LangSmith Observability is LangChain's platform for seeing what AI agents and LLM applications actually do in production. It captures traces of every model call, tool call, retrieval step and agent decision, then lets you inspect, compare, evaluate and alert on them.
It is framework-agnostic: you can trace LangGraph and LangChain applications, or instrument any stack with the Python, TypeScript, Go or Java SDKs.
Core capabilities
Tracing — hierarchical traces show each run, its inputs/outputs, latency, token usage and errors, including nested tool and retrieval calls.
Agent visibility — follow an agent's reasoning and tool use across steps to find where it went wrong.
Evaluation — build datasets from real traces, run offline and online evaluators, and compare prompt/model versions.
Prompt management — version, test and deploy prompts from a central registry.
Monitoring and alerts — dashboards for latency, error rate, cost and quality; alert when behavior drifts.
Framework and SDK coverage — native integrations for LangGraph/LangChain plus OpenTelemetry-style instrumentation for other stacks.
Self-hosting and BYOC — Enterprise can run LangSmith in their own Kubernetes cluster on AWS, GCP or Azure so data never leaves their environment.
Low overhead — the SDK uses an async callback handler and a distributed collector, so tracing does not block application requests; if LangSmith has an incident, the agent keeps running.
Data and privacy
LangSmith cloud data is stored in GCP us-central-1. LangChain states it does not train on customer data, and customers retain rights to their data. Enterprise self-hosted/BYOC options exist for compliance-sensitive teams.
Getting started
Create a LangSmith account at smith.langchain.com.
Install the SDK for your language and set the API key.
Wrap your app or agent; traces appear in the project view.
Build a dataset from interesting traces and add evaluators.
Set up monitoring dashboards and alerts for production.
For self-hosting, follow the Kubernetes deployment guide.
Pricing
LangSmith has a free tier for development and small-scale production; paid plans scale with trace volume, and Enterprise adds self-hosting/BYOC and support. See langchain.com/pricing for current tiers.
What is LangSmith? LangSmith is a coding tool listed on Scriptiii AI Tools. LangChain platform for tracing, monitoring and evaluating LLM applications and agents. Pricing: Freemium. Free tier with paid upgrades. Best for: ai-agents, tool, observability-evals.
Questions & answers
Everything you need to know about LangSmith
What is LangSmith?
LangSmith is a coding tool. LangChain platform for tracing, monitoring and evaluating LLM applications and agents.
What does LangSmith cost?
Freemium. Free tier with paid upgrades.
What is LangSmith best for?
ai-agents, tool, observability-evals. It is filed under Coding.
