openrtb.field.undefined

What it means

The field does not exist in the OpenRTB catalog for the version you validated against. It is usually a typo (bidflor, tagId), a field invented in-house that belongs under ext, or a field from a different object pasted at the wrong level. Subtrees under ext are intentionally left open and never trip this code.

Why it matters

OpenRTB tells consumers to ignore unknown fields, so nothing errors: the data you meant to send simply never arrives. A misspelled field carrying a floor, a consent signal, or a deal id fails silently, which is far more expensive than a loud rejection.

How to fix it

Fix the spelling to the canonical field name, or move proprietary data under the nearest ext object, which is the spec's designated extension point. The finding's path shows exactly which key was not recognized.

Example that trips it

{ "imp": [{ "id": "1", "bidflor": 2.5 }] }

A misspelled bidfloor is ignored by every consumer, and the floor never applies.

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.