N8n

n8n is an open-source workflow automation platform that competes with Zapier and Make but with a key difference: it is self-hostable and source-available. For agents that need to orchestrate multi-step workflows across services — trigger on webhook, process data, call APIs, update databases — n8n provides both a visual builder and an API for programmatic management. The 400+ built-in integrations cover most common services. The open-source nature means agents can inspect workflow execution, customize nodes, and run without vendor lock-in.

Authentication for the API uses API keys or basic auth for self-hosted instances. n8n Cloud uses API keys. The credential system for connected services is separate — n8n manages OAuth tokens, API keys, and other credentials for integrated services. For agents, this means n8n acts as a credential proxy for workflow execution. The auth model is appropriate for the platform scope. Self-hosted deployments give full control over security configuration.

The API covers workflow management (create, update, activate, deactivate, execute, list), credentials (create, list), and execution history. Workflows are defined as JSON with nodes and connections. Webhook triggers give workflows URLs that accept incoming data. The API allows agents to programmatically create and manage workflows, which is powerful for dynamic automation. The workflow JSON schema is well-defined but complex for sophisticated workflows with branching logic and error handling.

Error handling in workflows uses a node-based error model: each node can have error handling branches. The API returns standard HTTP errors for management operations. Execution history tracks success/failure per workflow run with detailed per-node status. The main operational complexity is debugging failed workflows — agents need to inspect execution logs to identify which node failed and why. Retry mechanics are available at both workflow and node level.

Documentation is comprehensive, covering the API, node reference, workflow design patterns, self-hosting, and community contributions. The API reference is clear. The workflow cookbook provides examples for common automation patterns. The learning curve is moderate — the visual builder is intuitive but complex workflows require understanding n8n's execution model (nodes, connections, expressions, error handling). For agents, the API documentation is the primary entry point.