Data & schema semantics · Type system

x-ms-discriminator-value

`x-ms-discriminator-value` appears on schema objects and properties. Its value is a string. Used by 4 providers across 198 OpenAPI documents. It sits in the `x-ms-` namespace, so its meaning is defined by ms tooling rather than by OpenAPI. Observed values include `A2A`, `#microsoft.graph.user`, `InMageRcm`, `#microsoft.graph.group`. Consistent with type system — this is inferred from where the key appears and what it carries, not from any published definition.

Data & schema semantics x-ms- 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.
4051 occurrences
198 documents
4 providers
vendor-named

Where it appears

Location in the documentOccurrences
schema 4051

What its value looks like

Value shapeOccurrences
string4049
object2

Observed values

Sampled from the specifications, most frequent first.

A2A#microsoft.graph.userInMageRcm#microsoft.graph.groupInMageAzureV2VMwareCbtHyperVReplicaAzureStateful

Providers publishing it

All 4.

affindaengineering-platformmicrosoft-azuremicrosoft-graph

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.