Windmill
Open-source platform that turns scripts into workflows, webhooks, and internal apps — Retool meets Temporal.
About
Windmill attacks the script graveyard: the pile of undocumented scripts and cron jobs that only their author can run. You write a script in Python, TypeScript, Go, Bash, or SQL with a plain main function, and Windmill turns it into a version-controlled, observable artifact — triggerable via auto-generated UI, webhook, or schedule, with secrets, permissions, and approvals handled centrally. Flows compose scripts into DAGs with retries, error handlers, suspend/resume, and approval steps.
The positioning is 'open-source Retool / Temporal / Airflow / n8n' and it earns the comparison: 18,000+ stars, a script hub of community contributions, a VS Code extension and CLI for local development, and durable workflow-as-code via @workflow/@task decorators. It is AGPLv3-licensed for the community edition (free to self-host internally; read the license before embedding or offering it as a service), with paid SaaS and enterprise tiers for SSO, audit logs, and support.
What it can do
- Scripts in Python, TypeScript, Go, Bash, SQL, and Docker become runnable endpoints
- Flow builder: DAGs with retries, error handlers, suspend/sleep, approvals
- Auto-generated UIs, webhooks, schedules, and an open API per script
- Centralized secrets (Resources), variables, RBAC, and audit trails
- Workflow-as-code with `@workflow`/`@task` durable execution
- VS Code extension, CLI, Git sync, and a community script hub
Setup
- Self-host with Docker:
docker runthe Windmill image (or use Windmill Cloud). - Write a script with a
mainfunction in Python, TypeScript, Go, Bash, or SQL — locally in VS Code or in the web IDE. - Sync it to Windmill via the CLI or Git integration; dependencies auto-lock.
- Compose scripts into Flows in the low-code builder, or use
@workflow/@taskfor durable workflow-as-code. - Trigger via auto-generated UI, webhook, schedule, or the open API; manage secrets as named Resources.
Prerequisites
Docker (for self-hosting) or a Windmill Cloud account; familiarity with at least one supported scripting language.
Use cases
Works with
Trust score — 9/10
Scored 9/10 (metrics tier, metrics-v1). Evidence: 18,192 GitHub stars (GitHub API), pushed Oct 15 2026; independent reviews corroborate the script-to-endpoint model, the AGPLv3 community license, and the Retool/Temporal/Airflow positioning. Strengths: huge active community, genuinely useful consolidation of scripts/cron into observable platform, generous self-host story. Docked for: (1) AGPLv3 community edition — fine for internal use, check with legal before embedding or SaaS-ifying; (2) open-core upsells (SSO, audit) sit behind paid tiers; (3) app builder is weaker than Retool's. License: AGPLv3 (community); commercial tiers available.
★ 18,192 GitHub stars
How the trust score is built
Full methodology →- Adoption · stars/downloads, log-scaled vs peers
- 8.0/10
- Maintenance · recency, releases, issue load
- 10.0/10
- Openness · license + docs
- 10.0/10
- Manual review · sanity read + red-flag check
- 8.0/10
- · Adoption 8: starScore from 18,192 stars on windmill-labs/windmill
- · Maintenance 10: pushed 2026-10-15 (recency 10); very active
- · Openness 10: AGPLv3 is OSI-approved (0.7*10) + docs verified at windmill.dev (0.3*10)
- · Manual 8: independent reviews corroborate the script-to-endpoint model, the AGPLv3 community license, and the Retool/Temporal/Airflow positioning; docked for AGPL copyleft (check before embedding/SaaS), open-core upsells, weaker app builder than Retool
Sources
Every fact above was checked against these sources. Where a claim comes from the provider and couldn't be independently verified, the text says so.