Command grants

A command grant is a signed authorisation from you to a service centre to perform a specific set of actions on your vehicle, for a specific time, under a specific tier.

Each grant carries:

• A scope list (e.g. acceptHandoff, performScope:park, performScope:returnToOwner).
• A tier that names the autonomy regulation it operates under.
• A TTL — the grant expires automatically.
• A signature chain verified against the OEM's public keys, hashed with SHA-256, and witnessed by VSBS, the OEM, and the geofence operator.

The canonical bytes use RFC 8785 (JSON Canonicalisation Scheme) so that the signature is deterministic across implementations.