Mutation path names a bid the response does not contain
The seat and bid id in the path do not resolve to a bid in the carried bid response.
What it means
The path is a bid reference, /seatbid/{seat}/bid/{bid id}, and no seatbid with that seat holds a bid with that id.
Why it matters
Bid shading names its target by seat and bid id rather than by position, so a mismatch is not recoverable by looking nearby. A shading proposal that cannot be resolved is a price that silently does not change.
How to fix it
Read the seat and bid id out of the bid response in this envelope. Watch for shading a bid from a different seat than the one it belongs to.
Example that trips it
{ "intent": "BID_SHADE", "op": "OPERATION_REPLACE", "path": "/seatbid/dsp-9/bid/bid-abc", "adjust_bid": { "price": 3.15 } }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.