Data & schema semantics · Naming & aliasing

x-additionalPropertiesName

`x-additionalPropertiesName` appears on schema objects and properties. Its value is a string. Used by 12 providers across 12 OpenAPI documents. Observed values include `locationId`, `fieldApiName`, `space-name`, `field tag`. Consistent with naming & aliasing — 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.
114 occurrences
12 documents
12 providers
purpose-named

Where it appears

Location in the documentOccurrences
schema 111
parameter 2
response 1

What its value looks like

Value shapeOccurrences
string114

Observed values

Sampled from the specifications, most frequent first.

locationIdfieldApiNamespace-namefield tagmenuIdproperty-identifieraggregate-idcontainerPropertyIdentifier

Providers publishing it

All 12.

cogniteemailoctopusfdc3garner-healthlawvulichesslightspeed-posmongodbotterpeertubesentinel-hubvery-good-security

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.