fix(mcp): Use ProviderName.MCP.value instead of str() for credential provider

Python 3.13 changed str(StrEnum) to return "ClassName.MEMBER" instead of
the plain value. This caused MCP credentials to be stored with provider
"ProviderName.MCP" instead of "mcp", leading to type/provider mismatch
errors during graph validation and execution.

autogpt_platform/backend/backend/api/features/mcp/routes.py

@@ -80,7 +80,7 @@ async def discover_tools(
     if not auth_token:
         try:
             mcp_creds = await creds_manager.store.get_creds_by_provider(
-                user_id, str(ProviderName.MCP)
+                user_id, ProviderName.MCP.value
             )
             # Find the freshest credential for this server URL
             best_cred: OAuth2Credentials | None = None
@@ -250,7 +250,7 @@ async def mcp_oauth_login(
     )
     state_token, code_challenge = await creds_manager.store.store_state_token(
         user_id,
-        str(ProviderName.MCP),
+        ProviderName.MCP.value,
         scopes,
         state_metadata={
             "authorize_url": authorize_url,
@@ -308,7 +308,7 @@ async def mcp_oauth_callback(
     will automatically use the stored credential.
     """
     valid_state = await creds_manager.store.verify_state_token(
-        user_id, request.state_token, str(ProviderName.MCP)
+        user_id, request.state_token, ProviderName.MCP.value
     )
     if not valid_state:
         raise fastapi.HTTPException(
@@ -356,7 +356,7 @@ async def mcp_oauth_callback(
     # Remove old MCP credentials for the same server to prevent stale token buildup
     try:
         old_creds = await creds_manager.store.get_creds_by_provider(
-            user_id, str(ProviderName.MCP)
+            user_id, ProviderName.MCP.value
         )
         for old in old_creds:
             if (

autogpt_platform/backend/backend/blocks/mcp/oauth.py

@@ -113,7 +113,7 @@ class MCPOAuthHandler(BaseOAuthHandler):
         expires_in = tokens.get("expires_in")
 
         return OAuth2Credentials(
-            provider=str(self.PROVIDER_NAME),
+            provider=getattr(self.PROVIDER_NAME, "value", self.PROVIDER_NAME),
             title=None,
             access_token=SecretStr(tokens["access_token"]),
             refresh_token=(
@@ -163,7 +163,7 @@ class MCPOAuthHandler(BaseOAuthHandler):
 
         return OAuth2Credentials(
             id=credentials.id,
-            provider=str(self.PROVIDER_NAME),
+            provider=getattr(self.PROVIDER_NAME, "value", self.PROVIDER_NAME),
             title=credentials.title,
             access_token=SecretStr(tokens["access_token"]),
             refresh_token=(

autogpt_platform/backend/backend/integrations/creds_manager.py

@@ -137,7 +137,7 @@ class IntegrationCredentialsManager:
         self, user_id: str, credentials: OAuth2Credentials, lock: bool = True
     ) -> OAuth2Credentials:
         async with self._locked(user_id, credentials.id, "refresh"):
-            if credentials.provider == str(ProviderName.MCP):
+            if credentials.provider == ProviderName.MCP.value:
                 oauth_handler = _create_mcp_oauth_handler(credentials)
             else:
                 oauth_handler = await _get_provider_oauth_handler(credentials.provider)