Composite actions for reusable multi-step logic within a repo

The same sequence of 4-5 steps appears in multiple jobs within a repository (e.g., checkout + setup Node + restore cache + install). Reusable workflows add an extra job layer and have input type limitations.

Create a composite action in .github/actions/setup-node:

# .github/actions/setup-node/action.yml
name: Setup Node
description: Checkout, setup Node, restore cache, and install dependencies
inputs:
  node-version:
    description: Node.js version
    required: false
    default: '20'
runs:
  using: composite
  steps:
    - uses: actions/checkout@v4
    - uses: actions/setup-node@v4
      with:
        node-version: ${{ inputs.node-version }}
    - uses: actions/cache@v4
      with:
        path: node_modules
        key: ${{ runner.os }}-nm-${{ hashFiles('package-lock.json') }}
    - run: npm ci
      shell: bash

Use it in any job:

steps:
  - uses: ./.github/actions/setup-node
    with:
      node-version: '22'

Composite actions run in the same job, share the same workspace and environment, and do not add extra job overhead. They are simpler than reusable workflows for step-level reuse.