diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index df70a84e..f85eca78 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -129,6 +129,18 @@ jobs:
       #     npm ci
       #     npm run build
 
+      # Generate an ephemeral Fernet key per CI run. docker-compose.yml
+      # requires TOKEN_ENCRYPTION_KEY (PR #758 finding 5 removed the
+      # hardcoded default), but the CI tokens.db is destroyed at the end of
+      # the job so there is no value in persisting the key as a repo secret.
+      # ``openssl rand -base64 32`` produces 32 bytes encoded as 44 base64
+      # chars; ``tr '+/' '-_'`` converts to URL-safe base64, which is
+      # exactly what Fernet expects.
+      - name: Generate ephemeral TOKEN_ENCRYPTION_KEY
+        run: |
+          KEY=$(openssl rand -base64 32 | tr '+/' '-_')
+          echo "TOKEN_ENCRYPTION_KEY=${KEY}" >> "$GITHUB_ENV"
+
       # Start services with the appropriate profile
       - name: Run docker compose
         uses: hoverkraft-tech/compose-action@4894d2492015c1774ee5a13a95b1072093087ec3 # v2.5.0
@@ -139,11 +151,8 @@ jobs:
         env:
           MCP_SERVER_URL: ${{ matrix.mcp-internal-url }}
           NEXTCLOUD_IMAGE: ${{ matrix.nextcloud_image }}
-          # Required by docker-compose.yml since PR #758 finding 5 (no more
-          # hardcoded Fernet keys). Generated once and stored as a repo
-          # secret; the CI tokens.db is ephemeral so a single shared key
-          # across services is acceptable.
-          TOKEN_ENCRYPTION_KEY: ${{ secrets.TOKEN_ENCRYPTION_KEY }}
+          # Inherited from $GITHUB_ENV via the previous step.
+          TOKEN_ENCRYPTION_KEY: ${{ env.TOKEN_ENCRYPTION_KEY }}
 
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@37802adc94f370d6bfd71619e3f0bf239e1f3b78 # v7.6.0
diff --git a/nextcloud_mcp_server/alembic/versions/20260502_1600_006_add_nonce_to_oauth_sessions.py b/nextcloud_mcp_server/alembic/versions/20260502_1600_006_add_nonce_to_oauth_sessions.py
new file mode 100644
index 00000000..8489e38f
--- /dev/null
+++ b/nextcloud_mcp_server/alembic/versions/20260502_1600_006_add_nonce_to_oauth_sessions.py
@@ -0,0 +1,29 @@
+"""Add nonce column to oauth_sessions for OIDC ID-token binding.
+
+PR #758 finding 2: the browser OAuth flow generated PKCE + state but no
+``nonce``. Without a nonce, an attacker who obtains a valid ID token for
+another user (e.g. from a parallel auth request) could replay it inside
+this flow because the token isn't cryptographically tied to the
+authorization request. The nonce is generated in ``oauth_login``,
+forwarded to the IdP in the auth URL, and verified on the way back.
+
+Revision ID: 006
+Revises: 005
+Create Date: 2026-05-02 16:00:00.000000
+"""
+
+from alembic import op
+
+revision = "006"
+down_revision = "005"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.execute("ALTER TABLE oauth_sessions ADD COLUMN nonce TEXT")
+
+
+def downgrade() -> None:
+    # SQLite < 3.35 cannot DROP COLUMN; leave the column on downgrade.
+    pass
diff --git a/nextcloud_mcp_server/auth/browser_oauth_routes.py b/nextcloud_mcp_server/auth/browser_oauth_routes.py
index 3d2c6186..cb0b33e9 100644
--- a/nextcloud_mcp_server/auth/browser_oauth_routes.py
+++ b/nextcloud_mcp_server/auth/browser_oauth_routes.py
@@ -19,6 +19,7 @@ from starlette.responses import HTMLResponse, JSONResponse, RedirectResponse
 
 from nextcloud_mcp_server.auth.token_utils import (
     IdTokenVerificationError,
+    get_oidc_discovery,
     verify_id_token,
 )
 from nextcloud_mcp_server.auth.userinfo_routes import (
@@ -65,7 +66,15 @@ def _origin_matches_self(request: Request, oauth_ctx: dict) -> bool:
     cfg = oauth_ctx.get("config") or oauth_ctx
     mcp_server_url = cfg.get("mcp_server_url")
     if not mcp_server_url:
-        # Mis-configured deployment — fail open rather than break logout.
+        # Mis-configured deployment — fail open rather than break logout, but
+        # log loudly so the operator can see this is happening (PR #758
+        # finding 3). Other OAuth code paths require ``mcp_server_url`` and
+        # KeyError if it's absent, so this branch should never fire in a
+        # correctly configured deployment.
+        logger.warning(
+            "CSRF check bypassed on /oauth/logout: mcp_server_url not "
+            "configured in oauth_context — set NEXTCLOUD_MCP_SERVER_URL"
+        )
         return True
 
     expected = _normalise_origin(mcp_server_url)
@@ -149,6 +158,12 @@ async def oauth_login(request: Request) -> RedirectResponse | JSONResponse:
     # Generate state for CSRF protection
     state = secrets.token_urlsafe(32)
 
+    # Generate OIDC nonce so the ID token returned on callback can be bound
+    # to THIS auth request (PR #758 finding 2). Without a nonce, an attacker
+    # who acquired a separate valid ID token could replay it inside this
+    # flow.
+    nonce = secrets.token_urlsafe(32)
+
     # Build OAuth authorization URL
     mcp_server_url = oauth_config["mcp_server_url"]
     callback_uri = f"{mcp_server_url}/oauth/callback"
@@ -164,7 +179,8 @@ async def oauth_login(request: Request) -> RedirectResponse | JSONResponse:
     digest = hashlib.sha256(code_verifier.encode()).digest()
     code_challenge = urlsafe_b64encode(digest).decode().rstrip("=")
 
-    # Store code_verifier in session for retrieval during callback (using state as key)
+    # Store code_verifier + nonce in session for retrieval during callback
+    # (using state as key)
     await storage.store_oauth_session(
         session_id=state,  # Use state as session ID
         client_id="browser-ui",
@@ -173,6 +189,7 @@ async def oauth_login(request: Request) -> RedirectResponse | JSONResponse:
         code_challenge=code_challenge,
         code_challenge_method="S256",
         mcp_authorization_code=code_verifier,  # Store code_verifier here temporarily
+        nonce=nonce,
         flow_type="browser",
         ttl_seconds=600,  # 10 minutes
     )
@@ -199,6 +216,7 @@ async def oauth_login(request: Request) -> RedirectResponse | JSONResponse:
             "response_type": "code",
             "scope": scopes,
             "state": state,
+            "nonce": nonce,
             "code_challenge": code_challenge,
             "code_challenge_method": "S256",
             "prompt": "consent",  # Ensure refresh token
@@ -219,12 +237,11 @@ async def oauth_login(request: Request) -> RedirectResponse | JSONResponse:
                 status_code=500,
             )
 
-        # Fetch authorization endpoint
-        async with nextcloud_httpx_client() as http_client:
-            response = await http_client.get(discovery_url)
-            response.raise_for_status()
-            discovery = response.json()
-            authorization_endpoint = discovery["authorization_endpoint"]
+        # Fetch authorization endpoint via the shared 5-minute discovery
+        # cache (PR #758 nit 5) so each browser login doesn't hit the IdP's
+        # discovery endpoint.
+        discovery = await get_oidc_discovery(discovery_url)
+        authorization_endpoint = discovery["authorization_endpoint"]
 
         # Include offline_access only if the IdP advertises it (or if
         # scopes_supported is absent from the discovery document).
@@ -257,6 +274,7 @@ async def oauth_login(request: Request) -> RedirectResponse | JSONResponse:
             "response_type": "code",
             "scope": scopes,
             "state": state,
+            "nonce": nonce,
             "code_challenge": code_challenge,
             "code_challenge_method": "S256",
             "prompt": "consent",  # Ensure refresh token
@@ -336,13 +354,17 @@ async def oauth_login_callback(request: Request) -> RedirectResponse | HTMLRespo
     oauth_client = oauth_ctx["oauth_client"]
     oauth_config = oauth_ctx["config"]
 
-    # Retrieve code_verifier and redirect URL from session storage
+    # Retrieve code_verifier, nonce, and redirect URL from session storage
     code_verifier = ""
+    nonce: str | None = None
     next_url = "/app"  # Default redirect
     oauth_session = await storage.get_oauth_session(state)
     if oauth_session:
         # code_verifier was stored in mcp_authorization_code field
         code_verifier = oauth_session.get("mcp_authorization_code", "")
+        # nonce bound to this auth request — verified against the ID token
+        # below (PR #758 finding 2).
+        nonce = oauth_session.get("nonce")
         # next_url was stored in client_redirect_uri field — re-validate at
         # read-time as defense-in-depth (issue #758 finding 3). The session
         # row could have been written by an older code path or reused.
@@ -483,6 +505,7 @@ async def oauth_login_callback(request: Request) -> RedirectResponse | HTMLRespo
             id_token,
             discovery_url=verification_discovery_url,
             expected_audience=verification_audience,
+            expected_nonce=nonce,
         )
     except IdTokenVerificationError as e:
         logger.error("ID token verification failed: %s", e)
@@ -673,21 +696,21 @@ async def _revoke_refresh_token_at_idp(oauth_ctx: dict, refresh_token: str) -> N
         if not discovery_url:
             return
 
+        # Re-use the shared 5-minute discovery cache (PR #758 nit 6) so a
+        # burst of logouts doesn't hammer the IdP's discovery endpoint.
+        discovery = await get_oidc_discovery(discovery_url)
+        revocation_endpoint = discovery.get("revocation_endpoint")
+        if not revocation_endpoint:
+            logger.debug("IdP advertises no revocation_endpoint; skipping")
+            return
+
+        client_id = cfg.get("client_id") or settings.oidc_client_id
+        client_secret = cfg.get("client_secret") or settings.oidc_client_secret
+        if not (client_id and client_secret):
+            logger.debug("No OIDC client credentials available for revocation")
+            return
+
         async with nextcloud_httpx_client() as http_client:
-            discovery_response = await http_client.get(discovery_url)
-            discovery_response.raise_for_status()
-            discovery = discovery_response.json()
-            revocation_endpoint = discovery.get("revocation_endpoint")
-            if not revocation_endpoint:
-                logger.debug("IdP advertises no revocation_endpoint; skipping")
-                return
-
-            client_id = cfg.get("client_id") or settings.oidc_client_id
-            client_secret = cfg.get("client_secret") or settings.oidc_client_secret
-            if not (client_id and client_secret):
-                logger.debug("No OIDC client credentials available for revocation")
-                return
-
             response = await http_client.post(
                 revocation_endpoint,
                 data={
diff --git a/nextcloud_mcp_server/auth/oauth_routes.py b/nextcloud_mcp_server/auth/oauth_routes.py
index 53c804ea..2f6de955 100644
--- a/nextcloud_mcp_server/auth/oauth_routes.py
+++ b/nextcloud_mcp_server/auth/oauth_routes.py
@@ -954,6 +954,28 @@ async def _oauth_callback_as_proxy(
         f"(token_type={nc_token_response.get('token_type')})"
     )
 
+    # Verify the ID token signature + claims before caching the response
+    # (PR #758 finding 1). Without this, a compromised IdP or tampered
+    # transport could plant arbitrary identity claims into the proxy code
+    # entry that gets handed back to the MCP client. Mirrors the
+    # verification done in oauth_callback_nextcloud.
+    id_token = nc_token_response.get("id_token")
+    try:
+        await verify_id_token(
+            id_token,
+            discovery_url=discovery_url,
+            expected_audience=mcp_server_client_id,
+        )
+    except IdTokenVerificationError as e:
+        logger.error("AS proxy: ID token verification failed: %s", e)
+        return JSONResponse(
+            {
+                "error": "invalid_token",
+                "error_description": "ID token failed verification",
+            },
+            status_code=400,
+        )
+
     # Generate a proxy authorization code for the client
     proxy_code = secrets.token_urlsafe(32)
     _proxy_codes[proxy_code] = ProxyCodeEntry(
diff --git a/nextcloud_mcp_server/auth/storage.py b/nextcloud_mcp_server/auth/storage.py
index a9fc9a33..691c1cc2 100644
--- a/nextcloud_mcp_server/auth/storage.py
+++ b/nextcloud_mcp_server/auth/storage.py
@@ -917,6 +917,7 @@ class RefreshTokenStorage:
         flow_type: str = "hybrid",
         is_provisioning: bool = False,
         requested_scopes: str | None = None,
+        nonce: str | None = None,
         ttl_seconds: int = 600,  # 10 minutes
     ) -> None:
         """
@@ -933,6 +934,8 @@ class RefreshTokenStorage:
             flow_type: Type of flow ('hybrid', 'flow1', 'flow2')
             is_provisioning: Whether this is a Flow 2 provisioning session
             requested_scopes: Requested OAuth scopes
+            nonce: OIDC ``nonce`` value bound to this auth request, returned
+                in the ID token and verified on callback (PR #758 finding 2).
             ttl_seconds: Session TTL in seconds
         """
         if not self._initialized:
@@ -947,8 +950,8 @@ class RefreshTokenStorage:
                 INSERT INTO oauth_sessions
                 (session_id, client_id, client_redirect_uri, state, code_challenge,
                  code_challenge_method, mcp_authorization_code, flow_type,
-                 is_provisioning, requested_scopes, created_at, expires_at)
-                VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+                 is_provisioning, requested_scopes, nonce, created_at, expires_at)
+                VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
                 """,
                 (
                     session_id,
@@ -961,6 +964,7 @@ class RefreshTokenStorage:
                     flow_type,
                     is_provisioning,
                     requested_scopes,
+                    nonce,
                     now,
                     expires_at,
                 ),
diff --git a/nextcloud_mcp_server/auth/token_utils.py b/nextcloud_mcp_server/auth/token_utils.py
index b13f411d..7903ac34 100644
--- a/nextcloud_mcp_server/auth/token_utils.py
+++ b/nextcloud_mcp_server/auth/token_utils.py
@@ -52,6 +52,17 @@ async def _get_cached(
     return data
 
 
+async def get_oidc_discovery(discovery_url: str) -> dict[str, Any]:
+    """Return the cached OIDC discovery document for *discovery_url*.
+
+    Shares the 5-minute discovery cache used by `verify_id_token`, so a
+    callback that does discovery → token-exchange → ID-token verification
+    reuses one HTTP round-trip instead of three. Public alias for `_get_cached`
+    against `_discovery_cache` (PR #758 nits 5 & 6).
+    """
+    return await _get_cached(_discovery_cache, discovery_url)
+
+
 async def verify_id_token(
     id_token: str,
     *,
diff --git a/nextcloud_mcp_server/server/oauth_tools.py b/nextcloud_mcp_server/server/oauth_tools.py
index 90769bf5..1ae62e79 100644
--- a/nextcloud_mcp_server/server/oauth_tools.py
+++ b/nextcloud_mcp_server/server/oauth_tools.py
@@ -9,7 +9,6 @@ import logging
 import os
 import secrets
 from datetime import datetime, timezone
-from typing import Optional
 from urllib.parse import urlencode
 
 from mcp.server.fastmcp import Context
@@ -18,7 +17,7 @@ from pydantic import BaseModel, Field
 
 from nextcloud_mcp_server.auth import require_scopes
 from nextcloud_mcp_server.auth.astrolabe_client import AstrolabeClient
-from nextcloud_mcp_server.auth.storage import RefreshTokenStorage
+from nextcloud_mcp_server.auth.storage import get_shared_storage
 from nextcloud_mcp_server.auth.token_broker import TokenBrokerService
 
 # Re-export for backward compatibility — canonical location is auth.token_utils
@@ -34,17 +33,17 @@ class ProvisioningStatus(BaseModel):
     """Status of Nextcloud provisioning for a user."""
 
     is_provisioned: bool = Field(description="Whether Nextcloud access is provisioned")
-    provisioned_at: Optional[str] = Field(
+    provisioned_at: str | None = Field(
         None, description="ISO timestamp when provisioned"
     )
-    credential_type: Optional[str] = Field(
+    credential_type: str | None = Field(
         None, description="Type of credential ('refresh_token' or 'app_password')"
     )
-    client_id: Optional[str] = Field(
+    client_id: str | None = Field(
         None, description="Client ID that initiated the original Flow 1"
     )
-    scopes: Optional[list[str]] = Field(None, description="Granted scopes")
-    flow_type: Optional[str] = Field(
+    scopes: list[str] | None = Field(None, description="Granted scopes")
+    flow_type: str | None = Field(
         None, description="Type of flow used ('hybrid', 'flow1', 'flow2')"
     )
 
@@ -53,7 +52,7 @@ class ProvisioningResult(BaseModel):
     """Result of provisioning attempt."""
 
     success: bool = Field(description="Whether provisioning was initiated")
-    provisioning_url: Optional[str] = Field(
+    provisioning_url: str | None = Field(
         None, description="URL to Astrolabe settings for provisioning background sync"
     )
     message: str = Field(description="Status message for the user")
@@ -122,8 +121,7 @@ async def get_provisioning_status(ctx: Context, user_id: str) -> ProvisioningSta
     logger.info(
         f"  get_provisioning_status: Looking up refresh token for user_id={user_id}"
     )
-    storage = RefreshTokenStorage.from_env()
-    await storage.initialize()
+    storage = await get_shared_storage()
 
     token_data = await storage.get_refresh_token(user_id)
 
@@ -291,8 +289,7 @@ async def revoke_nextcloud_access(ctx: Context, user_id: str) -> RevocationResul
             )
 
         # Initialize Token Broker to handle revocation
-        storage = RefreshTokenStorage.from_env()
-        await storage.initialize()
+        storage = await get_shared_storage()
 
         # Get OAuth client credentials from storage
         client_creds = await storage.get_oauth_client()
@@ -420,8 +417,7 @@ async def check_logged_in(ctx: Context, user_id: str) -> str:
         state = secrets.token_urlsafe(32)
 
         # Store state in session for validation on callback
-        storage = RefreshTokenStorage.from_env()
-        await storage.initialize()
+        storage = await get_shared_storage()
 
         # Create OAuth session for Flow 2
         session_id = f"flow2_{user_id}_{secrets.token_hex(8)}"
diff --git a/tests/unit/test_oauth_callback_session_cleanup.py b/tests/unit/test_oauth_callback_session_cleanup.py
index 3d908896..1f84f678 100644
--- a/tests/unit/test_oauth_callback_session_cleanup.py
+++ b/tests/unit/test_oauth_callback_session_cleanup.py
@@ -9,6 +9,11 @@ storage layer to confirm the row is gone after the callback runs.
 We mock everything *after* the deletion (discovery + token exchange +
 ID token verification) so the test focuses on the cleanup contract,
 not the OAuth wire protocol.
+
+Also pins the AS-proxy callback's ID-token verification rejection path
+introduced in PR #758 finding 1 (auto-review): a forged or unsigned
+id_token must surface as a 400 ``invalid_token`` JSONResponse and must
+not register a proxy code.
 """
 
 import tempfile
@@ -19,8 +24,15 @@ import httpx
 import pytest
 from cryptography.fernet import Fernet
 
-from nextcloud_mcp_server.auth.oauth_routes import oauth_callback_nextcloud
+from nextcloud_mcp_server.auth.oauth_routes import (
+    ASProxySession,
+    _as_proxy_sessions,
+    _oauth_callback_as_proxy,
+    _proxy_codes,
+    oauth_callback_nextcloud,
+)
 from nextcloud_mcp_server.auth.storage import RefreshTokenStorage
+from nextcloud_mcp_server.auth.token_utils import IdTokenVerificationError
 
 pytestmark = pytest.mark.unit
 
@@ -170,3 +182,85 @@ async def test_callback_no_session_row_does_not_crash(storage):
 
     # No crash, no row, no surprises.
     assert await storage.get_oauth_session(state) is None
+
+
+# ---------------------------------------------------------------------------
+# AS proxy callback (PR #758 finding 1): ID-token verification rejection
+# ---------------------------------------------------------------------------
+
+
+def _build_as_proxy_request(*, code: str, state: str):
+    request = MagicMock()
+    request.query_params = {"code": code, "state": state}
+    request.app.state.oauth_context = {
+        "config": {
+            "discovery_url": "https://idp.example.com/.well-known/openid-configuration",
+            "mcp_server_url": "https://mcp.example.com",
+            "client_id": "mcp-server",
+            "client_secret": "mcp-secret",
+        }
+    }
+    return request
+
+
+async def test_as_proxy_rejects_invalid_id_token():
+    """Forged/unsigned id_token in the IdP token response → 400 invalid_token.
+
+    Pins PR #758 finding 1. Without verification a compromised IdP or
+    tampered transport could plant arbitrary identity claims into the
+    cached ProxyCodeEntry that downstream clients pick up.
+    """
+    server_state = "as-proxy-state-rejected"
+    _as_proxy_sessions[server_state] = ASProxySession(
+        client_id="mcp-client",
+        client_redirect_uri="http://127.0.0.1:9999/callback",
+        client_state="client-state-xyz",
+        code_challenge="challenge",
+        code_challenge_method="S256",
+        requested_scopes="openid",
+    )
+    _proxy_codes.clear()
+
+    request = _build_as_proxy_request(code="auth-code", state=server_state)
+
+    fake_discovery = {
+        "token_endpoint": "https://idp.example.com/token",
+        "issuer": "https://idp.example.com",
+    }
+    fake_token_response = MagicMock(status_code=200)
+    fake_token_response.json.return_value = {
+        "access_token": "ac-tok",
+        "refresh_token": "rf-tok",
+        "id_token": "forged.id.token",
+        "token_type": "Bearer",
+    }
+
+    fake_http = MagicMock()
+    fake_http.post = AsyncMock(return_value=fake_token_response)
+    fake_http.__aenter__ = AsyncMock(return_value=fake_http)
+    fake_http.__aexit__ = AsyncMock(return_value=None)
+
+    with (
+        patch(
+            "nextcloud_mcp_server.auth.oauth_routes._get_cached_discovery",
+            new=AsyncMock(return_value=fake_discovery),
+        ),
+        patch(
+            "nextcloud_mcp_server.auth.oauth_routes.nextcloud_httpx_client",
+            return_value=fake_http,
+        ),
+        patch(
+            "nextcloud_mcp_server.auth.oauth_routes.verify_id_token",
+            new=AsyncMock(side_effect=IdTokenVerificationError("bad signature")),
+        ),
+    ):
+        response = await _oauth_callback_as_proxy(request, server_state)
+
+    assert response.status_code == 400
+    body = bytes(response.body).decode()
+    assert "invalid_token" in body
+    # Critical: the proxy code store must not have grown — a rejected
+    # callback must not be turned into a redeemable proxy code.
+    assert _proxy_codes == {}
+    # And the session has been popped (one-time use).
+    assert server_state not in _as_proxy_sessions
diff --git a/tests/unit/test_oauth_logout.py b/tests/unit/test_oauth_logout.py
index b8629ace..095f81c1 100644
--- a/tests/unit/test_oauth_logout.py
+++ b/tests/unit/test_oauth_logout.py
@@ -20,6 +20,7 @@ import pytest
 from cryptography.fernet import Fernet
 from starlette.requests import HTTPConnection
 
+from nextcloud_mcp_server.auth import token_utils
 from nextcloud_mcp_server.auth.browser_oauth_routes import (
     _revoke_refresh_token_at_idp,
     oauth_logout,
@@ -30,6 +31,20 @@ from nextcloud_mcp_server.auth.storage import RefreshTokenStorage
 pytestmark = pytest.mark.unit
 
 
+@pytest.fixture(autouse=True)
+def _clear_oidc_discovery_cache():
+    """Reset the shared discovery cache so tests don't see each other's fetches.
+
+    ``_revoke_refresh_token_at_idp`` was changed (PR #758 nit 6) to use
+    ``token_utils.get_oidc_discovery`` which caches for 5 minutes — without
+    this clear, the second test in the file would see the first test's
+    discovery doc and skip the MockTransport call.
+    """
+    token_utils._discovery_cache.clear()
+    yield
+    token_utils._discovery_cache.clear()
+
+
 # ---------------------------------------------------------------------------
 # storage fixture (real SQLite backend; lighter than mocking every call)
 # ---------------------------------------------------------------------------
@@ -337,9 +352,17 @@ async def test_revoke_helper_posts_to_revocation_endpoint():
         kwargs["transport"] = transport
         return httpx.AsyncClient(**kwargs)
 
-    with patch(
-        "nextcloud_mcp_server.auth.browser_oauth_routes.nextcloud_httpx_client",
-        side_effect=fake_client,
+    # Discovery now goes through token_utils.get_oidc_discovery (PR #758 nit
+    # 6); revocation POST still uses browser_oauth_routes' httpx client.
+    with (
+        patch(
+            "nextcloud_mcp_server.auth.browser_oauth_routes.nextcloud_httpx_client",
+            side_effect=fake_client,
+        ),
+        patch(
+            "nextcloud_mcp_server.auth.token_utils.nextcloud_httpx_client",
+            side_effect=fake_client,
+        ),
     ):
         await _revoke_refresh_token_at_idp(
             {
@@ -373,9 +396,15 @@ async def test_revoke_helper_skips_when_no_revocation_endpoint():
         kwargs["transport"] = transport
         return httpx.AsyncClient(**kwargs)
 
-    with patch(
-        "nextcloud_mcp_server.auth.browser_oauth_routes.nextcloud_httpx_client",
-        side_effect=fake_client,
+    with (
+        patch(
+            "nextcloud_mcp_server.auth.browser_oauth_routes.nextcloud_httpx_client",
+            side_effect=fake_client,
+        ),
+        patch(
+            "nextcloud_mcp_server.auth.token_utils.nextcloud_httpx_client",
+            side_effect=fake_client,
+        ),
     ):
         # Returns None and does not raise
         result = await _revoke_refresh_token_at_idp(
@@ -403,9 +432,15 @@ async def test_revoke_helper_silent_on_idp_error():
         kwargs["transport"] = transport
         return httpx.AsyncClient(**kwargs)
 
-    with patch(
-        "nextcloud_mcp_server.auth.browser_oauth_routes.nextcloud_httpx_client",
-        side_effect=fake_client,
+    with (
+        patch(
+            "nextcloud_mcp_server.auth.browser_oauth_routes.nextcloud_httpx_client",
+            side_effect=fake_client,
+        ),
+        patch(
+            "nextcloud_mcp_server.auth.token_utils.nextcloud_httpx_client",
+            side_effect=fake_client,
+        ),
     ):
         result = await _revoke_refresh_token_at_idp(
             {