Hippycampus

What it is

A LangChain-based server that loads OpenAPI specifications at runtime and turns them into callable tools, reachable either from an MCP client over SSE or from a Langflow canvas through its bundled components. It also runs as a plain CLI, which is the quickest way to see whether a given spec parses before wiring anything up.

What you get

• Dynamic loading of an OpenAPI specification from a URL, so an API becomes usable without a purpose-built server for it
• An MCP server mode over SSE — uv run hippycampus-server --transport sse --port 8000, reachable at http://localhost:8000/sse
• A CLI mode, uv run hippycampus-cli, for debugging spec parsing and agent interaction before involving a client
• Two Langflow components: OpenApi Service for loading a spec, and Hippycampus MCP Server for connecting over SSE

Requirements

Python 3.12.9 and the UV package manager; create a virtual environment, then uv pip install -e ., and uv pip install langflow if you want the visual side. A Google AI Studio API key in GOOGLE_API_KEY — authentication errors almost always mean it is unset. For Langflow, export LANGFLOW_COMPONENTS_PATH pointing at the repository's langflow/components directory, start the MCP server before Langflow, and restart Langflow if the components do not appear. Specs in the wild are not always correct: the official XKCD swagger declares its comic_id as a number rather than an integer, and the repository ships a corrected copy in its test folder.

Setup effort

Build from source — git clone https://github.com/cromwellian/hippycampus

Requires

• Python 3.12.9
• GOOGLE_API_KEY in your environment