LangSmith - LLM Observability Platform

Development platform for debugging, evaluating, and monitoring language models and AI applications.

When to use LangSmith

Use LangSmith when:

• Debugging LLM application issues (prompts, chains, agents)
• Evaluating model outputs systematically against datasets
• Monitoring production LLM systems
• Building regression testing for AI features
• Analyzing latency, token usage, and costs
• Collaborating on prompt engineering

Key features:

• Tracing: Capture inputs, outputs, latency for all LLM calls
• Evaluation: Systematic testing with built-in and custom evaluators
• Datasets: Create test sets from production traces or manually
• Monitoring: Track metrics, errors, and costs in production