{"data":{"slug":"langwatch","name":"LangWatch","tagline":"Apache-2.0 LLM tracing, agent tests, evals, gateway","category":"agents","categoryName":"AI Agents","url":"https://langwatch.ai","github":"https://github.com/langwatch/langwatch","pricing":"open-source","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.","whatsGood":"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.","theCatch":"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.","addedAt":"2026-10-18","featured":false,"domain":"AI Agents","subSpecialty":"Agents","subcategory":"Evals & Tracing","tags":["self-host","permissive","coding-agents","evals","observability","testing","active"],"capabilities":[],"surfaces":["Self-host"],"ecosystem":["Multi-platform"],"licenseModel":"Apache-2.0","githubStars":4977,"starsPerWeek":31,"access":"free","archived":false,"repo":{"createdAt":"2023-09-09","pushedAt":"2026-10-19","license":"Apache-2.0","archived":false,"checkedAt":"2026-10-19"}},"related":[{"slug":"claude-code","name":"Claude Code","tagline":"Terminal-first coding agent with deep repository context"},{"slug":"cursor","name":"Cursor","tagline":"The AI-first code editor that understands your codebase"},{"slug":"devin","name":"Devin","tagline":"Autonomous AI engineer for defined engineering tasks"},{"slug":"stagehand","name":"Stagehand","tagline":"AI-native browser automation that mixes code and natural language"},{"slug":"browser-use","name":"Browser Use","tagline":"Open-source framework for LLM-driven browser agents"}],"links":{"self":"/api/gems/langwatch","html":"/gems/langwatch","markdown":"/gems/langwatch.md","category":"/api/gems?category=agents","categoryPage":"/stacks/agents"}}