UUIDv7 Ecto type used for all primary and foreign keys.
UUIDv7 embeds a 48-bit unix-millisecond timestamp in the most significant bits, so freshly inserted rows sort (and index) in insertion order like the old integer ids did, while remaining unguessable — random ids prevent enumeration of API resources.
Cast/dump/load are delegated to Ecto.UUID, so storage behavior matches
:binary_id on both SQLite and Postgres; only generation differs (v7
instead of v4).
Summary
Functions
Casts a value to a UUID string, returning nil when invalid.
Generates a UUIDv7 string (time-ordered, RFC 9562).
Functions
@spec cast_or_nil(term()) :: Ecto.UUID.t() | nil
Casts a value to a UUID string, returning nil when invalid.
Convenience for boundary code (channel topics, URL params) that previously
used Integer.parse/1 to validate ids.
@spec generate() :: Ecto.UUID.t()
Generates a UUIDv7 string (time-ordered, RFC 9562).
Uses the 12 rand_a bits as a per-millisecond sequence counter (RFC 9562
§6.2 method 1) so ids generated on the same node within one millisecond
still sort in generation order — code that orders by id (chat cursors,
pagination) keeps working under bursts.