From 3e4f9af9555df6fef78e22624778e655d3067173 Mon Sep 17 00:00:00 2001 From: Sameer Kankute Date: Mon, 27 Apr 2026 12:05:49 +0530 Subject: [PATCH 1/3] Add support for azure entra discovery endpoint --- .../mcp_server/mcp_server_manager.py | 41 +++++- .../mcp_server/test_mcp_server_manager.py | 130 ++++++++++++++++++ 2 files changed, 166 insertions(+), 5 deletions(-) diff --git a/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py b/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py index 251f271903b..6aaf37c91ec 100644 --- a/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py +++ b/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py @@ -1488,11 +1488,18 @@ class MCPServerManager: client = get_async_httpx_client(llm_provider=httpxSpecialProvider.MCP) response = await client.get(server_url) response.raise_for_status() - verbose_logger.warning( - "MCP OAuth discovery unexpectedly succeeded for %s; server did not challenge", - server_url, + ( + authorization_servers, + resource_scopes, + ) = await self._attempt_well_known_discovery(server_url) + metadata = await self._fetch_authorization_server_metadata( + authorization_servers ) - raise RuntimeError("OAuth discovery must not succeed without a challenge") + if metadata is None and resource_scopes: + return MCPOAuthMetadata(scopes=resource_scopes) + if metadata is not None and resource_scopes: + metadata.scopes = resource_scopes + return metadata except HTTPStatusError as exc: verbose_logger.debug( "MCP OAuth discovery for %s received status error: %s", @@ -1674,6 +1681,9 @@ class MCPServerManager: f"{base}/.well-known/oauth-authorization-server/{path}" ) candidate_urls.append(f"{base}/.well-known/openid-configuration/{path}") + candidate_urls.append( + f"{issuer_url.rstrip('/')}/.well-known/openid-configuration" + ) candidate_urls.append(f"{base}/.well-known/oauth-authorization-server") candidate_urls.append(f"{base}/.well-known/openid-configuration") candidate_urls.append(issuer_url.rstrip("/")) @@ -1713,7 +1723,28 @@ class MCPServerManager: ): return metadata - return None + return self._build_azure_authorization_server_metadata(parsed) + + @staticmethod + def _build_azure_authorization_server_metadata( + parsed_issuer_url: Any, + ) -> Optional[MCPOAuthMetadata]: + path_parts = [ + part for part in (parsed_issuer_url.path or "").split("/") if part + ] + if ( + parsed_issuer_url.netloc != "login.microsoftonline.com" + or len(path_parts) != 2 + or path_parts[1] != "v2.0" + ): + return None + + tenant = path_parts[0] + base = f"{parsed_issuer_url.scheme}://{parsed_issuer_url.netloc}/{tenant}" + return MCPOAuthMetadata( + authorization_url=f"{base}/oauth2/v2.0/authorize", + token_url=f"{base}/oauth2/v2.0/token", + ) @staticmethod def _decrypt_credential_field( diff --git a/tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_server_manager.py b/tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_server_manager.py index 447c28078ec..8614cb3ba72 100644 --- a/tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_server_manager.py +++ b/tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_server_manager.py @@ -728,6 +728,136 @@ class TestMCPServerManager: ] assert scopes == ["read", "write"] + @pytest.mark.asyncio + async def test_descovery_metadata_probes_well_known_when_server_does_not_challenge( + self, + ): + manager = MCPServerManager() + + mock_response = MagicMock() + mock_response.raise_for_status = MagicMock() + + mock_client = MagicMock() + mock_client.get = AsyncMock(return_value=mock_response) + + mock_metadata = MCPOAuthMetadata( + scopes=None, + authorization_url="https://login.microsoftonline.com/tenant/oauth2/v2.0/authorize", + token_url="https://login.microsoftonline.com/tenant/oauth2/v2.0/token", + registration_url=None, + ) + + with ( + patch( + "litellm.proxy._experimental.mcp_server.mcp_server_manager.get_async_httpx_client", + return_value=mock_client, + ), + patch.object( + manager, + "_attempt_well_known_discovery", + AsyncMock( + return_value=( + ["https://login.microsoftonline.com/test-tenant-id/v2.0"], + ["api://some-scope/.default"], + ) + ), + ) as mock_well_known, + patch.object( + manager, + "_fetch_authorization_server_metadata", + AsyncMock(return_value=mock_metadata), + ) as mock_fetch_auth, + ): + result = await manager._descovery_metadata("http://localhost:8001/mcp") + + mock_well_known.assert_awaited_once_with("http://localhost:8001/mcp") + mock_fetch_auth.assert_awaited_once_with( + ["https://login.microsoftonline.com/test-tenant-id/v2.0"] + ) + assert result is mock_metadata + assert result.scopes == ["api://some-scope/.default"] + + @pytest.mark.asyncio + async def test_fetch_single_authorization_server_metadata_supports_azure_issuer_path( + self, + ): + manager = MCPServerManager() + issuer = "https://login.microsoftonline.com/test-tenant-id/v2.0" + + def build_response(url: str): + mock_response = MagicMock() + if url == f"{issuer}/.well-known/openid-configuration": + mock_response.json.return_value = { + "authorization_endpoint": "https://login.microsoftonline.com/test-tenant-id/oauth2/v2.0/authorize", + "token_endpoint": "https://login.microsoftonline.com/test-tenant-id/oauth2/v2.0/token", + "scopes_supported": ["api://some-scope/.default"], + } + mock_response.raise_for_status = MagicMock() + else: + request = httpx.Request("GET", url) + response_obj = httpx.Response(status_code=404, request=request) + mock_response.raise_for_status = MagicMock( + side_effect=httpx.HTTPStatusError( + "not found", request=request, response=response_obj + ) + ) + return mock_response + + mock_client = MagicMock() + mock_client.get = AsyncMock(side_effect=build_response) + + with patch( + "litellm.proxy._experimental.mcp_server.mcp_server_manager.get_async_httpx_client", + return_value=mock_client, + ): + result = await manager._fetch_single_authorization_server_metadata(issuer) + + assert result is not None + assert ( + result.authorization_url + == "https://login.microsoftonline.com/test-tenant-id/oauth2/v2.0/authorize" + ) + assert ( + result.token_url + == "https://login.microsoftonline.com/test-tenant-id/oauth2/v2.0/token" + ) + assert result.scopes == ["api://some-scope/.default"] + + @pytest.mark.asyncio + async def test_fetch_single_authorization_server_metadata_derives_azure_metadata( + self, + ): + manager = MCPServerManager() + issuer = "https://login.microsoftonline.com/test-tenant-id/v2.0" + + request = httpx.Request("GET", issuer) + response_obj = httpx.Response(status_code=404, request=request) + mock_response = MagicMock() + mock_response.raise_for_status = MagicMock( + side_effect=httpx.HTTPStatusError( + "not found", request=request, response=response_obj + ) + ) + + mock_client = MagicMock() + mock_client.get = AsyncMock(return_value=mock_response) + + with patch( + "litellm.proxy._experimental.mcp_server.mcp_server_manager.get_async_httpx_client", + return_value=mock_client, + ): + result = await manager._fetch_single_authorization_server_metadata(issuer) + + assert result is not None + assert ( + result.authorization_url + == "https://login.microsoftonline.com/test-tenant-id/oauth2/v2.0/authorize" + ) + assert ( + result.token_url + == "https://login.microsoftonline.com/test-tenant-id/oauth2/v2.0/token" + ) + @pytest.mark.asyncio async def test_descovery_metadata_falls_back_to_origin_when_no_auth_servers(self): manager = MCPServerManager() From 6c5b50135e15ac8db244e6eb63b61688e00b3d37 Mon Sep 17 00:00:00 2001 From: Sameer Kankute Date: Mon, 27 Apr 2026 18:57:22 +0530 Subject: [PATCH 2/3] Fix greptile review --- .../mcp_server/mcp_server_manager.py | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py b/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py index 6aaf37c91ec..edc9c87cdaf 100644 --- a/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py +++ b/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py @@ -106,6 +106,12 @@ if not _separator_probe.is_valid: SEP_986_URL, ) +_AZURE_ENTRA_HOSTS = { + "login.microsoftonline.com", # Global + "login.microsoftonline.us", # US Government + "login.chinacloudapi.cn", # China +} + def _warn_on_server_name_fields( *, @@ -1495,6 +1501,16 @@ class MCPServerManager: metadata = await self._fetch_authorization_server_metadata( authorization_servers ) + if ( + metadata is None + and not resource_scopes + and authorization_servers + and response.status_code == 200 + ): + verbose_logger.warning( + "MCP OAuth discovery for %s received 200 OK without RFC 9728 challenge and no discoverable authorization metadata.", + server_url, + ) if metadata is None and resource_scopes: return MCPOAuthMetadata(scopes=resource_scopes) if metadata is not None and resource_scopes: @@ -1733,7 +1749,7 @@ class MCPServerManager: part for part in (parsed_issuer_url.path or "").split("/") if part ] if ( - parsed_issuer_url.netloc != "login.microsoftonline.com" + parsed_issuer_url.netloc not in _AZURE_ENTRA_HOSTS or len(path_parts) != 2 or path_parts[1] != "v2.0" ): From e0cd536eaa04880b1d142822d6cbb6320cc8ea7f Mon Sep 17 00:00:00 2001 From: Sameer Kankute Date: Wed, 29 Apr 2026 09:06:34 +0530 Subject: [PATCH 3/3] Fix lint --- litellm/proxy/_experimental/mcp_server/mcp_server_manager.py | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py b/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py index edc9c87cdaf..eb0bda3fec2 100644 --- a/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py +++ b/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py @@ -1533,8 +1533,8 @@ class MCPServerManager: header_value ) - authorization_servers: List[str] = [] - resource_scopes: Optional[List[str]] = None + authorization_servers = [] + resource_scopes = None if resource_metadata_url: ( authorization_servers,