Features

Llm Tracing

Trace LLM calls, tool invocations, and agent reasoning steps end-to-end

Cost Tracking

Track token usage and cost per request, per agent run, and per model

Evaluation

Score agent outputs against test datasets with automated evaluators

Prompt Management

Version, manage, and A/B test prompts in production

Real Time Monitoring

Live dashboards and alerting for agent performance metrics

LangSmith

LangSmith is LangChain's proprietary observability and evaluation platform. If you're building agents with LangChain or LangGraph, LangSmith provides the deepest tracing integration available — every chain step, tool call, and LLM invocation is captured automatically.

The evaluation suite lets you build test datasets, run agents against them, and score outputs with custom or LLM-based evaluators. The tradeoff is tight coupling to the LangChain ecosystem — if you move away from LangChain, LangSmith becomes significantly less useful.

LangSmith

Best for

Limitations

Features

Frameworks

SDK Languages

Compliance

LangSmith