Merge pull request #761 from cbcoutinho/fix/webhooks-api-basic-auth

fix(webhooks): use app-password basic auth for NC API calls

nextcloud_mcp_server/api/_auth.py

@@ -0,0 +1,48 @@
+"""Credential resolution helpers for non-MCP-Context API endpoints.
+
+Starlette routes (e.g. ``api/webhooks.py``) authenticate the inbound request
+via OAuth bearer validation, then need to make Nextcloud API calls on behalf
+of that user. Per ADR-022 / ``docs/login-flow-v2.md`` the data leg to
+Nextcloud always uses **HTTP Basic Auth with the user's app password**, never
+the OAuth token. This module resolves that credential pair.
+
+The MCP tool path uses ``context.get_client(ctx)``; this is the equivalent
+helper for callers that have a validated ``user_id`` but no MCP ``Context``.
+"""
+
+from nextcloud_mcp_server.auth.scope_authorization import ProvisioningRequiredError
+from nextcloud_mcp_server.auth.storage import get_shared_storage
+
+
+async def get_basic_auth_for_user(user_id: str) -> tuple[str, str]:
+    """Resolve ``(username, app_password)`` for an OAuth-validated user.
+
+    Reads the per-user app password provisioned via Login Flow v2 from
+    encrypted SQLite storage. The username returned is the actual Nextcloud
+    username recorded at provisioning time (which may differ from the IdP
+    user-id when an external IdP is configured).
+
+    Args:
+        user_id: MCP user identifier extracted from a validated OAuth token.
+
+    Returns:
+        Tuple ``(username, app_password)`` ready to pass to
+        ``httpx.BasicAuth``.
+
+    Raises:
+        ProvisioningRequiredError: No app password is stored for ``user_id``.
+            The caller should surface this to the client so the user can
+            complete Login Flow v2 (typically via ``nc_auth_provision_access``
+            or the Astrolabe settings page).
+    """
+    storage = await get_shared_storage()
+    app_data = await storage.get_app_password_with_scopes(user_id)
+    if not app_data:
+        raise ProvisioningRequiredError(
+            f"No Nextcloud app password provisioned for user {user_id!r}. "
+            "Complete Login Flow v2 (nc_auth_provision_access) before "
+            "calling this endpoint."
+        )
+
+    username = app_data.get("username") or user_id
+    return username, app_data["app_password"]

nextcloud_mcp_server/api/webhooks.py

@@ -6,18 +6,28 @@ These endpoints are used by the Nextcloud PHP app (Astrolabe) to:
 - Create, list, and delete webhook registrations
 
 All endpoints require OAuth bearer token authentication via UnifiedTokenVerifier.
+
+Auth model: the OAuth bearer is validated at the perimeter to identify the
+user (``validate_token_and_get_user``); calls to Nextcloud are then made with
+the user's stored app password via HTTP Basic Auth (see
+``docs/login-flow-v2.md`` and ADR-022). The OAuth bearer is NEVER forwarded
+to Nextcloud — that pattern depended on upstream user_oidc patches that were
+never merged and is incompatible with admin endpoints gated by
+``@PasswordConfirmationRequired``.
 """
 
 import logging
 
+import httpx
 from starlette.requests import Request
 from starlette.responses import JSONResponse
 
+from nextcloud_mcp_server.api._auth import get_basic_auth_for_user
 from nextcloud_mcp_server.api.management import (
     _sanitize_error_for_client,
-    extract_bearer_token,
     validate_token_and_get_user,
 )
+from nextcloud_mcp_server.auth.scope_authorization import ProvisioningRequiredError
 from nextcloud_mcp_server.auth.webhook_routes import webhook_auth_pair
 from nextcloud_mcp_server.client.webhooks import WebhooksClient
 
@@ -47,29 +57,19 @@ async def get_installed_apps(request: Request) -> JSONResponse:
         )
 
     try:
-        # Get Bearer token from request — forwarded to Nextcloud so the
+        username, app_password = await get_basic_auth_for_user(user_id)
-        # capabilities response includes per-user / per-app entries (anonymous
-        # capabilities omits notes, tables, forms etc.).
-        token = extract_bearer_token(request)
-        if not token:
-            raise ValueError("Missing Authorization header")
 
-        # Get Nextcloud host from OAuth context
         oauth_ctx = request.app.state.oauth_context
         nextcloud_host = oauth_ctx.get("config", {}).get("nextcloud_host", "")
-
         if not nextcloud_host:
             raise ValueError("Nextcloud host not configured")
 
-        # Use OCS v2 capabilities. The legacy /ocs/v1.php/cloud/apps endpoint is
+        # OCS v2 capabilities is keyed by app-id for every enabled app that
-        # admin-only AND @PasswordConfirmationRequired — neither is satisfiable
+        # implements OCSCapabilities — sufficient for the webhook presets UI
-        # via an OAuth bearer token, so it always 401s. Capabilities has no such
+        # without needing the admin-only /cloud/apps endpoint.
-        # gates and returns a map keyed by app id for every enabled app that
-        # implements OCSCapabilities, which is sufficient to populate the
-        # webhook presets UI.
         async with nextcloud_httpx_client(
             base_url=nextcloud_host,
-            headers={"Authorization": f"Bearer {token}"},
+            auth=httpx.BasicAuth(username, app_password),
             timeout=30.0,
         ) as client:
             response = await client.get(
@@ -87,6 +87,12 @@ async def get_installed_apps(request: Request) -> JSONResponse:
 
             return JSONResponse({"apps": apps})
 
+    except ProvisioningRequiredError as e:
+        logger.info("Provisioning required for user %s: %s", user_id, e)
+        return JSONResponse(
+            {"error": "Provisioning required", "message": str(e)},
+            status_code=428,
+        )
     except Exception as e:
         logger.error("Error getting installed apps for user %s: %s", user_id, e)
         return JSONResponse(
@@ -119,30 +125,28 @@ async def list_webhooks(request: Request) -> JSONResponse:
         )
 
     try:
-        # Get Bearer token from request
+        username, app_password = await get_basic_auth_for_user(user_id)
-        token = extract_bearer_token(request)
-        if not token:
-            raise ValueError("Missing Authorization header")
 
-        # Get Nextcloud host from OAuth context
         oauth_ctx = request.app.state.oauth_context
         nextcloud_host = oauth_ctx.get("config", {}).get("nextcloud_host", "")
-
         if not nextcloud_host:
             raise ValueError("Nextcloud host not configured")
 
-        # Create authenticated HTTP client
         async with nextcloud_httpx_client(
             base_url=nextcloud_host,
-            headers={"Authorization": f"Bearer {token}"},
+            auth=httpx.BasicAuth(username, app_password),
             timeout=30.0,
         ) as client:
-            # Use WebhooksClient to list webhooks
+            webhooks_client = WebhooksClient(client, username)
-            webhooks_client = WebhooksClient(client, user_id)
             webhooks = await webhooks_client.list_webhooks()
-
             return JSONResponse({"webhooks": webhooks})
 
+    except ProvisioningRequiredError as e:
+        logger.info("Provisioning required for user %s: %s", user_id, e)
+        return JSONResponse(
+            {"error": "Provisioning required", "message": str(e)},
+            status_code=428,
+        )
     except Exception as e:
         logger.error("Error listing webhooks for user %s: %s", user_id, e)
         return JSONResponse(
@@ -198,27 +202,21 @@ async def create_webhook(request: Request) -> JSONResponse:
                 status_code=400,
             )
 
-        # Get Bearer token from request
+        username, app_password = await get_basic_auth_for_user(user_id)
-        token = extract_bearer_token(request)
-        if not token:
-            raise ValueError("Missing Authorization header")
 
-        # Get Nextcloud host from OAuth context
         oauth_ctx = request.app.state.oauth_context
         nextcloud_host = oauth_ctx.get("config", {}).get("nextcloud_host", "")
-
         if not nextcloud_host:
             raise ValueError("Nextcloud host not configured")
 
-        # Create authenticated HTTP client
         async with nextcloud_httpx_client(
             base_url=nextcloud_host,
-            headers={"Authorization": f"Bearer {token}"},
+            auth=httpx.BasicAuth(username, app_password),
             timeout=30.0,
         ) as client:
-            # Use WebhooksClient to create webhook. Inject auth headers when
+            # Inject delivery auth headers when WEBHOOK_SECRET is configured so
-            # WEBHOOK_SECRET is configured so deliveries are authenticated.
+            # that webhook deliveries from Nextcloud back to us are authenticated.
-            webhooks_client = WebhooksClient(client, user_id)
+            webhooks_client = WebhooksClient(client, username)
             auth_method, auth_data = webhook_auth_pair()
             webhook_data = await webhooks_client.create_webhook(
                 event=event,
@@ -230,6 +228,12 @@ async def create_webhook(request: Request) -> JSONResponse:
 
             return JSONResponse({"webhook": webhook_data})
 
+    except ProvisioningRequiredError as e:
+        logger.info("Provisioning required for user %s: %s", user_id, e)
+        return JSONResponse(
+            {"error": "Provisioning required", "message": str(e)},
+            status_code=428,
+        )
     except Exception as e:
         logger.error("Error creating webhook for user %s: %s", user_id, e)
         return JSONResponse(
@@ -278,30 +282,28 @@ async def delete_webhook(request: Request) -> JSONResponse:
                 status_code=400,
             )
 
-        # Get Bearer token from request
+        username, app_password = await get_basic_auth_for_user(user_id)
-        token = extract_bearer_token(request)
-        if not token:
-            raise ValueError("Missing Authorization header")
 
-        # Get Nextcloud host from OAuth context
         oauth_ctx = request.app.state.oauth_context
         nextcloud_host = oauth_ctx.get("config", {}).get("nextcloud_host", "")
-
         if not nextcloud_host:
             raise ValueError("Nextcloud host not configured")
 
-        # Create authenticated HTTP client
         async with nextcloud_httpx_client(
             base_url=nextcloud_host,
-            headers={"Authorization": f"Bearer {token}"},
+            auth=httpx.BasicAuth(username, app_password),
             timeout=30.0,
         ) as client:
-            # Use WebhooksClient to delete webhook
+            webhooks_client = WebhooksClient(client, username)
-            webhooks_client = WebhooksClient(client, user_id)
             await webhooks_client.delete_webhook(webhook_id=webhook_id)
-
             return JSONResponse({"success": True, "message": "Webhook deleted"})
 
+    except ProvisioningRequiredError as e:
+        logger.info("Provisioning required for user %s: %s", user_id, e)
+        return JSONResponse(
+            {"error": "Provisioning required", "message": str(e)},
+            status_code=428,
+        )
     except Exception as e:
         logger.error("Error deleting webhook for user %s: %s", user_id, e)
         return JSONResponse(

tests/unit/test_management_apps_endpoint.py

@@ -1,21 +1,23 @@
 """
 Unit tests for the Management API /api/v1/apps endpoint.
 
-These tests cover the regression where /api/v1/apps proxied to
+The handler hits ``/ocs/v2.php/cloud/capabilities`` (not the legacy admin-only
-/ocs/v1.php/cloud/apps — an admin-only and @PasswordConfirmationRequired
+``/ocs/v1.php/cloud/apps`` which was ``@PasswordConfirmationRequired``) and
-endpoint that always 401s for OAuth bearer tokens. The handler now uses
+authenticates via the user's stored Login Flow v2 app password using HTTP
-/ocs/v2.php/cloud/capabilities, which accepts the bearer and returns an
+Basic Auth. The OAuth bearer is **never** forwarded to Nextcloud (see
-authenticated capability map keyed by app id.
+``docs/login-flow-v2.md`` and ADR-022).
 """
 
 from unittest.mock import AsyncMock, MagicMock
 
+import httpx
 import pytest
 from starlette.applications import Starlette
 from starlette.routing import Route
 from starlette.testclient import TestClient
 
 from nextcloud_mcp_server.api.webhooks import get_installed_apps
+from nextcloud_mcp_server.auth.scope_authorization import ProvisioningRequiredError
 
 pytestmark = pytest.mark.unit
 
@@ -33,8 +35,19 @@ def _patch_token_validation(mocker, user_id: str = "admin") -> None:
     )
 
 
-def _patch_outbound_client(mocker, response: MagicMock) -> AsyncMock:
+def _patch_basic_auth(
-    """Patch the outbound httpx client; return the mocked .get() AsyncMock."""
+    mocker, username: str = "admin", app_password: str = "stored-app-pwd"
+) -> AsyncMock:
+    """Patch get_basic_auth_for_user to return canned credentials."""
+    return mocker.patch(
+        "nextcloud_mcp_server.api.webhooks.get_basic_auth_for_user",
+        new=AsyncMock(return_value=(username, app_password)),
+    )
+
+
+def _patch_outbound_client(mocker, response: MagicMock) -> MagicMock:
+    """Patch the outbound httpx client; return the factory MagicMock so tests
+    can introspect the kwargs (esp. ``auth=``) it was called with."""
     mock_get = AsyncMock(return_value=response)
     mock_client = AsyncMock()
     mock_client.get = mock_get
@@ -48,7 +61,6 @@ def _patch_outbound_client(mocker, response: MagicMock) -> AsyncMock:
     mocker.patch(
         "nextcloud_mcp_server.api.webhooks.nextcloud_httpx_client", mock_factory
     )
-    # Return both so tests can assert on factory kwargs and call args
     mock_factory.attach_mock(mock_get, "get")
     return mock_factory
 
@@ -63,6 +75,7 @@ def _capabilities_response(capabilities: dict[str, dict]) -> MagicMock:
 async def test_returns_sorted_capability_keys(mocker):
     """Happy path: handler hits OCS v2 capabilities and returns sorted app keys."""
     _patch_token_validation(mocker)
+    _patch_basic_auth(mocker)
     response = _capabilities_response(
         {
             "notes": {"api_version": "1.4"},
@@ -82,22 +95,24 @@ async def test_returns_sorted_capability_keys(mocker):
     assert http_response.status_code == 200
     assert http_response.json() == {"apps": ["core", "files", "notes", "tables"]}
 
-    # Regression check: outbound URL is OCS v2 capabilities, NOT v1 cloud/apps.
+    # Outbound URL is OCS v2 capabilities, NOT v1 cloud/apps.
-    # /ocs/v1.php/cloud/apps was admin-only + @PasswordConfirmationRequired
-    # which always 401s for OAuth bearer tokens — that was the bug.
     factory.get.assert_awaited_once()
     called_path = factory.get.call_args.args[0]
     assert called_path == "/ocs/v2.php/cloud/capabilities"
-    assert "/cloud/apps" not in called_path
 
-    # Bearer token forwarded so authenticated capabilities are returned
+    # Outbound auth is BasicAuth (NOT Bearer) — the OAuth token must not be
-    factory_call_kwargs = factory.call_args.kwargs
+    # forwarded to Nextcloud per ADR-022 / docs/login-flow-v2.md.
-    assert factory_call_kwargs["headers"] == {"Authorization": "Bearer test-token"}
+    factory_kwargs = factory.call_args.kwargs
+    assert "headers" not in factory_kwargs or "Authorization" not in (
+        factory_kwargs.get("headers") or {}
+    )
+    assert isinstance(factory_kwargs["auth"], httpx.BasicAuth)
 
 
 async def test_empty_capabilities_returns_empty_list(mocker):
     """Empty capabilities map → empty apps list, not an error."""
     _patch_token_validation(mocker)
+    _patch_basic_auth(mocker)
     response = _capabilities_response({})
     _patch_outbound_client(mocker, response)
 
@@ -114,6 +129,7 @@ async def test_empty_capabilities_returns_empty_list(mocker):
 async def test_ocs_error_returns_500_with_sanitized_message(mocker):
     """Non-200 from Nextcloud OCS surfaces as a generic 500 to the caller."""
     _patch_token_validation(mocker)
+    _patch_basic_auth(mocker)
     error_response = MagicMock()
     error_response.status_code = 503
     _patch_outbound_client(mocker, error_response)
@@ -135,6 +151,7 @@ async def test_ocs_error_returns_500_with_sanitized_message(mocker):
 async def test_missing_nextcloud_host_returns_500(mocker):
     """Misconfigured oauth_context (no nextcloud_host) surfaces as 500."""
     _patch_token_validation(mocker)
+    _patch_basic_auth(mocker)
     response = _capabilities_response({})
     _patch_outbound_client(mocker, response)
 
@@ -149,17 +166,22 @@ async def test_missing_nextcloud_host_returns_500(mocker):
     assert http_response.status_code == 500
 
 
-async def test_missing_authorization_returns_500(mocker):
+async def test_unprovisioned_user_returns_428(mocker):
-    """When token validation passes but Authorization header is absent, the
+    """Users without a stored app password get HTTP 428 (Precondition Required,
-    handler can't construct the outbound bearer header — returns 500 with a
+    RFC 6585) so the client can surface a 'complete Login Flow v2' UX rather
-    sanitized message."""
+    than a generic 500. 428 is the right semantic — the request requires a
+    prerequisite step (provisioning) before it can succeed."""
     _patch_token_validation(mocker)
-    response = _capabilities_response({})
+    mocker.patch(
-    _patch_outbound_client(mocker, response)
+        "nextcloud_mcp_server.api.webhooks.get_basic_auth_for_user",
+        new=AsyncMock(side_effect=ProvisioningRequiredError("not provisioned")),
+    )
 
     app = _build_test_app()
     client = TestClient(app)
-    # No Authorization header
+    http_response = client.get(
-    http_response = client.get("/api/v1/apps")
+        "/api/v1/apps", headers={"Authorization": "Bearer test-token"}
+    )
 
-    assert http_response.status_code == 500
+    assert http_response.status_code == 428
+    assert http_response.json()["error"] == "Provisioning required"

tests/unit/test_webhooks_api_auth.py

@@ -0,0 +1,314 @@
+"""Unit tests asserting the webhook API endpoints authenticate to Nextcloud
+with an app-password BasicAuth credential — never by forwarding the inbound
+OAuth bearer token.
+
+Per ADR-022 / ``docs/login-flow-v2.md`` the data leg from MCP server to
+Nextcloud always uses HTTP Basic Auth with a per-user app password obtained
+via Login Flow v2. Forwarding OAuth bearers to Nextcloud was the obsolete
+pre-ADR-022 pattern; it relies on upstream user_oidc patches that were never
+merged and is incompatible with admin endpoints gated by
+``@PasswordConfirmationRequired`` (e.g. ``webhook_listeners``).
+"""
+
+from unittest.mock import AsyncMock, MagicMock
+
+import httpx
+import pytest
+from starlette.applications import Starlette
+from starlette.routing import Route
+from starlette.testclient import TestClient
+
+from nextcloud_mcp_server.api.webhooks import (
+    create_webhook,
+    delete_webhook,
+    list_webhooks,
+)
+from nextcloud_mcp_server.auth.scope_authorization import ProvisioningRequiredError
+
+pytestmark = pytest.mark.unit
+
+
+def _build_test_app() -> Starlette:
+    app = Starlette(
+        routes=[
+            Route("/api/v1/webhooks", list_webhooks, methods=["GET"]),
+            Route("/api/v1/webhooks", create_webhook, methods=["POST"]),
+            Route("/api/v1/webhooks/{webhook_id}", delete_webhook, methods=["DELETE"]),
+        ]
+    )
+    app.state.oauth_context = {"config": {"nextcloud_host": "http://nc.test"}}
+    return app
+
+
+def _patch_token_validation(mocker, user_id: str = "admin") -> None:
+    mocker.patch(
+        "nextcloud_mcp_server.api.webhooks.validate_token_and_get_user",
+        new=AsyncMock(return_value=(user_id, {"sub": user_id})),
+    )
+
+
+def _patch_basic_auth(
+    mocker, username: str = "admin", app_password: str = "stored-app-pwd"
+) -> AsyncMock:
+    return mocker.patch(
+        "nextcloud_mcp_server.api.webhooks.get_basic_auth_for_user",
+        new=AsyncMock(return_value=(username, app_password)),
+    )
+
+
+def _patch_webhooks_client(mocker, **methods) -> MagicMock:
+    """Replace WebhooksClient with a stub. ``methods`` maps method name →
+    return value for AsyncMock(side_effect/return_value)."""
+    instance = MagicMock()
+    for name, value in methods.items():
+        setattr(instance, name, AsyncMock(return_value=value))
+
+    cls = MagicMock(return_value=instance)
+    mocker.patch("nextcloud_mcp_server.api.webhooks.WebhooksClient", cls)
+    return cls
+
+
+def _patch_outbound_client_factory(mocker) -> MagicMock:
+    """Patch nextcloud_httpx_client so we can assert on the kwargs (esp.
+    ``auth=``) the handler called it with."""
+    mock_client = AsyncMock()
+    mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+    mock_client.__aexit__ = AsyncMock(return_value=False)
+
+    factory = MagicMock(return_value=mock_client)
+    mocker.patch("nextcloud_mcp_server.api.webhooks.nextcloud_httpx_client", factory)
+    return factory
+
+
+def _assert_basic_auth_not_bearer(factory: MagicMock) -> None:
+    """Outbound httpx kwargs must use ``auth=BasicAuth(...)`` and NOT a
+    Bearer ``Authorization`` header."""
+    factory.assert_called_once()
+    kwargs = factory.call_args.kwargs
+    assert isinstance(kwargs["auth"], httpx.BasicAuth), (
+        "Outbound NC request must use BasicAuth, not bearer-header forwarding"
+    )
+    headers = kwargs.get("headers") or {}
+    assert "Authorization" not in headers, (
+        "Outbound NC request must NOT carry an Authorization header — "
+        "the OAuth bearer must never be forwarded to Nextcloud"
+    )
+
+
+# ---------------------------------------------------------------------------
+# list_webhooks
+# ---------------------------------------------------------------------------
+
+
+async def test_list_webhooks_uses_basic_auth(mocker):
+    _patch_token_validation(mocker)
+    _patch_basic_auth(mocker, username="alice", app_password="alice-pwd")
+    factory = _patch_outbound_client_factory(mocker)
+    _patch_webhooks_client(
+        mocker, list_webhooks=[{"id": 1, "event": "test", "uri": "http://x"}]
+    )
+
+    client = TestClient(_build_test_app())
+    resp = client.get("/api/v1/webhooks", headers={"Authorization": "Bearer mcp-token"})
+
+    assert resp.status_code == 200
+    assert resp.json() == {"webhooks": [{"id": 1, "event": "test", "uri": "http://x"}]}
+    _assert_basic_auth_not_bearer(factory)
+
+
+async def test_list_webhooks_returns_428_when_unprovisioned(mocker):
+    _patch_token_validation(mocker)
+    mocker.patch(
+        "nextcloud_mcp_server.api.webhooks.get_basic_auth_for_user",
+        new=AsyncMock(side_effect=ProvisioningRequiredError("not provisioned")),
+    )
+
+    client = TestClient(_build_test_app())
+    resp = client.get("/api/v1/webhooks", headers={"Authorization": "Bearer mcp-token"})
+
+    assert resp.status_code == 428
+    assert resp.json()["error"] == "Provisioning required"
+
+
+# ---------------------------------------------------------------------------
+# create_webhook
+# ---------------------------------------------------------------------------
+
+
+async def test_create_webhook_uses_basic_auth(mocker):
+    _patch_token_validation(mocker)
+    _patch_basic_auth(mocker, username="bob", app_password="bob-pwd")
+    factory = _patch_outbound_client_factory(mocker)
+    _patch_webhooks_client(
+        mocker,
+        create_webhook={"id": 42, "event": "OCP\\Events\\NodeCreated"},
+    )
+    mocker.patch(
+        "nextcloud_mcp_server.api.webhooks.webhook_auth_pair",
+        return_value=("none", None),
+    )
+
+    client = TestClient(_build_test_app())
+    resp = client.post(
+        "/api/v1/webhooks",
+        headers={"Authorization": "Bearer mcp-token"},
+        json={
+            "event": "OCP\\Events\\NodeCreated",
+            "uri": "http://mcp:8000/webhooks/nextcloud",
+        },
+    )
+
+    assert resp.status_code == 200
+    assert resp.json() == {"webhook": {"id": 42, "event": "OCP\\Events\\NodeCreated"}}
+    _assert_basic_auth_not_bearer(factory)
+
+
+async def test_create_webhook_validates_required_fields(mocker):
+    _patch_token_validation(mocker)
+    _patch_basic_auth(mocker)
+
+    client = TestClient(_build_test_app())
+    resp = client.post(
+        "/api/v1/webhooks",
+        headers={"Authorization": "Bearer mcp-token"},
+        json={"event": "X"},  # missing uri
+    )
+
+    assert resp.status_code == 400
+
+
+async def test_create_webhook_returns_428_when_unprovisioned(mocker):
+    _patch_token_validation(mocker)
+    mocker.patch(
+        "nextcloud_mcp_server.api.webhooks.get_basic_auth_for_user",
+        new=AsyncMock(side_effect=ProvisioningRequiredError("not provisioned")),
+    )
+
+    client = TestClient(_build_test_app())
+    resp = client.post(
+        "/api/v1/webhooks",
+        headers={"Authorization": "Bearer mcp-token"},
+        json={"event": "X", "uri": "http://x"},
+    )
+
+    assert resp.status_code == 428
+    assert resp.json()["error"] == "Provisioning required"
+
+
+# ---------------------------------------------------------------------------
+# delete_webhook
+# ---------------------------------------------------------------------------
+
+
+async def test_delete_webhook_uses_basic_auth(mocker):
+    _patch_token_validation(mocker)
+    _patch_basic_auth(mocker, username="carol", app_password="carol-pwd")
+    factory = _patch_outbound_client_factory(mocker)
+    _patch_webhooks_client(mocker, delete_webhook=None)
+
+    client = TestClient(_build_test_app())
+    resp = client.delete(
+        "/api/v1/webhooks/99", headers={"Authorization": "Bearer mcp-token"}
+    )
+
+    assert resp.status_code == 200
+    assert resp.json() == {"success": True, "message": "Webhook deleted"}
+    _assert_basic_auth_not_bearer(factory)
+
+
+async def test_delete_webhook_rejects_non_integer_id(mocker):
+    _patch_token_validation(mocker)
+    _patch_basic_auth(mocker)
+
+    client = TestClient(_build_test_app())
+    resp = client.delete(
+        "/api/v1/webhooks/notanumber",
+        headers={"Authorization": "Bearer mcp-token"},
+    )
+
+    assert resp.status_code == 400
+
+
+async def test_delete_webhook_returns_428_when_unprovisioned(mocker):
+    _patch_token_validation(mocker)
+    mocker.patch(
+        "nextcloud_mcp_server.api.webhooks.get_basic_auth_for_user",
+        new=AsyncMock(side_effect=ProvisioningRequiredError("not provisioned")),
+    )
+
+    client = TestClient(_build_test_app())
+    resp = client.delete(
+        "/api/v1/webhooks/99",
+        headers={"Authorization": "Bearer mcp-token"},
+    )
+
+    assert resp.status_code == 428
+    assert resp.json()["error"] == "Provisioning required"
+
+
+# ---------------------------------------------------------------------------
+# get_basic_auth_for_user helper
+# ---------------------------------------------------------------------------
+
+
+async def test_get_basic_auth_for_user_resolves_username_and_password(mocker):
+    """Helper returns the stored Nextcloud username (not the OAuth user_id)
+    when one was recorded at provisioning time."""
+    from nextcloud_mcp_server.api._auth import get_basic_auth_for_user
+
+    storage = MagicMock()
+    storage.get_app_password_with_scopes = AsyncMock(
+        return_value={
+            "app_password": "encrypted-then-decrypted-pwd",
+            "scopes": ["notes.read"],
+            "username": "nc-username",
+            "created_at": "2026-01-01",
+            "updated_at": "2026-01-02",
+        }
+    )
+    mocker.patch(
+        "nextcloud_mcp_server.api._auth.get_shared_storage",
+        new=AsyncMock(return_value=storage),
+    )
+
+    username, password = await get_basic_auth_for_user("idp-user-id")
+    assert username == "nc-username"
+    assert password == "encrypted-then-decrypted-pwd"
+
+
+async def test_get_basic_auth_for_user_falls_back_to_user_id(mocker):
+    """When ``username`` is null in storage, the helper falls back to the
+    OAuth-issued user_id."""
+    from nextcloud_mcp_server.api._auth import get_basic_auth_for_user
+
+    storage = MagicMock()
+    storage.get_app_password_with_scopes = AsyncMock(
+        return_value={
+            "app_password": "pwd",
+            "scopes": None,
+            "username": None,
+            "created_at": "2026-01-01",
+            "updated_at": "2026-01-01",
+        }
+    )
+    mocker.patch(
+        "nextcloud_mcp_server.api._auth.get_shared_storage",
+        new=AsyncMock(return_value=storage),
+    )
+
+    username, _ = await get_basic_auth_for_user("admin")
+    assert username == "admin"
+
+
+async def test_get_basic_auth_for_user_raises_when_unprovisioned(mocker):
+    from nextcloud_mcp_server.api._auth import get_basic_auth_for_user
+
+    storage = MagicMock()
+    storage.get_app_password_with_scopes = AsyncMock(return_value=None)
+    mocker.patch(
+        "nextcloud_mcp_server.api._auth.get_shared_storage",
+        new=AsyncMock(return_value=storage),
+    )
+
+    with pytest.raises(ProvisioningRequiredError):
+        await get_basic_auth_for_user("admin")