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LangSmith

Framework-agnostic tracing, evaluation, and monitoring for agents

LangSmith traces and evaluates AI agents across LangChain, OpenAI, Anthropic, Vercel AI SDK, LlamaIndex, and custom stacks. It captures model and tool trajectories, latency and cost, supports online and offline evaluations, clusters failure patterns, and can alert teams when production quality regresses.

Best for agent capabilities

Useful in agent tasks

Overview

Authapi key
PricingFree tier available · $0 with 5,000 base traces/month
SDKspython, typescript, go, java
OpenAPINo
MCP SupportNo

When to use LangSmith

LangSmith is listed for Observability, Monitoring workflows. LangSmith traces and evaluates AI agents across LangChain, OpenAI, Anthropic, Vercel AI SDK, LlamaIndex, and custom stacks. It captures model and tool trajectories, latency and cost, supports online and offline evaluations, clusters failure patterns, and can alert teams when production quality regresses. Consider it when an agent needs this capability through a documented service boundary instead of custom infrastructure maintained inside the application.

In 4agent's task model, the product maps to observability and evaluation. That makes it a candidate for workflows that research the web, build and deploy software, manage memory and knowledge, automate business workflows.

Integration checklist

  • Access: confirm the api key authentication flow, credential scope, rotation process, and whether calls can be attributed to a user or service identity.
  • Client support: official or documented clients are listed for python, typescript, go, java.
  • Automation: OpenAPI is not currently recorded, MCP is not currently recorded, and CLI support is not currently recorded. Confirm each requirement in the provider's current documentation.
  • Operations: test rate limits, timeouts, retry safety, error payloads, logs, data retention, and the current free-tier and paid pricing model with production-like volume.

Sources and verification

Use these primary sources to verify current behavior before making an implementation or purchasing decision. Product capabilities, limits, and prices can change after a 4agent listing is reviewed.