LangChain Agent

File: examples/langchain_agent.py

Demonstrates the LangChain integration. Attaches TraceAgentLangChainCallback to a LangChain agent so chain steps, LLM calls, tool usage, and retriever activity are traced automatically.

Run

uv run examples/langchain_agent.py

Environment Variables

This example expects an OpenAI-compatible endpoint such as LM Studio:

Variable	Description
TRACE_AGENT_BASE_URL	TraceAgent server URL
OPENAI_BASE_URL	OpenAI-compatible endpoint
OPENAI_API_KEY	API key for the model provider

What It Does

1. Initializes the TraceAgent client and starts a run
2. Creates a LangChain agent with tools
3. Attaches TraceAgentLangChainCallback as a callback
4. Executes the agent — all steps are traced automatically
5. Finishes the run