Langflow API
Langflow's FastAPI-based REST API exposes every capability of a running Langflow server — running flows, building flows, managing projects, files, users, API keys, MCP servers, messages and sessions, traces, starter projects, and an OpenAI-compatible Responses endpoint. Authentication is via the `x-api-key` header or query parameter. An interactive OpenAPI 3.1 spec is served at `/docs` and `/openapi.json` on every deployment.
Langflow API is one of 13 APIs that Langflow publishes on the APIs.io network, described by a machine-readable OpenAPI specification.
Tagged areas include AI, Agents, Workflows, Low-Code, and LangChain. The published artifact set on APIs.io includes API documentation, authentication docs, an OpenAPI specification, and a JSON-LD context.