The README's OIDC section is written against Authentik and stays that
way; Entra differs enough that inlining it would have doubled a file
that is already 32k. The new doc parallels the README's A/B structure so
the two are diffable, and leads with the traps, since every one of them
surfaces as an opaque 401 rather than as anything resembling its cause:
the access token version, the tenant-specific authority, `aud` being the
client-ID GUID while the requested scope is an `api://` URI, redirect-URI
platform types, and group GUIDs.
Sections 7 and 10b document the identity and overage behaviour shipped
in the previous commit, including the one upgrade-ordering caveat: an
existing Entra deployment should sign a user into the Web UI once before
reconnecting their MCP client, or the pre-migration row is stranded.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Three defects stood between this codebase and a working Entra deployment.
All three fail silently, which is why they are grouped: each one masks the
next, and fixing any two still leaves a broken or dangerous install.
1. JWKS discovery. The key set URL was hardcoded to `${issuer}/jwks/`,
which is Authentik's convention, not a standard. Entra serves keys at
`/{tenant}/discovery/v2.0/keys`, so every Entra-issued MCP token failed
verification on a 404 — authentication was impossible, not merely
misconfigured. We now read `jwks_uri` from the issuer's discovery
document and fall back to the old path, so Authentik is untouched.
Discovery failure arms a 60s retry rather than pinning the wrong URL
for the life of the container.
2. Identity. Entra's `sub` is pairwise — derived from the token
recipient — so the Web UI and MCP app registrations emit different
`sub` values for the same human. Keyed on (iss, sub), that person got
two rows: sign into the Web UI, connect Claude Code, land in an empty
account. Both paths upsert, so nothing errored. Identity now keys on
`oid`, which Microsoft documents as constant across applications in a
tenant, via one resolver both surfaces share. Rows created before the
0005 migration adopt their `oid` on next sign-in.
3. Groups overage. Past 200 groups Entra omits `groups` entirely and
substitutes a `_claim_names` pointer. `normalizeGroupsClaim` read that
as "zero groups" and the sync deleted every membership the user had,
revoking access to every shared project on both surfaces with no error
raised. Both surfaces now refuse such a token instead — the Web UI
fails the sign-in, MCP returns 401 — leaving memberships intact and
naming the operator fix. An absent claim with no overage marker still
clears memberships, which is unchanged and deliberate.
Verified against a real pgvector instance: 66 tests pass, and reverting
either new behaviour fails exactly the tests that cover it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
shadowdaoandClaude Opus 5