Module 04 · Agent

Agent frameworks

What a framework adds to the loop you already wrote, built rather than described. A registry that derives schemas, five hook points and a trace, and an agent expressed as data you can validate and diff.

4 lessons · 3 graded exercises·4 hours·intermediate·Prerequisite: Tool use and building an agent

What frameworks abstract

25 min

You already wrote the engine. A framework adds five things around it, in one of two shapes, and charges you in stack traces and in coupling. Knowing which five is what makes the choice a decision.

Build a mini framework

50 min · exercise

A schema derived from a signature, a registry that is the single definition of a tool, and an agent object that owns the loop. The smallest thing that deserves the name.

Middleware and tracing

40 min · exercise

Five places where something else can listen, held in a list rather than a class hierarchy, and one listener that writes a record per step. Everything a framework calls observability is those two ideas.

When to adopt one

35 min · exercise

An agent written as data can be inspected, diffed and generated, and stops dead the moment you need behaviour the schema cannot express. Then four questions that make adoption a decision rather than a mood.