Windmill
Windmill is an open-source developer platform for internal code: scripts, workflows, background jobs and generated UIs, in Python, TypeScript, Go, Bash, SQL and more. Scripts compose into flows and run from schedules, webhooks, HTTP routes, Kafka, WebSockets or email. Built from source it is AGPLv3; its ready-made Community Edition images include proprietary code that may be used internally but not resold. It runs on Docker Compose or Kubernetes.
What does Windmill do?
Windmill is an "open-source developer platform for internal code: APIs, background jobs, workflows and UIs", and a "self-hostable alternative to Retool, Pipedream, Superblocks and a simplified Temporal." You write scripts in Python, TypeScript, Go, Bash, SQL, GraphQL, PowerShell, Rust, PHP, C#, Java or Ansible; "scripts are turned into sharable UIs automatically" and "can be composed together into flows."
Triggers include "schedules, webhooks, HTTP routes, Kafka, WebSockets, emails, and more." It has a web IDE, a command line, a VS Code extension, two-way Git sync and AI-assisted development. Jobs run in nsjail sandboxes with one encryption key per workspace, and the README puts the overhead of a job at about 50 milliseconds and a lightweight Deno job at about 100 milliseconds, its own figures. Integrations are resources imported from WindmillHub. AI agents and MCP are not described in the README.
Key facts
- Licence: AGPLv3 unless otherwise specified. Backend code under the enterprise compile flag and front-end code behind a licence check are proprietary. The client libraries and the OpenAPI and OpenFlow specs are Apache-2.0.
- A build made without the enterprise flag is open source under AGPLv3, per the LICENSE.
- The ready-made Community Edition images and binaries include proprietary code: free to use and redistribute as is, but not to sell, resell, run as a managed service, modify or wrap without an agreement.
- Scripts in Python, TypeScript, Go, Bash, SQL, GraphQL, PowerShell, Rust, PHP, C#, Java and Ansible, turned into UIs and composed into flows.
- Triggers: schedules, webhooks, HTTP routes, Kafka, WebSockets and email.
- nsjail sandboxing and one encryption key per workspace; about 50 ms of job overhead by the README's own measure.
- Install: Docker Compose with three files, or Kubernetes with Helm; needs Postgres; about 1 worker per vCPU with 1 to 2 GB of RAM.
- Windmill Labs sells dedicated instances, commercial support and an Enterprise Edition. Latest tagged release when read: v1.814.0 on 2026-09-17; 17,958 stars.
What does it replace, and where does it fall short?
Windmill replaces Zapier and Make for a developer team whose automations are code: scripts in the language of their choice, composed into flows, triggered by webhooks, schedules or queues, with generated UIs for colleagues. It is the pick for code-first automation on the open-source alternatives to Make page.
Where it falls short: it is built for developers, not for non-technical staff wiring apps together, and it has no AI agent features in its README. The licence needs care: building from source gives AGPLv3, but the convenient Community Edition images include proprietary code you may not resell or offer as a service. For a no-code builder, Activepieces.
How does Windmill run?
Docker Compose with the three files the README names, a compose file, a Caddyfile and an .env, or Kubernetes with the Helm chart; both need Postgres. The README's rule of thumb is one worker per vCPU with 1 to 2 GB of RAM. Windmill Labs sells dedicated instances, commercial support and an Enterprise Edition with a licence key.
Who is Windmill for?
A developer team automating internal work in code, across many languages, with generated tools for the rest of the company. A team of non-developers should pick Activepieces or n8n.
What limits does the README state?
From the README: the Community Edition is free to use internally, and commercial redistribution or managed services need a commercial licence; a commercial licence is also needed to sell a feature built on the Community Edition; some metrics are Enterprise only.
Questions people ask
Is Windmill open source?
Built from source without the enterprise flag, yes: AGPLv3, by its LICENSE. The ready-made Community Edition images and binaries include proprietary code and may be used and redistributed as is, but not sold, run as a managed service, modified or wrapped without an agreement. This site labels the source open source and states that split.
Which languages can Windmill scripts use?
Python, TypeScript, Go, Bash, SQL, GraphQL, PowerShell, Rust, PHP, C#, Java and Ansible, by the README. Each script becomes a shareable UI automatically, and scripts compose into flows that can mix languages step by step.
What can trigger a Windmill workflow?
Schedules, webhooks, HTTP routes, Kafka, WebSockets and emails, among others, by the README. Workflows can also be started from the UIs Windmill generates for each script, or through its API from other systems.
How does Windmill compare with Make?
Windmill is code-first: scripts in many languages composed into flows, with generated UIs and developer tooling, self-hosted. Make is a hosted visual platform for connecting apps and AI models. The open-source alternatives to Make page compares Windmill with n8n, Activepieces, Dify, Langflow and Huginn.
Do I need a commercial licence to use Windmill at work?
Not to use the Community Edition as is inside your organisation or to call its APIs as is, by the README. You need one to sell a feature built on it, redistribute it commercially, or run it as a managed service.
Sources
- Windmill README and LICENSE: github.com/windmill-labs/windmill, read 2026-09-17.
Compared with the others
On the open-source alternatives to Zapier page, Windmill is the pick for code-first automation for developers. Scripts in Python, TypeScript, Go, Bash, SQL and more, composed into flows with generated UIs, triggered by schedules, webhooks, Kafka or email.
Also on that page: Activepieces for a no-code builder under mit, n8n for the largest integration library, Dify for ai-first workflows and agents.
On the open-source alternatives to Make page, Windmill is the pick for code-first automation for developers. Scripts in Python, TypeScript, Go, Bash, SQL and more, composed into flows with generated UIs, triggered by schedules, webhooks, Kafka or email.
Also on that page: n8n for the largest integration library, Activepieces for a no-code builder under mit, Langflow for visual ai flows as apis or mcp tools.
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Added September 17, 2026. Every claim above comes from the project's README, LICENSE or model card, read on September 17, 2026, or from the GitHub API on the date shown in the panel. Found an error? Write to reveneau@licheo.com and it is fixed in the next weekly pass. Repository: github.com/windmill-labs/windmill.
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