What is Windmill and How It Works

Windmill is an open-source solution for developers looking to automate processes, build internal applications, and quickly expose APIs. It integrates scripting, scheduling, and user interface construction all within one unified platform. Windmill allows you to write small Python, TypeScript, or Go and integrate them into automated or web-triggered workflows. It provides cost-effective internal automation to teams without complicated system infrastructure.

Fundamental Concept.

This is done by treating each script as an independent building block. These blocks can be interconnected into a sequence of automated workflows to be triggered, scheduled, or users can set an event to execute them. It is like a graphical, collaborative, advanced version of cron jobs. Within the organization, developers share a central script repository, control versioning, and manage scripting.

Typical Applications.

Internal Tools.

• Backend scripts can be repurposed into simple dashboards or admin interface.

• Consider an internal web application that provides a button to execute a script that manages user accounts or resets a password.

• This allows teams to safely perform operations without direct access to the database.

Automated Workflows.

• You can execute workflows that run by themselves when triggered by external services, schedules, or APIs.

• Example: When your CRM receives new customer data, Windmill executes a validation script and updates a different system.

• This minimizes the chances of manual handoffs and mistakes.

API Management

• Every script or workflow can be configured to become an endpoint, complete with authentication and logging.

• Internal APIs can be created without building a complete web service.

• This is useful for integrating microservices or for connecting older systems with new ones.

Data Operations

• Scripts can be scheduled so analysts can pull data from APIs, cleanse the data, and then upload it to a database or Google Sheets.

• These workflows can be set to execute on-demand or at specified intervals, keeping dashboards current.

Key Features

• Script-based automation: Python, TypeScript, Go, Bash, and SQL supported.
• Web UI builder: Develop any script to a simple internal web application.
• Triggers: Execute workflows using a schedule, webhook, or an event.
• Collaboration: Cross-team script sharing, versioning, and history tracking.
• Self-hosted or cloud: Either for privacy or convenience.

How to Use Windmill

1. Install or sign up.

Self-host Windmill via Docker or choose the cloud option.

After that, open the dashboard to create scripts and workflows.

2. Write a script.

Pick a programming language (like Python). 

Then, insert logic such as reading an API or updating a database.

Save it to your workspace repository.

3. Build a workflow 

Drag scripts into a flow editor. 

Define inputs, outputs, and conditions. 

Exposing the result as an HTTP API or a UI form is optional. 

4. Trigger and monitor 

Set schedules or connect triggers from other systems. 

Monitor logs and execution results from the dashboard. 

Why Developers Use Windmill 

• It removes the need to build admin tools from scratch. 

• It keeps automation in code, version-controlled, and testable. 

• It provides the speed of no-code tools but with developer flexibility. 

• It’s open-source, so teams can host it privately and modify it as needed. 

In short, Windmill is the developer’s alternative to low-code automation. It gives you control, transparency, and reusability in building internal systems, while reducing setup time and maintenance.