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Patrick Buckley 8605c9783d feat(models): rfc8693_obo auth mode, per-alias exchange scopes, identity-keyed mint cache
Adds the dedicated `rfc8693_obo` model auth mode (#955): model
definitions gain an `obo_scopes` column (migration 069), the mint
threads the scopes to the token-exchange leg (RFC 8693), and every
dynamic mode pins its grant leg — a mode is a dialect commitment, not a
hint the deployment profile resolves. Exchange-capable IdPs refuse an
audience whose scope was not requested; this closes the structurally
unmintable model-OBO path on token-exchange deployments.

The model mint-cache is identity-keyed on the owning definition's
alias (`__model_obo__:<alias>` per user, `__model_app__:<alias>` under
the shared app principal), matching the MCP discipline where rows key
on the unique server name. The bearer's shape lives in the row's
audience/scopes columns and the freshness gate compares it on every
read, so a re-aimed alias refuses its old row and overwrites the same
key in place. Admin lifecycle (rename, re-aim, scope change, delete)
purges a definition's own rows through one shared helper — sound
because one definition owns each key; a sibling's rows are untouchable
by construction. Cooldown and backoff additionally key on the dispatch
shape, so an operator's config repair is an instant clean slate. Cause
records, cooldowns, locks and memoization are per-alias end to end,
and the session heartbeat reads refusal causes under the same keys.

Console: default-deny write gating for dynamic rows (value-diff over
the full column ladder, admin.mcp escalation, a never-blockable
pure-disable carve-out), a two-tier validator (audience allow-list on
every write; deployment-posture checks when the pair is chosen), one
shared scopes parser whose omit-unchanged arm keeps over-cap DB-direct
residue rows disarmable without ungating real changes, and served
constraints (dynamic/scopes/app-identity mode lists, mode-to-profile
pairing) so the shelf tracks the registry by data. The admin shelf
gains the mode option, a scopes input with residue affordances,
pairing-aware option greying, and a derived auth badge.

Registry load refuses control characters in alias, audience, and
scopes — including the C0 separator block that str.split() would
silently collapse — and the C0/DEL class has one exported spelling
shared by every surface. Profile-mismatch visibility warns at reload
and boot with the mode-correct cause, gated on OIDC being enabled.

Breaking: a stored `entra_obo` alias on a deployment whose
`[oidc] obo_grant_profile` is `rfc8693` (or the inverse pairing) no
longer mints via the profile-driven overload — the mint refuses before
any IdP traffic with cause `grant_profile_mismatch`, and the
`model.auth_fail_closed` policy governs static fallback. Such rows
never minted usefully on scope-gating IdPs; the shelf now surfaces the
pairing and the per-turn heartbeat names the refusal cause.

Live-verified end to end: scoped token exchange mints, the warm cache
serves with zero IdP calls, and the mode/profile mismatch refuses with
zero IdP traffic (scripts/obo-e2e/keycloak_e2e.sh); the
refresh-redemption profile's E1-E7 hold via scripts/obo-e2e/entra_e2e.py.

Closes #955.
2026-08-04 05:19:03 -07:00
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