AsyncAPI breaking changes¶

AsyncAPI 2.x and 3.x: channels, messages and payload schemas, with diffing that knows which direction a channel runs. A payload field removed from a message you publish breaks your subscribers; one removed from a message you subscribe to breaks you.

apiverity breaking events-v1.yaml events-v2.yaml

The 18 catalogued rules observed firing on asyncapi¶

Measured, not asserted: this format's own shipped fixture is perturbed in each of several dozen ways and the result is whatever the rules said. A rule listed here was seen firing on this protocol in this build; one that is absent was not, which may mean the rule does not apply or that no mutation reached it.

Rule	Severity	What it means
`BRK-CONSTRAINT-TIGHTENED`	ERROR	A request constraint was tightened; previously valid inputs fail.
`BRK-DEPENDENT-REQUIRED-ADDED`	ERROR	Sending one field now requires another. A request that set the first without the second was valid and is not.
`BRK-DEPRECATION-ADDED`	WARN	The operation is now deprecated; plan migration.
`BRK-ENUM-NARROWED-REQUEST`	ERROR	Request enum values were removed; clients sending old values fail.
`BRK-ENUM-WIDENED`	INFO	Enum values were added (additive).
`BRK-PARAM-ADDED-OPTIONAL`	INFO	A new optional request parameter was added.
`BRK-PARAM-ADDED-REQUIRED`	ERROR	A new required request parameter was added.
`BRK-REQ-BODY-ADDED-OPTIONAL`	INFO	An optional request body was added.
`BRK-REQ-BODY-REMOVED`	ERROR	The request body was removed.
`BRK-REQ-FIELD-ADDED-OPTIONAL`	INFO	An optional field was added to a request body.
`BRK-REQ-FIELD-ADDED-REQUIRED`	ERROR	A required field was added to a request body.
`BRK-REQ-FIELD-BECAME-REQUIRED`	ERROR	A request body field became required.
`BRK-REQ-FIELD-OPTIONALIZED`	INFO	A request body field became optional; senders are unaffected.
`BRK-REQ-FIELD-REMOVED`	ERROR	A request body field was removed.
`BRK-RPC-REMOVED`	ERROR	A gRPC RPC was removed; existing callers will fail.
`BRK-SECURITY-CHANGED`	ERROR	Security requirements changed; unprepared clients fail auth.
`COMPAT-MEDIA-ADDED`	INFO	An operation gained a media type.
`COMPAT-MEDIA-REMOVED`	WARN	An operation dropped a media type it used to accept or return.

The full catalogue has the rationale and the remediation for each. Rule parity is the same measurement across every format at once.

The rest of the toolchain speaks this format too¶

One contract model means the other commands are not separate tools:

apiverity validate contract          # lint and security checks
apiverity changelog old new          # a human changelog of the same diff
apiverity coverage contract          # which operations your tests reach
apiverity drift contract --base-url  # does the running service still match?

Protocol support is the full matrix of what each format supports, and what it does not.