Reverse Engineering

Experimental

The reverse engineering feature is experimental. Output may require manual adjustments.

Convert existing YAML workflows to TypeScript.

Install

npm install -D flughafen @flughafen/core

CLI

# Convert single workflow → ./flughafen/workflows/ci.ts
npx flughafen reverse .github/workflows/ci.yml

# Convert entire .github directory (workflows + local actions)
npx flughafen reverse  # .github is default

# Preview without writing
npx flughafen reverse --preview

# Custom output directory
npx flughafen reverse --output ./my-project

Output structure:

flughafen/
├── workflows/      # Generated workflow TypeScript files
│   ├── ci.ts
│   └── publish.ts
└── actions/        # Generated local action TypeScript files
    └── my-action.ts

Example

Input: .github/workflows/ci.yml

name: CI
on: [push, pull_request]
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: '22'
      - run: npm test

Output: flughafen/workflows/ci.ts

import { createWorkflow } from '@flughafen/core';

export default createWorkflow()
  .name("CI")
  .on(["push", "pull_request"])
  .job("test", (job) => job
    .runsOn("ubuntu-latest")
    .step((step) => step.uses("actions/checkout@v4"))
    .step((step) => step
      .uses("actions/setup-node@v4", { "node-version": "22" })
    )
    .step((step) => step.run("npm test"))
  );

Local Actions

Local actions in .github/actions/ are extracted and imported:

import myAction from "./actions/my-action";

// ...
.step((step) => step.uses(myAction, { input: "value" }))

Use --skip-local-actions to skip extraction.

Expressions

GitHub Actions expressions are converted to expr() helper calls:

${{ github.ref }}  →  expr("github.ref")

Workflow

1. npx flughafen reverse
2. Review generated TypeScript in ./workflows/
3. npx flughafen build --dry-run to preview YAML
4. npx flughafen build to write files

Use --output ./other-dir to write to a different directory.

Next Steps

• Home - Quick start guide
• API Reference - Full API documentation