infrastructure

LangSmith

by LangChain

LangSmith is LangChain's full-stack LLMOps observability and evaluation platform, purpose-built for debugging, monitoring, and testing LLM applications and agents. It provides end-to-end tracing of every LLM call, tool invocation, and chain step alongside automated and human-in-the-loop evaluation workflows. While deeply integrated with LangChain and LangGraph, it supports any LLM provider via SDKs for Python, TypeScript, Go, and Java, plus OpenTelemetry compatibility.

8 Overall Score

Scores

Capability
8
Ease of Use
7
Documentation
8
Reliability
8
Value
7
Momentum
8

Details

Status
active
Pricing
freemium
Launch Date
2023-07
Last Updated
2026-03-15

Key Features

  • Full LLM trace capture with nested span visualization for chains, agents, and tool calls
  • Automated and human evaluation frameworks with multi-turn and trajectory scoring
  • Prompt management, versioning, and A/B testing across model providers
  • Production monitoring with latency, cost, and error dashboards
  • Dataset management for regression testing and continuous evaluation pipelines

Tech Stack

PythonTypeScriptGoJavaOpenTelemetryPostgreSQLReact