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Alex Spinov
Alex Spinov

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Windmill Has a Free Open-Source Developer Workflow Platform

#python #opensource #webdev #automation

Windmill is a free, open-source developer platform for building internal tools, workflows, and scripts. It's like a self-hosted Retool + Zapier combined.

What Is Windmill?

Windmill lets you create scripts, workflows, and UIs that run on your infrastructure. Write in Python, TypeScript, Go, Bash, or SQL — Windmill handles scheduling, permissions, and the UI.

Key features:

  • Scripts in Python, TypeScript, Go, Bash, SQL, GraphQL
  • Visual workflow builder
  • Auto-generated UIs for any script
  • Scheduling (cron)
  • Webhooks
  • Approval flows
  • Secret management
  • Version control (Git sync)
  • Audit logs
  • Self-hostable

Quick Start

Docker 

curl https://raw.githubusercontent.com/windmill-labs/windmill/main/docker-compose.yml \
  -o docker-compose.yml
docker compose up -d
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Open http://localhost:8000. Start building.

Cloud (free tier)

Sign up at app.windmill.dev.

Write a Script 

# main.py — Windmill auto-generates UI inputs for function parameters
import requests

def main(url: str, timeout: int = 30):
    """Check if a website is up"""
    response = requests.get(url, timeout=timeout)
    return {
        "status": response.status_code,
        "response_time_ms": response.elapsed.total_seconds() * 1000,
        "is_up": response.status_code == 200
    }
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Windmill automatically creates a form with url (text input) and timeout (number input). Non-developers can run it.

Build Workflows

Chain scripts visually:

Fetch Data (Python) → Transform (TypeScript) → IF condition → Save to DB (SQL)
                                                            → Send Alert (Slack)
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Auto-Generated UIs

Every script gets a free UI:

  • Text inputs for strings
  • Number inputs for integers
  • File uploads for binary data
  • Dropdowns for enums
  • Date pickers for datetime
  • Toggle for booleans

No frontend code needed.

Windmill vs Alternatives

Feature Retool n8n Windmill
Scripts Limited Code nodes Full (Py/TS/Go/Bash/SQL)
Workflows No Yes Yes
Auto UI No No Yes
Self-host Paid Free Free
Git sync Limited No Yes
Approvals Yes No Yes
Cost $10+/user $0 (self-host) $0 (self-host)

Scheduling 

# Run every hour
0 * * * *

# Run daily at 9 AM
0 9 * * *

# Run every 5 minutes
*/5 * * * *
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Set schedule in the UI. Windmill handles execution, retries, and logging.

Free Cloud Tier

Feature Free Pro
Users 1 Unlimited
Executions 1,000/month 10K+
Scripts Unlimited Unlimited
Workflows Unlimited Unlimited
Workers 1 Custom

Who Uses Windmill?

With 11K+ GitHub stars:

  • Ops teams building internal tools
  • Data teams automating ETL pipelines
  • Developers replacing cron jobs
  • Companies wanting Retool alternative

Get Started

  1. Docker compose up
  2. Write a script in any language
  3. Get auto-generated UI
  4. Schedule it

Internal tools in minutes, not weeks.

Need web data for your workflows? Check out my web scraping tools on Apify — extract data from any website and pipe it into Windmill. Custom solutions: spinov001@gmail.com

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