The Financial-grade API working group's pushed request object specification is deprecated and no longer maintained.
The FAPI working group suggest that implementers use OAuth 2.0 Pushed Authorization Requests ('PAR'), which have been standardised at the IETF OAuth working group:
https://datatracker.ietf.org/doc/html/rfc9126
For historical reference, the FAPI WG's final version of this specification can be viewed here:
To view the FAPI working group's current documents see: