From cc6e6deb98c614479ea1433b42bc7ba4eabc9250 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Thu, 4 Jun 2026 02:51:38 +0000
Subject: [PATCH] fix(mcp): convert registry env_vars to MCPEnvVar when
 building server table

MCPServer.env_vars is stored as List[Dict[str, Any]] (deserialized from
the JSON column), but LiteLLM_MCPServerTable.env_vars is typed as
List[MCPEnvVar]. Passing the raw dicts relied on pydantic coercion at
runtime and tripped mypy's dataclass_transform __init__ check, failing
the lint job. Normalize the dicts into MCPEnvVar models at both
construction sites.
---
 .../_experimental/mcp_server/mcp_server_manager.py  | 13 +++++++++++--
 1 file changed, 11 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 b395fc9ed40..38ed6ffd67f 100644
--- a/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py
+++ b/litellm/proxy/_experimental/mcp_server/mcp_server_manager.py
@@ -71,6 +71,7 @@ from litellm.proxy._experimental.mcp_server.utils import (
 from litellm.proxy._types import (
     LiteLLM_MCPServerTable,
     MCPAuthType,
+    MCPEnvVar,
     MCPTransport,
     MCPTransportType,
     UserAPIKeyAuth,
@@ -3957,7 +3958,7 @@ class MCPServerManager:
             extra_headers=server.extra_headers or [],
             mcp_info=server.mcp_info,
             static_headers=server.static_headers,
-            env_vars=server.env_vars,
+            env_vars=self._env_vars_to_models(server.env_vars),
             status=status,
             last_health_check=datetime.now(),
             health_check_error=health_check_error,
@@ -4030,6 +4031,14 @@ class MCPServerManager:
 
         return list_mcp_servers
 
+    @staticmethod
+    def _env_vars_to_models(
+        env_vars: Optional[List[Dict[str, Any]]],
+    ) -> Optional[List[MCPEnvVar]]:
+        if env_vars is None:
+            return None
+        return [MCPEnvVar.model_validate(env_var) for env_var in env_vars]
+
     def _build_mcp_server_table(self, server: MCPServer) -> LiteLLM_MCPServerTable:
         return LiteLLM_MCPServerTable(
             server_id=server.server_id,
@@ -4050,7 +4059,7 @@ class MCPServerManager:
             extra_headers=server.extra_headers or [],
             mcp_info=server.mcp_info,
             static_headers=server.static_headers,
-            env_vars=server.env_vars,
+            env_vars=self._env_vars_to_models(server.env_vars),
             status=None,  # No health check performed
             last_health_check=None,  # No health check performed
             health_check_error=None,