Data & schema semantics

x-url-content-negotiation-extensions

`x-url-content-negotiation-extensions` appears on response objects. Its value is a structured object. Used by 2 providers across 2 OpenAPI documents. Consistent with data & schema semantics — this is inferred from where the key appears and what it carries, not from any published definition.

Data & schema semantics derived description
How this description was produced. It is assembled from what was measured in the corpus — where this key appears in a document, what shape its value takes, the values observed, and how many providers use it. It is not taken from a published definition, because for most extensions none exists. Read it as evidence, not as a specification. If you own this extension and want it described properly, tell us.
4 occurrences
2 documents
2 providers
purpose-named

Where it appears

Location in the documentOccurrences
response 4

What its value looks like

Value shapeOccurrences
object4

Providers publishing it

All 2.

noaaweather-gov

Why this is not in OpenAPI

Extensions exist because a provider needed something the specification would not carry. Most of what they hold is not the API contract at all — it is operational metadata about the contract: documentation, lifecycle, policy, provenance, and now agents. That metadata is usually better placed alongside the contract, in an Overlay or an APIs.json index, than crammed inside it. See everything else doing the data & schema semantics job.