What the assistant did

Larkspur’s assistant is live. Customers ask it about orders and policies all day, and the team has passed Evals’ offline suite. Now they want to know what it does with real traffic.

This chapter: What happened, step by step, when a customer asked the assistant a question?

You will learn

A trace: one request’s record, from the question to the reply
Spans: the steps inside it (retrieval, model calls, tool calls, the reply)
Reading a trace as a waterfall: what ran, in what order, for how long

Words you’ll meet (3)

Trace: The record of one request through the assistant, made of spans.
Span: One step in a trace, with a start, an end and what it did. Spans nest: the whole run is the parent of its steps.
Waterfall: A trace drawn as one row per span, each bar placed where the step started and as long as it took.

The picture on the left is live. Each step below asks you to do one thing in it; the story continues here as you go.

Step 1 of 4

Larkspur’s assistant answered 40 customer questions yesterday, and each left a trace: the record of one request, from the question to the reply. The wall in the picture holds them all. Open the first.