fix(frontend/mcp): Remove broken credentials widget and disable auto-connect

- Remove credentials field from MCP dynamic schema since auth is handled
  by the dialog's OAuth flow (the standard credentials widget doesn't
  support MCP as a provider and fails with 404)
- Simplify FormCreator MCP handling — all form fields are tool arguments
- Disable auto-connect on dialog open; pre-fill last URL instead so user
  can edit before connecting

autogpt_platform/frontend/src/app/(platform)/build/components/FlowEditor/nodes/CustomNode/useCustomNode.tsx

@@ -9,30 +9,22 @@ import { SpecialBlockID } from "@/lib/autogpt-server-api";
  * Build a dynamic input schema for MCP blocks.
  *
  * When a tool has been selected (tool_input_schema is populated), the block
- * should render:
- *   1. The credentials field (from the static schema)
- *   2. The selected tool's input parameters (from tool_input_schema)
+ * renders only the selected tool's input parameters. Credentials are NOT
+ * included because authentication is already handled by the MCP dialog's
+ * OAuth flow and stored server-side.
  *
  * Static fields like server_url, selected_tool, available_tools, and
  * tool_arguments are hidden because they're pre-configured from the dialog.
  */
 function buildMCPInputSchema(
-  staticSchema: Record<string, any>,
   toolInputSchema: Record<string, any>,
 ): Record<string, any> {
-  const credentialsProp = staticSchema.properties?.credentials;
-  const staticRequired = staticSchema.required ?? [];
-
   return {
     type: "object",
     properties: {
-      ...(credentialsProp ? { credentials: credentialsProp } : {}),
       ...(toolInputSchema.properties ?? {}),
     },
-    required: [
-      ...staticRequired.filter((r: string) => r === "credentials"),
-      ...(toolInputSchema.required ?? []),
-    ],
+    required: [...(toolInputSchema.required ?? [])],
   };
 }
 
@@ -58,10 +50,7 @@ export const useCustomNode = ({
   const currentInputSchema = isAgent
     ? (data.hardcodedValues.input_schema ?? {})
     : isMCPWithTool
-      ? buildMCPInputSchema(
-          data.inputSchema,
-          data.hardcodedValues.tool_input_schema,
-        )
+      ? buildMCPInputSchema(data.hardcodedValues.tool_input_schema)
       : data.inputSchema;
   const currentOutputSchema = isAgent
     ? (data.hardcodedValues.output_schema ?? {})

autogpt_platform/frontend/src/app/(platform)/build/components/FlowEditor/nodes/FormCreator.tsx

@@ -44,12 +44,10 @@ export const FormCreator: React.FC<FormCreatorProps> = React.memo(
           inputs: formData,
         };
       } else if (isMCPWithTool) {
-        // Separate credentials from tool arguments
-        const { credentials, ...toolArgs } = formData;
+        // All form fields are tool arguments (credentials handled by dialog)
         updatedValues = {
           ...getHardCodedValues(nodeId),
-          ...(credentials ? { credentials } : {}),
-          tool_arguments: toolArgs,
+          tool_arguments: formData,
         };
       } else {
         updatedValues = formData;
@@ -64,13 +62,7 @@ export const FormCreator: React.FC<FormCreatorProps> = React.memo(
     if (isAgent) {
       initialValues = hardcodedValues.inputs ?? {};
     } else if (isMCPWithTool) {
-      // Merge credentials + tool_arguments for the combined schema
-      initialValues = {
-        ...(hardcodedValues.credentials
-          ? { credentials: hardcodedValues.credentials }
-          : {}),
-        ...(hardcodedValues.tool_arguments ?? {}),
-      };
+      initialValues = hardcodedValues.tool_arguments ?? {};
     } else {
       initialValues = hardcodedValues;
     }

autogpt_platform/frontend/src/app/(platform)/build/components/legacy-builder/CustomNode/CustomNode.tsx

@@ -222,20 +222,17 @@ export const CustomNode = React.memo(
       !!data.hardcodedValues?.tool_input_schema?.properties;
 
     if (isMCPWithTool) {
-      const credentialsProp = data.inputSchema?.properties?.credentials;
+      // Show only the tool's input parameters. Credentials are NOT included
+      // because authentication is handled by the MCP dialog's OAuth flow
+      // and stored server-side.
       const toolSchema = data.hardcodedValues.tool_input_schema;
-      const staticRequired = data.inputSchema?.required ?? [];
 
       data.inputSchema = {
         type: "object",
         properties: {
-          ...(credentialsProp ? { credentials: credentialsProp } : {}),
           ...(toolSchema.properties ?? {}),
         },
-        required: [
-          ...staticRequired.filter((r: string) => r === "credentials"),
-          ...(toolSchema.required ?? []),
-        ],
+        required: [...(toolSchema.required ?? [])],
       } as BlockIORootSchema;
     }
 
@@ -562,8 +559,7 @@ export const CustomNode = React.memo(
         default:
           const getInputPropKey = (key: string) => {
             if (nodeType == BlockUIType.AGENT) return `inputs.${key}`;
-            if (isMCPWithTool && key !== "credentials")
-              return `tool_arguments.${key}`;
+            if (isMCPWithTool) return `tool_arguments.${key}`;
             return key;
           };
 

autogpt_platform/frontend/src/app/(platform)/build/components/legacy-builder/MCPToolDialog.tsx

@@ -66,33 +66,21 @@ export function MCPToolDialog({
   const oauthHandledRef = useRef(false);
   const autoConnectAttemptedRef = useRef(false);
 
-  // Attempt auto-connect when dialog opens with a stored server URL
+  // Pre-fill last used server URL when dialog opens (without auto-connecting)
   useEffect(() => {
     if (!open) {
       autoConnectAttemptedRef.current = false;
       return;
     }
 
-    const lastUrl = localStorage.getItem(STORAGE_KEY);
-    if (!lastUrl || autoConnectAttemptedRef.current) return;
+    if (autoConnectAttemptedRef.current) return;
     autoConnectAttemptedRef.current = true;
 
-    setServerUrl(lastUrl);
-    setLoading(true);
-    api
-      .mcpDiscoverTools(lastUrl)
-      .then((result) => {
-        setTools(result.tools);
-        setServerName(result.server_name);
-        setStep("tool");
-      })
-      .catch(() => {
-        // Stored credential expired or server changed — stay on URL step
-      })
-      .finally(() => {
-        setLoading(false);
-      });
-  }, [open, api]);
+    const lastUrl = localStorage.getItem(STORAGE_KEY);
+    if (lastUrl) {
+      setServerUrl(lastUrl);
+    }
+  }, [open]);
 
   // Clean up listeners on unmount
   useEffect(() => {