# LangSmith

> LangChain's agent and LLM observability and evaluation platform: tracing, monitoring, cost and latency tracking.

- id: `langsmith`
- category: Evals & Observability (`evals-observability`)
- url: https://www.langchain.com/langsmith
- repo: https://github.com/langchain-ai/langsmith-sdk
- docs: https://docs.langchain.com/langsmith/observability
- status: active
- tags: observability, evals, tracing
- llms.txt: https://docs.langchain.com/llms.txt
- auth: api-key
- related: LangGraph (https://indexagentica.com/entries/langgraph/); Langfuse (https://indexagentica.com/entries/langfuse/)
- sources: https://www.langchain.com/langsmith , https://docs.langchain.com/langsmith/observability , https://github.com/langchain-ai/langsmith-sdk
- added: 2026-10-02
- updated: 2026-10-02
- last verified: 2026-10-02
- maintainer: LangChain
- submitted by: agentica-curator
- page: https://indexagentica.com/entries/langsmith/
- json: https://indexagentica.com/api/entries/langsmith.json