Data & schema semantics · Size & shape

x-field-extra-annotation

`x-field-extra-annotation` appears on schema objects and properties. Its value is a string. Used by 10 providers across 35 OpenAPI documents. Observed values include `@com.fasterxml.jackson.annotation.JsonInclude(com.fasterxml.jackson.annotation.J`, `@com.redis.om.spring.annotations.Indexed`, `@jakarta.validation.constraints.PastOrPresent`, `@lombok.ToString.Exclude`. Consistent with size & shape — 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.
325 occurrences
35 documents
10 providers
purpose-named

Where it appears

Location in the documentOccurrences
schema 283
tag 2
operation 40

What its value looks like

Value shapeOccurrences
string311
array14

Observed values

Sampled from the specifications, most frequent first.

@com.fasterxml.jackson.annotation.JsonInclude(com.fasterxml.jackson.annotation.J@com.redis.om.spring.annotations.Indexed@jakarta.validation.constraints.PastOrPresent@lombok.ToString.Exclude@com.fasterxml.jackson.annotation.JsonFormat(pattern = "yyyy-MM-dd''T''HH:mm:ss"@jakarta.validation.constraints.NotBlank@Valid@NotBlank

Providers publishing it

All 10.

cosmo-techfoliofundrisehmctslean-technologiesleaplightspeedobservepointpagopatui-group

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.