diff --git a/litellm/proxy/relay_endpoints/endpoints.py b/litellm/proxy/relay_endpoints/endpoints.py
index 1d96ce7ff8b..76c32201c6b 100644
--- a/litellm/proxy/relay_endpoints/endpoints.py
+++ b/litellm/proxy/relay_endpoints/endpoints.py
@@ -3,6 +3,7 @@ from pathlib import Path
 
 import yaml
 from fastapi import APIRouter, Depends, HTTPException
+from pydantic import ValidationError
 
 from litellm.proxy.auth.user_api_key_auth import user_api_key_auth
 from litellm.types.proxy.relay_endpoints import RelayManagedConfigResponse
@@ -26,7 +27,7 @@ def _load_managed_config(path: Path) -> RelayManagedConfigResponse:
     except yaml.YAMLError as e:
         raise HTTPException(
             status_code=500,
-            detail={"error": f"Failed to parse Relay settings at {path}: {e}"},
+            detail={"error": f"Failed to parse Relay settings ({RELAY_SETTINGS_PATH_ENV}): {e}"},
         )
 
     if parsed is None:
@@ -34,9 +35,17 @@ def _load_managed_config(path: Path) -> RelayManagedConfigResponse:
     if not isinstance(parsed, dict):
         raise HTTPException(
             status_code=500,
-            detail={"error": f"Relay settings at {path} must be a YAML mapping, got {type(parsed).__name__}"},
+            detail={
+                "error": f"Relay settings ({RELAY_SETTINGS_PATH_ENV}) must be a YAML mapping, got {type(parsed).__name__}"
+            },
+        )
+    try:
+        return RelayManagedConfigResponse.model_validate(parsed)
+    except ValidationError as e:
+        raise HTTPException(
+            status_code=500,
+            detail={"error": f"Relay settings ({RELAY_SETTINGS_PATH_ENV}) failed schema validation: {e}"},
         )
-    return RelayManagedConfigResponse.model_validate(parsed)
 
 
 @router.get(
diff --git a/litellm/types/proxy/relay_endpoints.py b/litellm/types/proxy/relay_endpoints.py
index 169db8e3afd..f6007c150d4 100644
--- a/litellm/types/proxy/relay_endpoints.py
+++ b/litellm/types/proxy/relay_endpoints.py
@@ -1,28 +1,26 @@
-from typing import Dict, Optional
-
 from pydantic import BaseModel, Field, JsonValue
 
 
 class RelayClaudeCodeConfig(BaseModel):
     channel: str = Field(default="pinned")
-    version: Optional[str] = Field(default=None)
+    version: str | None = Field(default=None)
     registry: str = Field(default="npm")
     package: str = Field(default="@anthropic-ai/claude-code")
-    model: Optional[str] = Field(default=None)
-    managed_settings: Dict[str, JsonValue] = Field(default_factory=dict)
+    model: str | None = Field(default=None)
+    managed_settings: dict[str, JsonValue] = Field(default_factory=dict)
 
 
 class RelayCodexConfig(BaseModel):
     channel: str = Field(default="pinned")
-    version: Optional[str] = Field(default=None)
+    version: str | None = Field(default=None)
     registry: str = Field(default="npm")
     package: str = Field(default="@openai/codex")
-    model: Optional[str] = Field(default=None)
+    model: str | None = Field(default=None)
 
 
 class RelayManagedConfigResponse(BaseModel):
     claude_code: RelayClaudeCodeConfig = Field(default_factory=RelayClaudeCodeConfig)
     codex: RelayCodexConfig = Field(default_factory=RelayCodexConfig)
-    policy_version: Optional[int] = Field(default=None)
-    updated_by: Optional[str] = Field(default=None)
-    updated_at: Optional[str] = Field(default=None)
+    policy_version: int | None = Field(default=None)
+    updated_by: str | None = Field(default=None)
+    updated_at: str | None = Field(default=None)
diff --git a/tests/test_litellm/proxy/relay_endpoints/test_endpoints.py b/tests/test_litellm/proxy/relay_endpoints/test_endpoints.py
index 446ba260471..a3dfead25b6 100644
--- a/tests/test_litellm/proxy/relay_endpoints/test_endpoints.py
+++ b/tests/test_litellm/proxy/relay_endpoints/test_endpoints.py
@@ -109,6 +109,16 @@ def test_load_managed_config_rejects_invalid_yaml(tmp_path: Path) -> None:
     assert exc_info.value.status_code == 500
 
 
+def test_load_managed_config_rejects_wrong_field_type(tmp_path: Path) -> None:
+    path = tmp_path / "relay_settings.yaml"
+    path.write_text("policy_version: not-an-integer\n")
+
+    with pytest.raises(HTTPException) as exc_info:
+        _load_managed_config(path)
+
+    assert exc_info.value.status_code == 500
+
+
 def test_load_managed_config_preserves_nested_managed_settings(tmp_path: Path) -> None:
     path = tmp_path / "relay_settings.yaml"
     path.write_text(