Test
LangSmith’s testing tools help you measure agent quality, iterate on prompts, and debug live in an interactive environment.Get started
Create an account
Sign up at smith.langchain.com (no credit card required).
You can log in with Google, GitHub, or email.
Create an API key
Go to your Settings page → API Keys → Create API Key.
Copy the key and save it securely.
Choose your integration
LangSmith works with many frameworks and providers. Browse available integrations to connect your stack.
Explore testing tools
Evaluation
Create datasets, define evaluators, and run experiments to measure agent quality over time.
Prompt engineering
Author, version, and collaborate on prompts in the Prompt Hub and playground.
Context Hub
Manage versioned instructions and tools your agents use, and promote them across environments.
Studio
Use an interactive environment for developing and debugging agents.
Find and fix failures with Engine
When evaluations surface failures, use LangSmith Engine to diagnose the root cause and resolve them.
Connect these docs to Claude, VSCode, and more via MCP for real-time answers.