# `workflows/trail` Source: [`src/workflows/trail.ts`](https://github.com/AI-for-dev/combo/blob/main/src/workflows/trail.ts) The trail: every result a workflow produced so far, over its own clock. What a workflow reports besides its answer - the steps it took, what they cost over the time the whole thing took, and the first step that failed - used to be kept by each combinator in its own variables, with its own `performance.now()` and its own sum. The pool records into a trail as it plays turns, so a combinator reads the envelope instead of keeping one. ## `Trail` *class* ```typescript export class Trail { readonly steps: Result[] = []; record(result: T): T { /* … */ } usage(): Usage { /* … */ } broken(): Result | undefined { /* … */ } } ``` The results a workflow produced, in order, and what they add up to.