Backward compatibility

indexnowkit/doctrine follows SemVer. Before 1.0, minor versions may contain breaking changes; every one is listed under "Changed" in CHANGELOG.md with the migration. After 1.0 the rules below become the promise. The core's tiers ("call", "implement", "may grow") apply to every core class you touch through this package: core bc.md.

What the package keeps stable

Surface	Promise
IndexNowDoctrine (registerMiddleware(), registerListener(), the constructor's named parameters)	Method and parameter names stay; new parameters are appended with defaults.
IndexNowListener (the onFlush / postFlush subscriber) and Middleware\IndexNowMiddleware	Their constructors' named parameters and the Doctrine events they subscribe to stay. They are final: put your own logic on top of the core ObjectChangeHandler, not on a subclass.
Behaviour described in the README: URLs resolved in onFlush while the old state is live, handed over only after the outermost transaction committed, nothing on rollback, deletions resolved before the row disappears, savepoints honoured	A change to any of these is a breaking change and appears in the changelog with the conformance ids (A01–A21) it affects.
DBAL 3 and 4, ORM 2.19+ and 3	Dropping a major of either is a breaking change of this package.

Not a contract: Middleware\IndexNowDriver, Middleware\IndexNowConnection, Middleware\IndexNowConnectionV3, Middleware\SavepointStatement (the DBAL wrapping, which follows DBAL's own API), and log message texts (their context keys are).

Pinning

composer require indexnowkit/doctrine:^0.5 gets every 0.5.x patch. Read the changelog before a minor.