Install a language runtime (Node.js, Python, or Go) and restore the dependency cache in a single uses: call. Based on the official GitHub Docs composite action tutorial — extended with multi-runtime support, input validation, and job summary.

Status: Stable

Quick start

# Node.js
- uses: your-org/actions/setup-env@v1
  with:
    runtime: node

# Python
- uses: your-org/actions/setup-env@v1
  with:
    runtime: python
    version: '3.12'

# Go
- uses: your-org/actions/setup-env@v1
  with:
    runtime: go
    version: '1.22.x'

How it works

inputs.runtime (node | python | go)
        │
        ▼
Resolve version (use inputs.version or default per runtime)
        │
        ├── node   → actions/setup-node → ~/.npm cache → npm ci
        ├── python → actions/setup-python → ~/.cache/pip cache → pip install
        └── go     → actions/setup-go → ~/go/pkg/mod cache → go mod download
        │
        ▼
outputs.runtime_version (exact installed version)
outputs.cache_hit        (true | false)

Inputs

Input	Type	Required	Secret	Default	Description
`runtime`	choice	Yes	No	—	`node` / `python` / `go`
`version`	string	No	No	Runtime default	Version to install (e.g. `20.x`, `3.12`, `1.22.x`)
`enable_cache`	boolean	No	No	`true`	Restore dependency cache
`working_directory`	string	No	No	`.`	Directory with lock file
`install_dependencies`	boolean	No	No	`true`	Run install after setup

Runtime version defaults:

Runtime	Default version
node	`20.x`
python	`3.12`
go	`1.22.x`

Outputs

Output	Description
`runtime_version`	Exact installed runtime version
`cache_hit`	`true` if the dependency cache was restored

Variables and secrets

No secrets required. All inputs are plain variables.

# What flows in (all safe to log):
# inputs.runtime   → 'node', 'python', or 'go'
# inputs.version   → '20.x', '3.12', etc.
#
# Cache keys are derived from lock file hashes — never contain credentials

Permissions

permissions:
  contents: read   # checkout only

Idempotency

Idempotent — running twice restores the same cache (or rebuilds it if the lock file changed). The setup tools are also idempotent.

Full example — matrix across runtimes

name: Multi-runtime CI

on:
  push:
    branches: [main]
  pull_request:

permissions:
  contents: read

jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        include:
          - runtime: node
            version: '20.x'
          - runtime: node
            version: '22.x'
          - runtime: python
            version: '3.12'
          - runtime: go
            version: '1.22.x'

    steps:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683  # v4.2.2

      - name: Setup ${{ matrix.runtime }} ${{ matrix.version }}
        id: setup
        uses: your-org/actions/setup-env@v1
        with:
          runtime: ${{ matrix.runtime }}
          version: ${{ matrix.version }}

      - name: Print installed version
        run: echo "Installed ${{ matrix.runtime }} ${{ steps.setup.outputs.runtime_version }}"

      - name: Run tests (node)
        if: matrix.runtime == 'node'
        run: npm test

      - name: Run tests (python)
        if: matrix.runtime == 'python'
        run: python -m pytest

      - name: Run tests (go)
        if: matrix.runtime == 'go'
        run: go test ./...