# Compatibility

Document revision **2.0.0** is an intentional breaking reset of the earlier staging `/v1`
contract: run and approval paths, resource identities and response types changed together.
Existing integrations must update their requests and generated types. This reset is an
explicit exception to the previous six-month notice promise; no prior notice or external
client migration is claimed. The complete change record is `docs/api-reset-2.md` in the
repository. The policy below applies to subsequent changes.

Response objects are open: new fields can ship within `/v1`, and clients should ignore fields
they do not recognize. Send only documented request keys; request bodies are strict.

Enums are closed. Adding an enum value is a breaking change because generated clients validate
against the published union. New values must use a new field or operation rather than extending
a published enum in place. Treat an unknown enum value as a client/schema mismatch. Event
discriminators are also defined by the published schema; do not assume they can expand silently.

Breaking changes require `/v2`, with `Deprecation` and `Sunset` headers on `/v1` at least six
months before removal. Follow the generated reference for the deployed schema.

Send `X-Request-Id` with 8–64 characters from `[A-Za-z0-9._-]` for correlation. The response
echoes the id it used; include it when reporting a problem. See [Errors](/errors) for the format
and reason catalog.