diff --git a/litellm/__init__.py b/litellm/__init__.py
index d75f47567a5..cf71502b8a9 100644
--- a/litellm/__init__.py
+++ b/litellm/__init__.py
@@ -160,6 +160,11 @@ langfuse_default_tags: Optional[List[str]] = None
 langsmith_batch_size: Optional[int] = None
 prometheus_initialize_budget_metrics: Optional[bool] = False
 require_auth_for_metrics_endpoint: Optional[bool] = False
+# When True (default), BYOK MCP servers raise HTTP 503 if the credential store
+# (Prisma DB) is unavailable, rather than silently bypassing the BYOK check.
+# Set to False to restore pre-v1.x legacy behaviour for stateless deployments
+# that do not use a database.
+require_byok_credential_store: Optional[bool] = True
 argilla_batch_size: Optional[int] = None
 datadog_use_v1: Optional[bool] = False  # if you want to use v1 datadog logged payload.
 gcs_pub_sub_use_v1: Optional[bool] = (
diff --git a/litellm/proxy/_experimental/mcp_server/server.py b/litellm/proxy/_experimental/mcp_server/server.py
index 9f3b8196244..5fb011f5148 100644
--- a/litellm/proxy/_experimental/mcp_server/server.py
+++ b/litellm/proxy/_experimental/mcp_server/server.py
@@ -28,6 +28,7 @@ from starlette.requests import Request as StarletteRequest
 from starlette.responses import JSONResponse
 from starlette.types import Receive, Scope, Send
 
+import litellm
 from litellm._logging import verbose_logger
 from litellm.constants import MAXIMUM_TRACEBACK_LINES_TO_LOG
 from litellm.litellm_core_utils.litellm_logging import Logging as LiteLLMLoggingObj
@@ -1586,16 +1587,21 @@ if MCP_AVAILABLE:
 
         if prisma_client is None:
             # Without a database we cannot fetch the per-user credential.
-            # Return a 503 (infrastructure problem) so callers can distinguish
-            # "no credential" (401) from "credential store unavailable" (503).
-            raise HTTPException(
-                status_code=503,
-                detail={
-                    "error": "byok_store_unavailable",
-                    "server_id": mcp_server.server_id,
-                    "message": "Credential store is not available; cannot fetch BYOK credential.",
-                },
-            )
+            # When require_byok_credential_store is True (default) we raise 503
+            # so callers can distinguish "no credential" (401) from
+            # "credential store unavailable" (503).
+            # Set litellm.require_byok_credential_store = False to restore the
+            # legacy silent-bypass behaviour for stateless deployments.
+            if litellm.require_byok_credential_store:
+                raise HTTPException(
+                    status_code=503,
+                    detail={
+                        "error": "byok_store_unavailable",
+                        "server_id": mcp_server.server_id,
+                        "message": "Credential store is not available; cannot fetch BYOK credential.",
+                    },
+                )
+            return None
         raw = await get_user_credential(
             prisma_client=prisma_client,
             user_id=user_id,
@@ -1666,17 +1672,20 @@ if MCP_AVAILABLE:
 
         if prisma_client is None:
             # Without a database we cannot verify whether the user has a stored
-            # credential, so we must deny access rather than silently bypass the
-            # BYOK check.  A 503 signals a configuration/infrastructure problem,
-            # not an auth failure, so clients can distinguish the two cases.
-            raise HTTPException(
-                status_code=503,
-                detail={
-                    "error": "byok_store_unavailable",
-                    "server_id": mcp_server.server_id,
-                    "message": "Credential store is not available; cannot verify BYOK access.",
-                },
-            )
+            # credential.  When require_byok_credential_store is True (default)
+            # we raise 503 to distinguish infra failures from missing credentials.
+            # Set litellm.require_byok_credential_store = False to restore the
+            # legacy silent-bypass behaviour for stateless deployments.
+            if litellm.require_byok_credential_store:
+                raise HTTPException(
+                    status_code=503,
+                    detail={
+                        "error": "byok_store_unavailable",
+                        "server_id": mcp_server.server_id,
+                        "message": "Credential store is not available; cannot verify BYOK access.",
+                    },
+                )
+            return
 
         raw_credential = await get_user_credential(
             prisma_client=prisma_client,