Account
Not available yet. This page says what is planned, not what you can call today: there is no route for it in the API reference, and the platform follows its measured velocity rather than a calendar.
Planned. One-time codes, sessions and multi-factor authentication, with one user directory per project, never shared between products.
What you can do today. Build against the parts that already exist, because they are the ones Account will use: authentication, idempotency, webhooks, the sandbox conventions and the error contract.
When Account ships it will arrive with its own guide here, its routes in the reference, its deterministic sandbox scenarios, and its place in the erasure call.