oauth context (v2)

Placeholder for the v2 oauth context — v2 is unreleased and defines no endpoints here.

The v2 oauth context is not defined yet. This is a placeholder listing what will live here once v2 ships.

Planned content

Content	Notes
Endpoint groups	Whether the token, keys, authorization and grants groups are kept
Differences from v1	Changes to protocol shapes or authentication, listed one by one
Audience	Whether `{issuer}` and the `oauth` audience stay the same in v2