Windmill

Windmill is an open-source platform for building internal tools, workflows, and scripts that blurs the line between a low-code builder and a developer platform. You write real code in TypeScript, Python, Go, Bash, SQL, and more, and Windmill handles the orchestration layer: scheduling, webhooks, audit logging, secrets management, and a UI that auto-generates from your function signatures.

The core model is that every script becomes a callable API endpoint, a schedulable job, and an auto-generated web form simultaneously without additional configuration. Workflows connect scripts as directed acyclic graphs with branching, loops, and error handling. A drag-and-drop app builder lets non-technical users trigger scripts and view results through a custom interface.

This combination appeals to engineering teams that want internal tools but are uncomfortable keeping business logic locked inside a no-code platform. The logic stays in version-controlled code, testable and reviewable, while Windmill handles the orchestration and UI.

The self-hosted open-source version is free with unlimited executions and supports up to 10 SSO users. Docker and Kubernetes deployment are both supported. Enterprise pricing starts at $120/month and adds audit logs, SAML, advanced observability, and priority support.

With 4,000+ organizations using it and active development, Windmill has established itself as the most developer-oriented option in the automation and low-code space.