The response proposes no mutations
The agent returned an empty mutation set, so the orchestrator paid for the call and has nothing to evaluate.
What it means
The response carries no mutations, either because the field is absent or because it is an empty array.
Why it matters
An empty answer is legitimate: an agent that has nothing useful to propose should say so rather than invent something. It is worth a warning because a persistently empty agent is indistinguishable from a broken one, and the in-auction call is not free.
How to fix it
Nothing to fix in the payload. If the emptiness is unexpected, check whether applicable_intents excluded everything the agent knows how to do.
Example that trips it
{ "id": "ep-1", "mutations": [], "metadata": { "api_version": "1.0.0", "model_version": "curation-2026.07" } }Check your payload
Paste a bid request or response into the tester to see whether this code fires against it, or gate on the id in CI with the CLI: the id is stable, wording is not.
Back to the full diagnostic code reference.