all changes."

Scheduled report:

on:
  schedule:
    - cron: "0 9 * * *"
prompt: "Summarize yesterday's commits and open issues"

In-comment triggers (tag-based):

@claude implement this feature
@claude review for security
@claude fix the TypeError

Project Guidance

Claude respects CLAUDE.md at repo root (coding style, review criteria, project rules). Place it there; action reads automatically.

Upgrading from Beta

Breaking changes in v1.0:

Amazon Bedrock & Google Vertex AI

For enterprise environments, route through your own cloud infrastructure (data residency, billing control).

Setup requires:

1. Create custom GitHub App (or use Anthropic's official app)
2. Configure cloud provider authentication (OIDC for security — no static keys)
3. Add secrets to repository
4. Create workflow with cloud auth steps + use_bedrock: "true" or use_vertex: "true"

Bedrock: Request Claude model access in Bedrock; configure GitHub OIDC → AWS IAM role with AmazonBedrockFullAccess; set AWS_ROLE_TO_ASSUME secret; use region-prefixed model IDs (e.g., us.anthropic.claude-sonnet-4-6).

Vertex AI: Enable Vertex AI + IAM APIs; configure Workload Identity Federation for GitHub; create service account with Vertex AI User role; set GCP_WORKLOAD_IDENTITY_PROVIDER and GCP_SERVICE_ACCOUNT secrets; action auto-retrieves project ID from auth.

See official GitHub Action repo for complete cloud setup guides.

Costs & Limits

GitHub Actions minutes: Each run consumes org quota. See GitHub billing.

API tokens: Each Claude interaction charges tokens (varies by complexity/codebase size). Set --max-turns cap to control iterations.

Optimize:

• Use specific @claude commands to reduce unnecessary runs
• Set claude_args: "--max-turns 5" to cap iterations
• Use workflow concurrency limits to prevent parallel runs
• Schedule at off-peak times

Troubleshooting

Model IDs

Defaults to Sonnet. Override with claude_args: "--model <id>":

• Claude Opus 4.8: claude-opus-4-8
• Claude Sonnet 4.6: claude-sonnet-4-6
• Claude Haiku 4.5: claude-haiku-4-5-20251001
• Bedrock (region-prefixed): us.anthropic.claude-opus-4-8

Next Steps

1. Run /install-github-app in Claude Code
2. Test with @claude help in a PR comment
3. Add CLAUDE.md to repo root to guide Claude's decisions
4. See https://github.com/anthropics/claude-code-action/tree/main/examples for complete workflows