name: github:actions description: >- GitHub Actions CI/CD workflow development and run monitoring. Use when creating or editing .github/workflows YAML files, configuring triggers, jobs, matrix strategies, caching, or artifacts. Also covers gh CLI for monitoring runs, viewing logs, and debugging failures. user-invocable: true

GitHub Actions

Workflow Style

Separate jobs with a double blank line. Annotate non-obvious configuration with inline comments. Omit boilerplate that's clear from context.

Example

name: CI

on:
  push:
    branches: [main]
  pull_request:

# Cancel redundant runs on the same branch
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

permissions:
  contents: read

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: oven-sh/setup-bun@v2
      - run: bun install --frozen-lockfile
      - run: bun run lint


  test:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        shard: [1, 2, 3]
    steps:
      - uses: actions/checkout@v4
      - uses: oven-sh/setup-bun@v2
      - run: bun install --frozen-lockfile
      - run: bun test --shard ${{ matrix.shard }}/3


  deploy:
    needs: [lint, test]
    if: github.ref == 'refs/heads/main'
    runs-on: ubuntu-latest
    environment: production  # requires approval in repo settings
    steps:
      - uses: actions/checkout@v4
      - run: ./deploy.sh

Key Patterns

• concurrency at workflow level cancels stale runs on the same branch
• permissions — always set explicitly, least privilege
• fail-fast: false — let all matrix jobs finish so you see all failures
• needs — express job dependencies; jobs without needs run in parallel
• if on jobs — gate deployment on branch, skip expensive work on draft PRs

See references/workflows.md for triggers, caching, artifacts, services, reusable workflows, and outputs.

Monitoring Runs

Quick Reference

gh run list --branch $(git branch --show-current) --limit 5  # check CI
gh run watch <run-id>                                         # wait for completion
gh run view <run-id> --log-failed                             # debug failures

Automated Monitoring

The github:actions-monitor skill automates failure monitoring and log extraction.

See references/cli.md for the full command reference.