The first-party client signs in on /clientapi and exchanges that JWT on
/oauth/token (RFC 8693, subject_token_type jwt, avatar_id) for one
persona's Mastodon token. Only the seeded public application `decepub`
holds the grant; RootJwtSubjectToken validates the JWT through RootJwt,
which JwtBearer now shares (signature, lifetime, ban, deletion, session
stamp). The issued token names the avatar, never the root.
Owner decision recorded in ROADMAP; it supersedes "moving decePubClient
onto the Mastodon API is out of scope".
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw
OpenIddict 7.7 (MongoDB stores, keys kept in Mongo so tokens survive
restarts) serves /oauth/authorize, /oauth/token, /oauth/revoke and the
discovery documents, including /.well-known/oauth-authorization-server:
- authorization code (PKCE optional) and client credentials, Mastodon's
scopes including the granular ones, non-expiring reference tokens,
`created_at` in the token response, and the urn:ietf:wg:oauth:2.0:oob
page that shows the code;
- /oauth/login signs the private login into a fifteen-minute cookie that
only /oauth sees (rate limited, antiforgery-protected); /oauth/authorize
then asks which persona the application acts as. The token's subject
is that persona's id and nothing else; no root id reaches a token, an
authorization or a log line;
- the token exchange refuses a persona whose login is banned or deleted,
and every API request checks the same.
/api/v1/apps registers applications dynamically, /api/v1/apps/
verify_credentials, /api/v1/instance (v1 and v2, "4.2.0 (compatible;
PrivaPub)") and verify_credentials answer in Mastodon's shapes: snake_case
with explicit nulls, Rails-style parameters from query, form or JSON,
{"error": ...} on failure, Link paging. CORS exposes Link.
/api goes to OpenIddict validation and everything else to the existing
JWT; the JWT failure handler no longer sends the exception and stack trace
to the client.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB