Ledger API supports multi-party reads, JSON API does not.
JSON API authentication/authorization was designed a bit a head of Ledger API and we did not have a use case for multi-party reads in JSON API.
Our take on multi-party authentication in JSON API:
- 1 party - 1 authentication token (JWT), no super users
- if participant needs to act as multi-party, this participant needs multiple authentication tokens (one per party)