EvalIs the pipeline stable?
Model swap
The same cluster twice with one agent on a different model. Is the cheaper model faithful to the stronger one, and at what price?
Two arms
Arm A is the reference, normally the production models. Arm B is identical except for --swap=<agent>:<model>. The report is the agreement on every axis, with each arm’s metered cost beside it.
The allocator decides which model works on which claim, and today that rests on a guess. Where a cheap model agrees with the strong one it is safe to save money; where it does not is where not to.
Detail
What it cannot show
That the strong model is right. Fidelity is relative: where both are wrong together, it reads as agreement.
Run it
npm run corpus:swap -- eggs --agent=steward --model=claude-sonnet-5 --profile=production --baseline=<snapshot>
npm run corpus:swap -- lableak --agent=matcher --model=claude-haiku-4-5-20251001 --profile=production