fix(mcp): preserve source_url in GET /v1/mcp/server list responses (#29249)

* fix(mcp): preserve source_url in GET /v1/mcp/server list responses

The list endpoint builds responses from the in-memory registry, but
source_url was dropped during the DB-to-registry roundtrip even though
GET /v1/mcp/server/{id} returned it correctly from the database.

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(tests/mcp): set source_url on MagicMock table records

MagicMock auto-creates source_url as a mock object, which fails MCPServer
Pydantic validation after source_url was wired through build_mcp_server_from_table.

Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

litellm/proxy/_experimental/mcp_server/mcp_server_manager.py

@@ -892,6 +892,7 @@ class MCPServerManager:
             is_byok=bool(getattr(mcp_server, "is_byok", False)),
             byok_description=getattr(mcp_server, "byok_description", None) or [],
             byok_api_key_help_url=getattr(mcp_server, "byok_api_key_help_url", None),
+            source_url=getattr(mcp_server, "source_url", None),
             # AWS SigV4 fields
             aws_access_key_id=aws_creds.get("aws_access_key_id"),
             aws_secret_access_key=aws_creds.get("aws_secret_access_key"),
@@ -3750,6 +3751,7 @@ class MCPServerManager:
             is_byok=server.is_byok,
             byok_description=server.byok_description,
             byok_api_key_help_url=server.byok_api_key_help_url,
+            source_url=server.source_url,
             instructions=server.instructions,
         )
 

litellm/types/mcp_server/mcp_server_manager.py

@@ -77,6 +77,7 @@ class MCPServer(BaseModel):
     is_byok: bool = False
     byok_description: List[str] = []
     byok_api_key_help_url: Optional[str] = None
+    source_url: Optional[str] = None
     created_at: Optional[datetime] = None
     updated_at: Optional[datetime] = None
     # OAuth2 flow type.  Defaults to None (interactive / authorization_code).

tests/mcp_tests/test_mcp_server.py

@@ -1505,6 +1505,7 @@ async def test_add_update_server_with_alias():
     mock_mcp_server.created_at = None
     mock_mcp_server.updated_at = None
     mock_mcp_server.instructions = None
+    mock_mcp_server.source_url = None
     mock_mcp_server.approval_status = "active"
 
     # Add server to manager
@@ -1563,6 +1564,7 @@ async def test_add_update_server_without_alias():
     mock_mcp_server.created_at = None
     mock_mcp_server.updated_at = None
     mock_mcp_server.instructions = None
+    mock_mcp_server.source_url = None
     mock_mcp_server.approval_status = "active"
 
     # Add server to manager
@@ -1622,6 +1624,7 @@ async def test_add_update_server_fallback_to_server_id():
     mock_mcp_server.created_at = None
     mock_mcp_server.updated_at = None
     mock_mcp_server.instructions = None
+    mock_mcp_server.source_url = None
     mock_mcp_server.approval_status = "active"
     # Add server to manager
     await test_manager.add_server(mock_mcp_server)

tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_server_manager.py

@@ -2888,6 +2888,31 @@ class TestMCPServerTimestamps:
         assert rebuilt_table.created_at == created
         assert rebuilt_table.updated_at == updated
 
+    @pytest.mark.asyncio
+    async def test_round_trip_source_url_preserved(self):
+        """source_url survives the full round-trip: LiteLLM_MCPServerTable -> MCPServer -> LiteLLM_MCPServerTable.
+
+        Regression test: the list endpoint (GET /v1/mcp/server) builds its
+        response from the registry via this round-trip, so a dropped field
+        here surfaces as a null source_url in the list response even though
+        the value is stored in the DB.
+        """
+        manager = MCPServerManager()
+
+        table_record = LiteLLM_MCPServerTable(
+            server_id="src-url-server",
+            server_name="src_url_server",
+            url="https://example.com/mcp",
+            transport=MCPTransport.http,
+            source_url="https://github.com/org/mcp-server",
+        )
+
+        mcp_server = await manager.build_mcp_server_from_table(table_record)
+        assert mcp_server.source_url == "https://github.com/org/mcp-server"
+
+        rebuilt_table = manager._build_mcp_server_table(mcp_server)
+        assert rebuilt_table.source_url == "https://github.com/org/mcp-server"
+
 
 class TestInternalDelegatePkceWarningLog:
     @pytest.mark.asyncio

tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_sigv4_auth.py

@@ -857,6 +857,7 @@ class TestSigV4BuildFromTable:
         table_record.byok_api_key_help_url = None
         table_record.oauth2_flow = None
         table_record.instructions = None
+        table_record.source_url = None
 
         manager = MCPServerManager()
 
@@ -915,6 +916,7 @@ class TestSigV4BuildFromTable:
         table_record.byok_api_key_help_url = None
         table_record.oauth2_flow = None
         table_record.instructions = None
+        table_record.source_url = None
 
         manager = MCPServerManager()