GitHub Actions

Use this skill when authoring or reviewing GitHub Actions workflows.

Workflow

Inspect existing triggers, permissions, concurrency, secrets, environments, and repository rules before editing.
Define the smallest job permissions, cache key/restore strategy, artifact retention, and validation needed for the change.
Resolve every third-party action release to its full 40-character commit SHA. Keep the human-readable release tag only as an adjacent comment; never use a mutable @vN, branch, or tag as the executable ref.
Verify the owner, release tag, and commit provenance before accepting a new or updated SHA. Advance pins only through the repository's controlled dependency-update or reviewed maintenance process.
Validate YAML, changed workflow paths, and representative local or CI commands before relying on automation.

# actions/checkout v4.2.2
uses: actions/checkout@<verified-40-character-commit-sha>

The SHA is the executed supply-chain boundary. A major-version tag such as @v4 is a mutable Git ref and is not a safe default for credential-bearing CI.
Do not copy a SHA from an unverified issue, example, or third-party workflow. Resolve the intended official release, review its provenance, and record the release tag in the comment.
Treat third-party action pin changes as dependency updates: review the diff and release notes, run the workflow's relevant validation, and retain the review evidence.

Inspect the target repository before making changes.
Prefer existing project patterns, declared package managers, and documented validation commands.
Do not expose secrets, credentials, private user data, or production account identifiers in source, examples, or logs.
When external APIs or current vendor behavior matter, verify against official docs before implementation.

Source classification: official-docs-reference
This is a LocalSetup-native skill written from project workflow requirements and public/official documentation routing.