Open-source Windmill MCP alternatives
Windmill's MCP server is open source, so you can read how it runs and manages scripts, flows, jobs, and schedules and exposes your own scripts as tools before wiring it to an agent. The alternatives here publish their code too, which matters when an automation server can trigger real work.
These are the open-source automation and execution servers people compare against Windmill, ordered roughly by reach. Most run locally, some also offer a hosted endpoint, and all let you audit the source and pin a version.
The 8 best open-source alternatives
Activepieces is open source and turns its automation pieces and flows into agent tools through a per-project remote endpoint. The pieces library is readable before you grant trigger access.
Set up Activepieces →Built around 800+ open-source nodes, the n8n community server lets an agent design, validate, and deploy workflows, with the whole node catalog open to inspect.
Set up n8n →Flow-based and fully open, the Node-RED server reads, builds, and updates flows, manages nodes, triggers inject nodes, and inspects runtime state via the Admin API.
Set up Node-RED →For durable execution, the open-source Temporal server manages workflows, signals, queries, batch operations, and schedules. The source confirms how it drives a cluster.
Set up Temporal →- ComposioOfficial
Composio's universal server is open source and connects an agent to 500+ apps through one OAuth endpoint. The repo shows which connections it manages before you grant access.
Set up Composio → - InngestOfficial
Inngest publishes its Dev Server MCP, which sends events, invokes functions, monitors runs, and searches docs against a dev server, a code-first model close to Windmill's and open to audit.
Set up Inngest → - PipedreamOfficial
Pipedream's open server connects an agent to 2,800+ apps and 10,000+ prebuilt actions with managed OAuth and per-app endpoints, the code available when you need app glue.
Set up Pipedream → - Trigger.devOfficial
The closest developer platform, also open: Trigger.dev's server scaffolds projects, triggers and debugs background tasks, deploys to any environment, and runs TRQL queries, matching Windmill's code-first shape.
Set up Trigger.dev →
How to choose
Windmill's own server is already open source, so the choice is which open codebase fits your model. Trigger.dev and Inngest are closest for code-first execution, Temporal for durable orchestration, and n8n, Node-RED, or Activepieces for visual builders. Composio and Pipedream are the open option when you mainly need SaaS connectors. Read the repo before granting trigger or deploy access.
FAQ
- Is the Windmill MCP server open source?
- Yes. Windmill publishes its official server, so you can read the code, fork it, and pin a version. Every alternative on this page is open source as well, which is the focus of this cut.
- Which open-source alternative is closest to Windmill?
- Trigger.dev is the nearest developer platform: it scaffolds projects, triggers background tasks, and deploys from open code, a code-first shape like Windmill's. Inngest matches the event-driven model, and Temporal covers durable orchestration. n8n and Node-RED solve a more visual problem.