x-common-marker-version
`x-common-marker-version` appears on header objects. Its value is a structured object. Used by 2 providers across 14 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
HTTP header, not an extension
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.
This is an HTTP header name, not a vendor extension. It appears
under a
headers: map, which is the same syntactic position an extension
key occupies — but OpenAPI models headers natively and this is not extending
anything. It is listed here because it turns up when you inventory the
x- namespace, and leaving it out would hide why the namespace looks
bigger than it is.
14 occurrences
14 documents
2 providers
purpose-named
Where it appears
| Location in the document | Occurrences | |
|---|---|---|
| header | 14 |
What its value looks like
| Value shape | Occurrences |
|---|---|
| object | 14 |
Providers publishing it
All 2.
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.