GitHub Actions Workflow Template for Monorepo (matrix)

A complete, caching-enabled GitHub Actions workflow for Monorepo (matrix). Drop it in .github/workflows/ci.yml and adjust.

This template builds and tests a Monorepo (matrix) project with dependency caching and sensible defaults. It runs a matrix across packages so only what changed is built (wire your own change detection).

The workflow

name: CI
on: [push, pull_request]
jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        package: [api, web, worker]
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with: { node-version: 20, cache: npm }
      - run: npm ci
      - run: npm test --workspace ${{ matrix.package }}

What it does

• Runs a job per package in parallel
• Pattern for affected-only builds

Run it cheaper

Change runs-on: ubuntu-latest to a Latchkey label to run this same workflow at roughly 69% lower per-minute cost, with self-healing for transient failures.

Related guides