No. Ory Kratos generates the identity ID (UUID) and it cannot be chosen or changed. When creating or importing identities, you can set traits and optional fields like external_id, but not the primary id. For migrations/restores, use external_id to preserve your own identifier and look up the generated id via the “get by external_id” API (the identity id “can not be changed and can not be chosen”; use external_id for migration and lookups) ([Identity model](https://www.ory.sh/docs/kratos/manage-identities/overview)), ([External Identifiers](https://www.ory.sh/docs/kratos/manage-identities/external-id)).

Yes. When creating or updating an OAuth2 client via the Admin API, you can set the client’s ID explicitly. The create endpoint echoes the provided client_secret (or generates one if omitted), and the set (PUT) endpoint replaces a client by its ID, allowing you to choose the ID path parameter and update all fields (be careful: it replaces the entire client) ([createOAuth2Client](https://raw.githubusercontent.com/ory/hydra/master/spec/api.json), [setOAuth2Client](https://raw.githubusercontent.com/ory/hydra/master/spec/api.json)). Using Ory tooling: - Ory Network/CLI supports creating and updating clients; the “update” commands replace the whole client, mirroring the PUT semantics (useful if you need to enforce a specific ID you control via API) ([Manage OAuth2 clients](https://www.ory.sh/docs/hydra/guides/oauth2-clients), [ory update oauth2-client](https://www.ory.sh/docs/cli/ory-update-oauth2-client#ory-update-oauth2-client), [hydra update oauth2-client](https://www.ory.sh/docs/hydra/cli/hydra-update-oauth2-client#hydra-update-oauth2-client)).