LangSmith

license

Proprietary

source

closed

platform

proprietary(no public source for LangSmith itself)

LangSmith the observability/eval platform is closed/proprietary; only the LangChain/LangGraph frameworks (separate registry entries) are open. Self-host/BYOC are licensed deployments of closed software, not source-available.

• https://www.langchain.com/langsmith recorded 2026-08-13

  The product page. Its Open Source Frameworks menu lists deepagents and the LangChain/LangGraph line; LangSmith is not among them and no repository is linked for it. The FAQ reads "Can I self-host LangSmith? Yes. LangSmith offers managed cloud, bring-your-own-cloud (BYOC), and self-hosted options for teams with data residency requirements", and the self-host copy describes shipping "SmithDB inside your VPC" as "three stateless components on object storage and Postgres" - a licensed deployment of closed software rather than a published source tree.

The default observability and evaluation platform for the very widely used LangChain ecosystem, placed at 4 on that ecosystem reach plus a published enterprise roster: the vendor page names Klarna, Lyft, LinkedIn, Coinbase, Nvidia, Workday, Rakuten, Elastic and Harvey, and carries no quantitative user, customer or download count anywhere. Because nobody has published a count, the level rests on reported traction and no numeric reach is claimed. The band is deliberately not taken from the langsmith PyPI package: langsmith is a hard dependency of langchain-core, so its download count measures LangChain installs rather than LangSmith use, and a transitive dependency of a different product measures that other product.

• https://www.langchain.com/langsmith recorded 2026-08-14

  Named enterprise roster still published - Klarna, Lyft, LinkedIn, Coinbase, Nvidia, Workday, Rakuten, Elastic and Harvey among them - and positioned as the LangChain-ecosystem observability platform. No user, customer or download count is stated anywhere on the page, and no "25+" figure appears. The URL now redirects to /langsmith/observability.

A mature, broad feature matrix: framework-native tracing with Python, TypeScript, Go and Java SDKs; monitoring with cost tracking, LLM-as-judge evaluations and alerts; evaluation and scoring; prompt and dataset workflows; and deployment, fleet and sandbox tooling for agents. That is level with Langfuse at 4. The product is closed source, but capability is assessed independently of openness.

• https://www.langchain.com/langsmith recorded 2026-08-13

  Product pillars named on the page - Observability ("See exactly what your agents are doing"), Evaluation ("Score and improve agent performance"), Agent Infrastructure Deployment and Sandboxes. Tracing offers "Native tracing for popular agent frameworks and OpenTelemetry SDKs"; Monitoring lists cost tracking, "Online LLM-as-judge and code evals", tool and agent trajectory monitoring, and webhook/PagerDuty alerts.