How do I install the Github Actions Matrix skill?

Run npx skillmds@latest add loopyluci/github-actions-matrix in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

What does the Github Actions Matrix skill do?

Run test/config combos in parallel with matrix strategy. It is listed under Coding & Dev Tools on SkillMD.

Is Github Actions Matrix safe to use?

This skill has not completed SkillMD's automated safety review yet. Independent scanners report: SkillSpector: PASS, Skill Scanner: PASS. Capability flags: docs only. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Github Actions Matrix?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Github Actions Matrix free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Github Actions Matrix?

LoopyLuci (@loopyluci) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Github Actions Matrix by loopyluci — Agent Skill

Name: Github Actions Matrix
Rating: 4.2 (5 reviews)
Author: LoopyLuci

File contents

GitHub Actions Matrix Builds

Trigger: Use when running tests across multiple OS, language versions, or configurations in parallel.

Basic Matrix

jobs:
  test:
    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest, windows-latest]
        node: [18, 20, 22]
    runs-on: ${{ matrix.os }}
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: ${{ matrix.node }}
      - run: npm test

This creates 3 × 3 = 9 parallel runners.

Controlling the Matrix

Include

include:
  - os: macos
    node: 22         # Extra combo not in main grid
  - os: ubuntu
    node: 18
    coverage: true   # Extra variable

Exclude

exclude:
  - os: windows
    node: 22
  - os: macos
    node: 18

Fail Fast & Concurrency

strategy:
  fail-fast: false      # Continue other jobs even if one fails
  max-parallel: 4       # Max concurrent runners
  matrix: ...

Real-World Examples

Rust — Multiple Checks

strategy:
  matrix:
    job:
      - {cmd: "cargo test", os: ubuntu-latest}
      - {cmd: "cargo clippy", os: ubuntu-latest}
      - {cmd: "cargo fmt --check", os: ubuntu-latest}
      - {cmd: "cargo test", os: macos-latest}
      - {cmd: "cargo test", os: windows-latest}

Python — Versions + OS

matrix:
  os: [ubuntu-latest, macos-latest]
  python: ['3.10', '3.11', '3.12']
  include:
    - os: windows-latest
      python: '3.12'

Dynamic Matrix

jobs:
  setup:
    runs-on: ubuntu-latest
    outputs:
      matrix: ${{ steps.m.outputs.matrix }}
    steps:
      - id: m
        run: |
          echo 'matrix={"os":["ubuntu","macos"],"node":["18","20"]}' >> $GITHUB_OUTPUT
  build:
    needs: setup
    strategy:
      matrix: ${{ fromJson(needs.setup.outputs.matrix) }}

Pitfalls

Matrix explosion: 4 OS × 5 versions × 3 configs = 60 runners — use exclude and max-parallel
Cost: Each job is a separate runner minute
Cache per combo: Each matrix combo gets its own cache key

Verification

gh run view <run-id> --json jobs --jq '.jobs[].name'

---name: github-actions-matrixdescription: Run test/config combos in parallel with matrix strategy.---# GitHub Actions Matrix Builds**Trigger**: Use when running tests across multiple OS, language versions, or configurations in parallel.## Basic Matrix```yamljobs: test: strategy: matrix: os: [ubuntu-latest, macos-latest, windows-latest] node: [18, 20, 22] runs-on: ${{ matrix.os }} steps: - uses: actions/checkout@v4 - uses: actions/setup-node@v4 with: node-version: ${{ matrix.node }} - run: npm test```This creates 3 × 3 = 9 parallel runners.## Controlling the Matrix### Include```yamlinclude: - os: macos node: 22 # Extra combo not in main grid - os: ubuntu node: 18 coverage: true # Extra variable```### Exclude```yamlexclude: - os: windows node: 22 - os: macos node: 18```### Fail Fast & Concurrency```yamlstrategy: fail-fast: false # Continue other jobs even if one fails max-parallel: 4 # Max concurrent runners matrix: ...```## Real-World Examples### Rust — Multiple Checks```yamlstrategy: matrix: job: - {cmd: "cargo test", os: ubuntu-latest} - {cmd: "cargo clippy", os: ubuntu-latest} - {cmd: "cargo fmt --check", os: ubuntu-latest} - {cmd: "cargo test", os: macos-latest} - {cmd: "cargo test", os: windows-latest}```### Python — Versions + OS```yamlmatrix: os: [ubuntu-latest, macos-latest] python: ['3.10', '3.11', '3.12'] include: - os: windows-latest python: '3.12'```## Dynamic Matrix```yamljobs: setup: runs-on: ubuntu-latest outputs: matrix: ${{ steps.m.outputs.matrix }} steps: - id: m run: | echo 'matrix={"os":["ubuntu","macos"],"node":["18","20"]}' >> $GITHUB_OUTPUT build: needs: setup strategy: matrix: ${{ fromJson(needs.setup.outputs.matrix) }}```## Pitfalls- **Matrix explosion**: 4 OS × 5 versions × 3 configs = 60 runners — use `exclude` and `max-parallel`- **Cost**: Each job is a separate runner minute- **Cache per combo**: Each matrix combo gets its own cache key## Verification```bashgh run view <run-id> --json jobs --jq '.jobs[].name'```

Frequently asked questions

Github Actions Matrix