fix(showcase/google-adk): wire AGUIToolset + strip nested-required so gen-UI demos render

Two compounding root causes were silently breaking every generative-UI demo
that depended on frontend-registered tools (useFrontendTool, useComponent,
useHumanInTheLoop):

1) Missing AGUIToolset() in bespoke agents
   The ag_ui_adk middleware injects the frontend's tool registrations by
   *replacing* AGUIToolset instances in the agent's `tools` list with a
   ClientProxyToolset that wraps `input.tools`. If no AGUIToolset is
   present, the frontend tools are dropped silently and the model never
   sees render_bar_chart / render_pie_chart / etc. Bespoke agents (the ones
   built directly with LlmAgent(...) instead of via build_simple_chat_agent
   in shared_chat.py) all had `tools=[]` or `tools=[backend_only]`.
   Appended AGUIToolset() to every bespoke agent.

2) Nested `required` in tool parameter schemas
   Gemini's function-calling API silently rejects function declarations
   whose parameter schema contains a `required` field below the top-level
   object — e.g. on the items.properties of an array, or on a nested
   property's own properties. The Zod-generated schema for render_bar_chart
   has exactly that shape (items.properties with required: [label, value]).
   The model emits no TOOL_CALL_* events, no TEXT_MESSAGE_*, just RUN_STARTED
   → STATE_SNAPSHOT → RUN_FINISHED. ag_ui_adk's _clean_schema_for_genai
   doesn't strip nested required.

   agent_server.py now monkey-patches _clean_schema_for_genai at startup so
   nested `required` is stripped before tool definitions reach the model.
   Top-level required is preserved (Gemini accepts it there). The patch is
   defensive and per-process — no upstream dependency change needed.

Verification: curl test against /gen-ui-tool-based with the LP-shaped tool
schema now emits TOOL_CALL_START + TOOL_CALL_ARGS containing the chart
payload. Browser test renders the bar chart in the chat with Q1/Q2/Q3/Q4
data. Sanity-checked gen-ui-agent (set_steps state-streaming) — fully
working, live "All 3 steps complete" card rendered.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: tylerslaton

showcase/integrations/google-adk/src/agent_server.py

@@ -25,6 +25,7 @@
 import os
 import uvicorn
 from ag_ui_adk import ADKAgent, add_adk_fastapi_endpoint
+import ag_ui_adk.client_proxy_tool as _cpt
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from starlette.middleware.base import BaseHTTPMiddleware
@@ -35,6 +36,64 @@
 
 load_dotenv()
 
+
+# Gemini's function-calling API silently rejects function declarations that
+# carry a `required` field inside nested object schemas (e.g. on
+# `items.properties` of an array, or on properties of an object property).
+# The model emits no TOOL_CALL_* events and no error — it just returns an
+# empty response, which manifests as the agent appearing to hang. Strip
+# `required` from any schema that isn't the top-level parameters object
+# before ag_ui_adk hands the tool definition to genai.
+#
+# Top-level `required` is preserved (Gemini supports it there).
+_original_clean_schema = _cpt._clean_schema_for_genai
+
+
+def _strip_nested_required(schema, _top_level=False):
+    if isinstance(schema, dict):
+        out = {}
+        for k, v in schema.items():
+            if k == "required" and not _top_level:
+                continue
+            if k in ("properties", "defs") and isinstance(v, dict):
+                out[k] = {
+                    pn: _strip_nested_required(ps, _top_level=False)
+                    for pn, ps in v.items()
+                }
+            elif isinstance(v, (dict, list)):
+                out[k] = _strip_nested_required(v, _top_level=False)
+            else:
+                out[k] = v
+        return out
+    if isinstance(schema, list):
+        return [_strip_nested_required(item, _top_level=False) for item in schema]
+    return schema
+
+
+def _patched_clean_schema_for_genai(schema):
+    cleaned = _original_clean_schema(schema)
+    # Walk the cleaned schema and remove `required` everywhere except the
+    # outermost object (which Gemini does accept).
+    if isinstance(cleaned, dict):
+        top = {}
+        for k, v in cleaned.items():
+            if k == "required":
+                top[k] = v  # preserve top-level required
+            elif k in ("properties", "defs") and isinstance(v, dict):
+                top[k] = {
+                    pn: _strip_nested_required(ps, _top_level=False)
+                    for pn, ps in v.items()
+                }
+            elif isinstance(v, (dict, list)):
+                top[k] = _strip_nested_required(v, _top_level=False)
+            else:
+                top[k] = v
+        return top
+    return cleaned
+
+
+_cpt._clean_schema_for_genai = _patched_clean_schema_for_genai
+
 app = FastAPI(title="Google ADK Agent Server")
 
 

showcase/integrations/google-adk/src/agents/a2ui_fixed_agent.py

@@ -12,6 +12,7 @@
 from pathlib import Path
 from typing import Any
 
+from ag_ui_adk import AGUIToolset
 from google.adk.agents import LlmAgent
 from google.adk.tools import ToolContext
 
@@ -98,5 +99,5 @@ def display_flight(
     name="A2uiFixedAgent",
     model=get_model(),
     instruction=_INSTRUCTION,
-    tools=[display_flight],
+    tools=[display_flight, AGUIToolset()],
 )

showcase/integrations/google-adk/src/agents/agent_config_agent.py

@@ -12,6 +12,7 @@
 import logging
 from typing import Optional
 
+from ag_ui_adk import AGUIToolset
 from google.adk.agents import LlmAgent
 from google.adk.agents.callback_context import CallbackContext
 from google.adk.models.llm_request import LlmRequest
@@ -144,6 +145,6 @@ def _inject_config(
     name="AgentConfigAgent",
     model=get_model(),
     instruction=_INSTRUCTION,
-    tools=[],
+    tools=[AGUIToolset()],
     before_model_callback=_inject_config,
 )

showcase/integrations/google-adk/src/agents/beautiful_chat_agent.py

@@ -8,6 +8,7 @@
 
 from __future__ import annotations
 
+from ag_ui_adk import AGUIToolset
 from google.adk.agents import LlmAgent
 from google.adk.tools import ToolContext
 
@@ -49,5 +50,5 @@ def schedule_meeting(
     name="BeautifulChatAgent",
     model=get_model(),
     instruction=_INSTRUCTION,
-    tools=[query_data, search_flights, schedule_meeting],
+    tools=[query_data, search_flights, schedule_meeting, AGUIToolset()],
 )

showcase/integrations/google-adk/src/agents/byoc_agents.py

@@ -8,6 +8,7 @@
 
 from __future__ import annotations
 
+from ag_ui_adk import AGUIToolset
 from google.adk.agents import LlmAgent
 from google.adk.tools import ToolContext
 
@@ -31,5 +32,5 @@ def query_data(tool_context: ToolContext, query: str) -> list:
     name="ByocAgent",
     model=get_model(),
     instruction=_INSTRUCTION,
-    tools=[query_data],
+    tools=[query_data, AGUIToolset()],
 )

showcase/integrations/google-adk/src/agents/declarative_gen_ui_agent.py

@@ -9,6 +9,7 @@
 
 from __future__ import annotations
 
+from ag_ui_adk import AGUIToolset
 from google.adk.agents import LlmAgent
 
 from agents.shared_chat import get_model
@@ -27,5 +28,5 @@
     name="DeclarativeGenUiAgent",
     model=get_model(),
     instruction=_INSTRUCTION,
-    tools=[generate_a2ui],
+    tools=[generate_a2ui, AGUIToolset()],
 )

showcase/integrations/google-adk/src/agents/gen_ui_agent.py

@@ -10,6 +10,7 @@
 
 from __future__ import annotations
 
+from ag_ui_adk import AGUIToolset
 from google.adk.agents import LlmAgent
 from google.adk.tools import ToolContext
 
@@ -55,5 +56,5 @@ def set_steps(tool_context: ToolContext, steps: list[dict]) -> dict:
     name="GenUiAgent",
     model=get_model(),
     instruction=_INSTRUCTION,
-    tools=[set_steps],
+    tools=[set_steps, AGUIToolset()],
 )

showcase/integrations/google-adk/src/agents/gen_ui_tool_based_agent.py

@@ -8,6 +8,7 @@
 from __future__ import annotations
 
 from google.adk.agents import LlmAgent
+from ag_ui_adk import AGUIToolset
 
 from agents.shared_chat import get_model
 
@@ -24,5 +25,5 @@
     name="GenUiToolBasedAgent",
     model=get_model(),
     instruction=_INSTRUCTION,
-    tools=[],
+    tools=[AGUIToolset()],
 )

showcase/integrations/google-adk/src/agents/mcp_apps_agent.py

@@ -13,6 +13,7 @@
 
 from __future__ import annotations
 
+from ag_ui_adk import AGUIToolset
 from google.adk.agents import LlmAgent
 
 from agents.shared_chat import get_model
@@ -55,5 +56,5 @@
     name="McpAppsAgent",
     model=get_model(),
     instruction=_INSTRUCTION,
-    tools=[],
+    tools=[AGUIToolset()],
 )

showcase/integrations/google-adk/src/agents/multimodal_agent.py

@@ -8,6 +8,7 @@
 
 from __future__ import annotations
 
+from ag_ui_adk import AGUIToolset
 from google.adk.agents import LlmAgent
 
 from agents.shared_chat import get_model
@@ -24,5 +25,5 @@
     name="MultimodalAgent",
     model=get_model(),
     instruction=_INSTRUCTION,
-    tools=[],
+    tools=[AGUIToolset()],
 )