github

name	github
version	1.1.0
updated	"2026-02-01T00:00:00.000Z"
description	GitHub CLI (gh) and GitHub Actions workflow development. This skill should be used when working with gh commands (PRs, issues, releases, API), writing GitHub Actions workflows, configuring workflow triggers/jobs/steps, optimizing CI/CD pipelines with caching/parallelization, reducing action minutes, matrix builds, self-hosted runners, debugging workflow failures, setting up Node.js/npm/pnpm/yarn with actions/setup-node, or caching Playwright/Cypress browsers.

GitHub

Overview

Comprehensive GitHub development covering the gh CLI for repository operations and GitHub Actions for CI/CD automation, with emphasis on workflow optimization and cost reduction.

gh CLI Quick Reference

Authentication and common operations:

# Auth
gh auth login                    # Interactive login
gh auth status                   # Check auth state
gh auth token                    # Print token

# PRs
gh pr create --fill              # Create PR, auto-fill title/body from commits
gh pr create --base main --head feature --title "Title" --body "Body"
gh pr list --state open          # List open PRs
gh pr view 123                   # View PR details
gh pr checkout 123               # Checkout PR branch
gh pr merge 123 --squash         # Squash merge

# Issues
gh issue create --title "Bug" --body "Description" --label bug
gh issue list --assignee @me     # My assigned issues
gh issue close 123 --reason completed

# Releases
gh release create v1.0.0 --generate-notes
gh release upload v1.0.0 ./dist/*

# API (powerful for automation)
gh api repos/{owner}/{repo}/actions/runs --jq '.workflow_runs[].status'
gh api graphql -f query='{ viewer { login } }'

See gh-cli.md for complete command reference.

GitHub Actions Workflow Structure

name: CI
on:
  push:
    branches: [main]
    paths-ignore: ['**.md']      # Skip docs-only changes
  pull_request:
    branches: [main]
  workflow_dispatch:              # Manual trigger

concurrency:                      # Cancel in-flight runs
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:
  build:
    runs-on: ubuntu-latest        # or: self-hosted, macos-latest, windows-latest
    timeout-minutes: 10           # Prevent runaway jobs
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'            # Built-in caching
      - run: npm ci
      - run: npm test

See actions-triggers-jobs.md and actions-steps-expressions.md for triggers, contexts, expressions, and job configuration.

Optimization Strategies

1. Caching (Biggest Impact)

# Dependency caching - use setup-action's built-in cache
- uses: actions/setup-node@v4
  with:
    cache: 'npm'                  # Also: yarn, pnpm

# Custom cache for build artifacts
- uses: actions/cache@v4
  with:
    path: |
      ~/.cache
      .build
    key: ${{ runner.os }}-build-${{ hashFiles('**/lockfile') }}
    restore-keys: |
      ${{ runner.os }}-build-

2. Parallelization

# Matrix builds - run variants in parallel
jobs:
  test:
    strategy:
      fail-fast: false            # Don't cancel siblings on failure
      matrix:
        os: [ubuntu-latest, macos-latest]
        node: [18, 20, 22]
    runs-on: ${{ matrix.os }}

# Split large test suites
  test-shard:
    strategy:
      matrix:
        shard: [1, 2, 3, 4]
    steps:
      - run: npm test -- --shard=${{ matrix.shard }}/4

3. Early Termination

# Path filters - skip irrelevant changes
on:
  push:
    paths:
      - 'src/**'
      - 'package.json'
    paths-ignore:
      - '**.md'
      - 'docs/**'

# Conditional jobs
jobs:
  deploy:
    if: github.event_name == 'push' && github.ref == 'refs/heads/main'

# Skip CI commits
    if: "!contains(github.event.head_commit.message, '[skip ci]')"

4. Reduce Minutes

Technique	Savings
Use ubuntu-latest over macos-latest	10x cheaper
Shallow clone: fetch-depth: 1	Faster checkout
Cache dependencies	50-80% faster installs
Parallel matrix jobs	Wall-clock time
timeout-minutes on jobs	Prevent runaways
concurrency.cancel-in-progress	Kill stale runs

See optimization-caching.md and optimization-workflows.md for advanced patterns including Docker layer caching, artifact strategies, and self-hosted runner optimization.

Common Patterns

Reusable Workflows

# .github/workflows/reusable-build.yml
on:
  workflow_call:
    inputs:
      node-version:
        type: string
        default: '20'

# Caller workflow
jobs:
  build:
    uses: ./.github/workflows/reusable-build.yml
    with:
      node-version: '22'

Composite Actions

# .github/actions/setup/action.yml
name: 'Setup'
runs:
  using: composite
  steps:
    - uses: actions/checkout@v4
    - uses: actions/setup-node@v4
      with:
        node-version: '20'
        cache: 'npm'
    - run: npm ci
      shell: bash

Job Dependencies

jobs:
  build:
    # ...
  test:
    needs: build
  deploy:
    needs: [build, test]
    if: success()              # Only if all dependencies passed

Debugging Workflows

# Enable debug logging
env:
  ACTIONS_STEP_DEBUG: true

# Dump contexts
- run: echo '${{ toJSON(github) }}'
- run: echo '${{ toJSON(env) }}'

# SSH into runner (act or tmate)
- uses: mxschmitt/action-tmate@v3
  if: failure()

Local testing with act:

act push                         # Simulate push event
act -j build                     # Run specific job
act --secret-file .secrets       # With secrets

Resources

• gh-cli.md - Complete gh command reference
• actions-triggers-jobs.md - Workflow triggers, concurrency, jobs, matrix, runners, services
• actions-steps-expressions.md - Steps, conditionals, contexts, expressions, secrets, artifacts
• optimization-caching.md - Dependency caching, build cache, Docker layer caching
• optimization-workflows.md - Parallelization, path filters, conditional jobs, checkout optimization
• nodejs.md - Node.js/npm/pnpm/yarn setup, Playwright/Cypress caching, monorepo patterns