GitHub Actions Workflow Generator

How to use it

1. Name the workflow and pick a stack preset — each job then opens with cited checkout and setup steps for that language.
2. Enable triggers: push and pull_request take branch filters, schedule takes one 5-field UTC cron per line, workflow_dispatch adds the manual run button.
3. Add jobs and give each an id and a runs-on label; the suggestions are the GitHub-hosted runners, and self-hosted labels stay legal free entry.
4. Attach your own steps — an action reference with with: inputs, or a shell command — plus env rows where the job needs variables.
5. Read the constraint strip, then copy or download the YAML and commit it under .github/workflows on your default branch.

Assemble a GitHub Actions workflow file from parts you pick: triggers, a language preset, jobs, steps and env rows. The builder validates what GitHub actually enforces — job-id grammar, the 5-field schedule syntax, unique ids — and prints least-privilege token permissions by default. Everything is composed on this device; the YAML lands in your clipboard, not on a server.

How it works

The form compiles to a single document tree in the key order the workflow syntax reference documents: name, on, permissions, concurrency, jobs. Validation runs first and collects every finding in one pass — a bad job id does not hide an invalid cron — and splits results into refusals, which block emission, and advisories, which ride alongside the finished YAML in the constraint strip.

Identifiers are checked against GitHub's published grammar rather than guessed: a job id must open with a letter or underscore and stay within letters, digits, hyphen and underscore, ids must be unique inside one file, and env keys follow the shell-variable shape because the runner exports them into the job's process environment. Unknown runs-on labels are deliberately a warning, not an error — self-hosted and larger-runner labels are real.

Schedule lines pass through the same constraint model the cron helper on this site ships: macros like @daily are refused with their five-field rewrite printed in the message, each field is range-checked positionally, day-of-week 7 is rejected because the documentation defines 0 through 6, and a cadence tighter than five minutes draws an advisory quoting the observed gap.

Emission goes through the yaml library with folding disabled, then every cron scalar is forced into single quotes — an expression starting with an asterisk would otherwise collide with YAML's alias indicator, and quoting matches how the documentation prints schedules. Values that could re-parse as numbers or booleans come out double-quoted automatically, so the file always reads back as the strings you typed.

Two safety rails are on by default. The permissions preset writes contents: read, the least-privilege GITHUB_TOKEN setting the security-hardening guide recommends, and unchecking it simply omits the key so your repository default applies. Separately, a credential-shaped value typed into an env or with row triggers a warning that names the key and suggests the secrets context — and share links exclude env and with values structurally, so a pasted token cannot ride out in a URL.

Examples

Node CI on push and pull_request to main

name: CI
on:
  push:
    branches:
      - main
  pull_request:
    branches:
      - main
permissions:
  contents: read
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Check out repository
        uses: actions/checkout@v7
      - name: Set up Node.js
        uses: actions/setup-node@v7
        with:
          node-version: lts/*
          cache: npm
      - name: Install dependencies
        run: npm ci
      - name: Run tests
        run: npm test

Python nightly at 02:30 UTC with a manual trigger

name: Nightly checks
on:
  schedule:
    - cron: '30 2 * * *'
  workflow_dispatch: {}
permissions:
  contents: read
jobs:
  nightly:
    runs-on: ubuntu-latest
    steps:
      - name: Check out repository
        uses: actions/checkout@v7
      - name: Set up Python
        uses: actions/setup-python@v7
        with:
          python-version: 3.x
      - name: Upgrade pip
        run: python -m pip install --upgrade pip
      - name: Install dependencies
        run: pip install -r requirements.txt
      - name: Run tests
        run: pytest

Manual release with concurrency and a custom step

name: Release
on:
  workflow_dispatch: {}
permissions:
  contents: read
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
jobs:
  release:
    runs-on: ubuntu-latest
    steps:
      - name: Check out repository
        uses: actions/checkout@v7
      - name: Build release artifact
        run: make release

Every example on this page is executed against the same engine that powers the tool, on every build.

Common errors

on.schedule takes plain 5-field cron only — `@daily` becomes `0 0 * * *`.

Vixie shorthands never reached the Actions grammar. The refusal prints the equivalent five fields ready to paste; only @reboot gets no rewrite because nothing reboots, and the message points at workflow_dispatch instead.

Job id `build job` is invalid — an id starts with a letter or _ and uses only letters, digits, - and _.

Job ids become YAML keys and expression references, so GitHub restricts their alphabet. Spaces are the usual surprise — build-job and build_job are both fine.

No trigger is enabled — turn on at least one of push, pull_request, schedule or workflow_dispatch.

A workflow with an empty on: block can never start, so the builder refuses to print one. workflow_dispatch is the smallest honest choice while you are still drafting.

This schedule can fire runs 4 minutes apart — GitHub's shortest schedule interval is 5 minutes.

The YAML still emits because the syntax is legal; the timetable is what GitHub will not honor. Widen the step to */5 or more so the committed cadence matches what the platform delivers.

The env value of `AWS_ACCESS_KEY_ID` looks like a credential — use ${{ secrets.AWS_ACCESS_KEY_ID }} and keep the real value in the repository's Actions secrets.

Workflow files are committed plaintext, so a pasted key would land in git history. The warning names the key, never repeats the value, and share links from this page structurally exclude env and with values either way.

Keyboard shortcuts

/

Focus the workflow name (outside any field).

⌘/Ctrl + Enter

Rebuild the YAML from the current form.

⌘/Ctrl + S

Download the generated file as workflow.yml.

⌘/Ctrl + C

With no text selected, copy the workflow YAML.

⌘/Ctrl + Shift + C

Force the YAML copy while a selection is active.

t

Cycle the site theme (inactive while typing in a field).

? or ⌘/Ctrl + /

Show the shortcut overlay.

Esc

Dismiss the topmost dialog.