Trace and Debug LLM Apps

Why tracing

LLM apps are non-deterministic and multi-step. When something's wrong, you need to see the exact prompts, retrieved context, tool calls, and responses.

What to capture

• The full prompt and final response.
• Retrieved chunks and their scores (for RAG).
• Tool calls and their results (for agents).
• Latency and token counts per step.

Tooling

Tools like LangSmith, Helicone, or Langfuse capture this with minimal setup. Even a structured log to your database beats flying blind. Add tracing before you need it — debugging without it is miserable.