routes/chat.py

@@ -144,13 +144,16 @@ async def enhanced_generate_stream_response(
                     elif isinstance(msg, ToolMessage) and msg.content:
                         message_tag = "TOOL_RESPONSE"
                         waiting_for_answer_first_char = False
-                        # Always output UIResource responses even when tool_response is disabled
+                        # Always output UIResource, ask_user and render_ui responses even when tool_response is disabled
                         is_ui_resource = (
                             msg.text
                             and msg.text.lstrip().startswith('{"')
                             and '"ui://' in msg.text
+                            and ('"text/html' in msg.text or '"text/uri-list' in msg.text)
                         )
-                        if config.tool_response or is_ui_resource:
+                        is_ask_user = msg.name == 'ask_user'
+                        is_render_ui = msg.name == 'render_ui'
+                        if config.tool_response or is_ui_resource or is_ask_user or is_render_ui:
                             new_content = f"[{message_tag}] {msg.name}\n{msg.text}\n"
 
                     # Collect full content

skills/common/mcp-ui/ui_render_server.py

@@ -8,8 +8,6 @@ import json
 import sys
 from typing import Any, Dict
 
-from mcp_ui_server import create_ui_resource, UIMetadataKey
-
 from mcp_common import (
     create_error_response,
     create_initialize_response,
@@ -20,65 +18,40 @@ from mcp_common import (
 )
 
 
-def _serialize_ui_resource(ui_resource) -> str:
-    """Serialize a UIResource to JSON string."""
-    return json.dumps(ui_resource.model_dump(mode="json"), ensure_ascii=False)
+ASK_USER_RESPONSE = "Questions sent to user."
 
 
 def ask_user() -> Dict[str, Any]:
-    """Return a UIResource response for ask_user tool.
+    """Return a minimal fixed response for ask_user tool.
 
-    The actual questions are in the TOOL_CALL arguments. The frontend
-    detects ui_type from the UIResource metadata and extracts content
-    from the corresponding TOOL_CALL args.
+    The actual questions/options are already in the TOOL_CALL arguments,
+    so the frontend parses them directly from there. This response only
+    serves to acknowledge the tool call and minimize token usage in the
+    subsequent LLM inference round.
     """
-    resource = create_ui_resource({
-        "uri": "ui://mcp-ui/ask-user",
-        "content": {"type": "rawHtml", "htmlString": "Questions sent to user."},
-        "encoding": "text",
-        "uiMetadata": {
-            "type": "ask_user",
-            "interactive": True,
-        },
-    })
-    return {"content": [{"type": "text", "text": _serialize_ui_resource(resource)}]}
+    return {
+        "content": [
+            {"type": "text", "text": ASK_USER_RESPONSE}
+        ]
+    }
 
 
-def render_ui(arguments: Dict[str, Any]) -> Dict[str, Any]:
-    """Return a UIResource response for render_ui tool.
+RENDER_UI_RESPONSE = "UI rendered."
 
-    The actual html_content/url is in the TOOL_CALL arguments. The frontend
-    detects ui_type from the UIResource metadata and extracts content
-    from the corresponding TOOL_CALL args.
+
+def render_ui() -> Dict[str, Any]:
+    """Return a minimal fixed response for render_ui tool.
+
+    The actual html_content/url is already in the TOOL_CALL arguments,
+    so the frontend parses them directly from there. This response only
+    serves to acknowledge the tool call and minimize token usage in the
+    subsequent LLM inference round.
     """
-    html_content = arguments.get("html_content", "")
-    url = arguments.get("url", "")
-    width = arguments.get("width", "100%")
-    height = arguments.get("height", "auto")
-
-    if html_content:
-        resource = create_ui_resource({
-            "uri": "ui://mcp-ui/render-ui",
-            "content": {"type": "rawHtml", "htmlString": "UI rendered."},
-            "encoding": "text",
-            "uiMetadata": {
-                UIMetadataKey.PREFERRED_FRAME_SIZE: [width, height],
-                "type": "render_ui_html",
-                "interactive": False,
-            },
-        })
-    else:
-        resource = create_ui_resource({
-            "uri": "ui://mcp-ui/render-ui",
-            "content": {"type": "externalUrl", "iframeUrl": url},
-            "encoding": "text",
-            "uiMetadata": {
-                UIMetadataKey.PREFERRED_FRAME_SIZE: [width, height],
-                "type": "render_ui_url",
-                "interactive": False,
-            },
-        })
-    return {"content": [{"type": "text", "text": _serialize_ui_resource(resource)}]}
+    return {
+        "content": [
+            {"type": "text", "text": RENDER_UI_RESPONSE}
+        ]
+    }
 
 
 async def handle_request(request: Dict[str, Any]) -> Dict[str, Any]:
@@ -136,7 +109,7 @@ async def handle_request(request: Dict[str, Any]) -> Dict[str, Any]:
                         request_id, -32602, "Missing required parameter: html_content or url"
                     )
 
-                result = render_ui(arguments)
+                result = render_ui()
                 return {"jsonrpc": "2.0", "id": request_id, "result": result}
 
             elif tool_name == "ask_user":