FastAPI Langgraph Starter — AI skill for Claude Code

FastAPI LangGraph Starter 🚀

A modern, production-grade template for building stateful AI agents using **FastAPI**, **LangGraph**, and **uv**.

🌟 Key Highlights

• FastAPI Backend: Async, high-performance web service with automated OpenAPI Swagger UI.
• LangGraph Agent Workflow: Dynamic cyclic graph workflows with conditional tool routing and SQLite session checkpointer persistence (thread_id).
• Multi-LLM Provider Support: Out-of-the-box support for Anthropic Claude, Google Gemini, and local Ollama models.
• Real-Time Streaming: Server-Sent Events (SSE) emitting token streams and tool lifecycle events (tool_start, tool_end).
• Tool Registry: Dynamic tool discovery, registration, and per-request tool filtering.
• Modern Python Tooling: Fast dependency resolution with uv, code linting with ruff, and testing with pytest.

📂 Quick Links

• Backend Documentation & Setup Guide
• Client Integration Example (TypeScript)

🚀 Getting Started

Navigate to the `backend` folder and get started:

cd backend
cp .env.example .env
uv sync --all-groups
uv run app

Visit the interactive Swagger API documentation at: [http://localhost:8000/docs](http://localhost:8000/docs).