Chapter 6: Callback and Trace (observability)

Goal of this chapter: understand the Callback mechanism and integrate tracing/observability for the Agent execution.

Code location

• Entry code: cmd/ch06/main.go

Full tutorial

• ch06_callback.md

What you learn

• How callbacks expose lifecycle hooks for key execution points (model calls, tool calls, streaming chunks).
• How to build logging/metrics/tracing without coupling instrumentation into core logic.