AI Letters #27 - Agent Observability: 3 Lines Gets You In, But What Can You Actually See?
"Three lines to enable tracing in LangChain. Zero lines of latency data when you're done."
Every agent fails eventually. A tool returns nothing. The LLM loops on the same thought. The retrieved documents are all wrong. What separates a two-minute debug from a two-hour one is not how the agent was built - it's how much you can see when it breaks.
Notebook #19 of the LLM Showdown measured one thing: how much can you observe about a running agent without leaving your local environment? No external service. No API key for a tracing platform. No paid tier. Just framework-native observability on the same machine where your code runs.
LangChain enables tracing in the fewest lines. What those lines actually surface is a different question.
