# LangWatch

> Apache-2.0 LLM tracing, agent tests, evals, gateway

**Category:** AI Agents  
**Pricing:** open-source  
**URL:** https://langwatch.ai  
**GitHub:** https://github.com/langwatch/langwatch  
**Added:** 2026-10-18

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## The Hook

LangWatch is an open-source platform to trace, test, route and govern LLM calls — from the agents you build to the coding assistants your engineers use.

## What's Good

Apache-2.0 (langwatch/langwatch), release langwatch-3.20.1 (2026-10-02). It covers observability, simulation tests for agents and voice agents, evaluations and prompt management, plus coding-agent analytics (sessions, cost per pull request and per team), an OpenAI- and Anthropic-compatible gateway with virtual keys and budgets, and governance views. Self-hosting needs only Node.js for a quick start, with production docs. ★~5k.

## The Catch

It tries to be four products at once, so expect a broad surface that overlaps with Langfuse, Opik and LiteLLM. The production self-host is more than a single Node process. The managed LangWatch Cloud is the commercial path, and README links lean that way.

## Verdict

Worth a look if you want agent tests and an LLM gateway in the same tool as your traces.