n8n is a source-available workflow automation tool that connects APIs, databases, and SaaS products through a node-based visual editor. It sits in the same category as Zapier and Make, but runs as a self-hostable Node.js application backed by PostgreSQL, SQLite, or MySQL for workflow state and execution history.
Workflows are directed graphs of nodes, where each node is a typed integration (HTTP Request, Postgres, Slack, OpenAI, etc.) or a control primitive (IF, Switch, Merge, Loop). Execution can be triggered by webhooks, cron, polling, or manual invocation, and the Code node lets you drop into JavaScript or Python when the built-in nodes are not enough. More recent releases add a LangChain-based AI agent node set for chaining LLM calls, tools, and vector stores inside the same graph.
n8n is distributed under the Sustainable Use License, a source-available “fair-code” license that permits internal and personal use but restricts hosting it as a competing commercial service. The Enterprise edition adds SSO, RBAC, external secrets, and log streaming on top of the community build. For teams that want to avoid Zapier’s per-task pricing or keep sensitive data on their own infrastructure, n8n is the usual self-hosted alternative, alongside Node-RED (more IoT-oriented), Windmill, and Temporal for code-first durable workflows.