Windmill Has a Free API: Open-Source Alternative to Retool and Zapier for Developer Workflows

What is Windmill? Windmill is an open-source developer platform that combines internal tools (like Retool), workflow automation (like Zapier/n8n), and job scheduling — all powered by scripts in TypeScript, Python, Go, Bash, or SQL. Self-host for free. Unlimited users, unlimited executions. Quick Start docker compose up -d Or use the CLI: pip install windmill-cli wmill init Scripts (Building Blocks) // TypeScript script export async function main(name: string, count: number = 5) { const results = []; for (let i = 0; i < count; i++) { const res = await fetch(`https://api.example.com/data?name=${name}&page=${i}`); results.push(await res.json()); } return results; } # Python script def main(url: str, timeout: int = 30): import requests response = requests.get(url, timeout=timeout) return {"status": response.status_code, "data": response.json()} Every script is an API endpoint: curl -X POST "https://your-windmill.com/api/w/workspace/jobs/run/p/f/folder/script" \ -H "Authorization: Be