github-actions-author

GitHub Actions Author

Contract

Inputs:

• Repository root or target workflow file
• Desired workflow behavior, triggers, runtimes, and deployment target
• Optional secrets, environments, runner constraints, and matrix strategy

Outputs:

• Workflow YAML or patch summary
• Documentation-backed rationale for non-obvious choices
• Security and validation checklist

Creates/Modifies:

• May create or edit .github/workflows/*.yml
• Does not add secrets or deploy without approval

External Side Effects:

• Reads official GitHub documentation when syntax, permissions, or product behavior may have changed
• May query workflow metadata with GitHub CLI
• Does not dispatch, rerun, or cancel workflows without approval

Confirmation Required:

• Before writing workflow files when requirements are unclear
• Before adding deployment, release, publish, or secret-consuming behavior
• Before dispatching or rerunning workflows

Delegates To:

• testing-cicd-init for first-pass TypeScript test infrastructure
• gh-fix-ci when a workflow is failing on a PR
• git-safety when workflows touch credentials, tokens, or publish steps

Workflow

1. Discover existing CI shape:

   find .github/workflows -maxdepth 1 -type f 2>/dev/null
   gh workflow list
   git status -sb
   

2. Read relevant local context:

   • Existing workflow files
   • package.json, lockfiles, workspace config, test scripts
   • Deployment docs or release conventions

3. Ground version-sensitive choices in official GitHub docs:

   • Workflow syntax, triggers, contexts, expressions
   • GITHUB_TOKEN permissions
   • pull_request vs pull_request_target
   • OIDC, environments, deployment protection rules
   • Cache, artifacts, reusable workflows, matrices, concurrency

4. Check action versions before adding or bumping common actions:

   gh release view --repo actions/checkout --json tagName --jq '.tagName'
   gh release view --repo actions/setup-node --json tagName --jq '.tagName'
   gh release view --repo oven-sh/setup-bun --json tagName --jq '.tagName'
   

5. Author with safe defaults:

   • Pin permissions at workflow or job level; default to contents: read.
   • Use pull_request for untrusted code. Use pull_request_target only for metadata/comment workflows that do not check out or execute fork code.
   • Pass untrusted event data through environment variables before shell use.
   • Use concurrency for expensive or deploy workflows.
   • Use cache keys that include lockfile hashes.
   • Avoid printing secrets or full tokens.
   • Separate CI, release, and deployment workflows when permissions differ.

6. Validate locally when possible:

   git diff -- .github/workflows
   gh workflow view <workflow-name-or-id> --yaml
   

   Run actionlint if already installed. Do not install new global tools unless the user asks.

7. Final output:

   • Files changed
   • Trigger behavior
   • Permissions and secret boundaries
   • Validation performed
   • Remaining manual setup such as secrets or environments

Security Review Checklist

• No hardcoded secrets, tokens, credentials, or private URLs.
• Job permissions are minimal and explicit.
• Fork PRs cannot access secrets or execute trusted-token publish paths.
• Shell steps quote variables and avoid direct interpolation of issue/PR text.
• Third-party actions are current and reputable; pin to SHA for sensitive workflows or untrusted supply-chain surfaces.
• Deployment jobs use environments when human approval or environment-scoped secrets are needed.
• Release/publish jobs run only on trusted refs or signed/manual dispatch paths.