Runtime & gateway

x-google-backend

`x-google-backend` appears on operations. Its value is a structured object. Used by 2 providers across 2 OpenAPI documents. It sits in the `x-google-` namespace, so its meaning is defined by google tooling rather than by OpenAPI. Consistent with runtime & gateway — this is inferred from where the key appears and what it carries, not from any published definition.

Runtime & gateway x-google- namespace 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.
21 occurrences
2 documents
2 providers
vendor-named

Where it appears

Location in the documentOccurrences
root 1
operation 20

What its value looks like

Value shapeOccurrences
object21

Providers publishing it

All 2.

clevergydoppel

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 runtime & gateway job.