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/j