# Langfuse Observability Plugin for Claude Code

A Claude Code plugin that sends session telemetry, including prompts, tool calls, model generations, token usage and cost, to Langfuse for tracing and observability.

This plugin traces Claude Code sessions and sends the resulting telemetry to Langfuse: user prompts, agent turns, model generations with their token usage and cost, thinking blocks, tool calls, skills, subagents, and pasted or returned images. It covers the claude CLI and the desktop app's Code mode, but not Claude Desktop's separate Chat mode.

It installs as a Claude Code plugin and runs its hook as a uv script, falling back to a plain Python 3.10 or newer install of the Langfuse SDK when uv is unavailable; without a usable runtime it logs the reason and does not block or slow down Claude Code. Langfuse credentials are configured from inside a Claude Code session or passed at install time, and the secret key is stored in the OS keychain rather than in a file.

Website: https://langfuse.com/integrations/developer-tools/claude-code