request-body-discriminator-added

What this check detects

A discriminator is a hint on a oneOf / anyOf schema that tells a consumer which of the listed subschemas a payload conforms to, by reading a named property (propertyName) rather than trying each subschema in turn. It is used mainly by code generators and validators to map a value to a concrete type.

Adding a discriminator changes how the request body is interpreted: the named property must now be present and must match one of the mapped subschemas. oasdiff reports it as informational, but review it, because a payload that validated against a branch by structure alone may now be routed by the discriminator value instead.

Example

A discriminator now selects which subschema the request body is validated against, based on the "petType" property.

Change its severity

oasdiff reports request-body-discriminator-added as informational, so it does not fail CI. To treat it as a warning or an error under your own compatibility policy, or to turn it off, set its level in a severity-levels file:

Put one rule per line; the level can be err, warn, or info, or none to disable the check entirely:

# severity.txt
request-body-discriminator-added err

Then pass it to oasdiff:

oasdiff changelog base.yaml revision.yaml --severity-levels severity.txt