Identity Model

Identity model

MID <-> PID
REF -> storage -> MID

The MID is the source of truth. Its PID carries exactly the same 128 UUID bits with a registered TypeID prefix.

A REF does not encode the MID. Applications maintain the REF-to-MID relationship in storage and must cross an atomic allocation boundary before claiming a REF is unique.

Human-reference strategies

Random references use a cryptographically secure Crockford Base32 payload, canonical grouping, and a modulo-37 check symbol. Atomic unique insertion with bounded retry establishes allocation.

Sequential references use a fixed-width decimal sequence with an optional UTC calendar-year scope. A transactional allocator must advance the counter and bind the sequence to the supplied MID in the same transaction.

See the normative specification for the complete contract.