feat: Sync from internal staging.

.github/dependabot.yml

@@ -1,3 +1,16 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 version: 2
 updates:
   - package-ecosystem: "npm"
@@ -20,4 +33,4 @@ updates:
       interval: "weekly"
     open-pull-requests-limit: 0
     cooldown:
-      default-days: 7
+      default-days: 7

.github/workflows/zizmor.yml

@@ -23,4 +23,4 @@ jobs:
           persist-credentials: false
 
       - name: Run zizmor
-        uses: zizmorcore/zizmor-action@195d10ad90f31d8cd6ea1efd6ecc12969ddbe73f # v0.5.1
+        uses: zizmorcore/zizmor-action@195d10ad90f31d8cd6ea1efd6ecc12969ddbe73f # v0.5.1

agent/python/__main__.py

@@ -18,15 +18,17 @@
 from a2a.server.apps import A2AStarletteApplication
 from a2a.server.request_handlers import DefaultRequestHandler
 from a2a.server.tasks import InMemoryTaskStore
-from a2a.types import AgentCapabilities, AgentCard, AgentSkill
 import click
 import dotenv
 from starlette.middleware.cors import CORSMiddleware
 from starlette.responses import RedirectResponse
 from starlette.staticfiles import StaticFiles
+import uvicorn
 
 from python_agent.agent import MAUIAgent
+from python_agent.agent_config import AgentConfig, FallbackMode
 from python_agent.agent_with_grounding import MAUIAgentWithGrounding
+from python_agent.agent_with_templates import MAUIAgentWithTemplates
 from agent_executor import MAUIAgentExecutor
 
 dotenv.load_dotenv()
@@ -43,7 +45,18 @@ class MissingAPIKeyError(Exception):
 @click.option("--serverurl", default="")
 @click.option("--host", default="0.0.0.0")
 @click.option("--port", default=10002)
-def main(serverurl, host, port):
+@click.option(
+    "--agent",
+    default="MAUIAgent",
+    show_default=True,
+    envvar="A2UI_DEFAULT_AGENT",
+    help=(
+        "Agent to use as default. Accepts class name (e.g., 'MAUIAgent',"
+        " 'MAUIAgentWithTemplates', 'MAUIAgentWithGrounding') or shorthand"
+        " ('BASE', 'TEMPLATE', 'GROUNDING')."
+    ),
+)
+def main(serverurl, host, port, agent):
   try:
     # Check for API key only if Vertex AI is not configured
     if not os.getenv("GOOGLE_GENAI_USE_VERTEXAI") == "TRUE":
@@ -58,21 +71,51 @@ def main(serverurl, host, port):
     if serverurl != "":
       base_url = serverurl
 
+    fallback_mode_env = os.getenv("A2UI_FALLBACK_MODE")
+    if fallback_mode_env:
+      config = AgentConfig(fallback_mode=FallbackMode(fallback_mode_env))
+    else:
+      config = AgentConfig()
+    logger.info(f"Using fallback_mode: {config.fallback_mode}")
+
     ui_agent = MAUIAgent(base_url=base_url)
     grounding_agent = MAUIAgentWithGrounding(base_url=base_url)
+    template_agent = MAUIAgentWithTemplates(base_url=base_url, config=config)
+
+    agent_map = {
+        "MAUIAGENT": ui_agent,
+        "BASE": ui_agent,
+        "MAUIAGENTWITHGROUNDING": grounding_agent,
+        "GROUNDING": grounding_agent,
+        "MAUIAGENTWITHTEMPLATES": template_agent,
+        "TEMPLATE": template_agent,
+    }
+
+    normalized_agent = agent.upper()
+    if normalized_agent not in agent_map:
+      raise ValueError(
+          f"Unknown agent: {agent}. Expected one of {list(agent_map.keys())}"
+      )
+
+    default_agent = agent_map[normalized_agent]
+    logger.info(
+        f"--- SERVER: Binding {default_agent.__class__.__name__} as default"
+        " agent ---"
+    )
 
     agent_executor = MAUIAgentExecutor(
-        default_agent=ui_agent, grounding_agent=grounding_agent
+        default_agent=default_agent,
+        grounding_agent=grounding_agent,
+        template_agent=template_agent,
     )
 
     request_handler = DefaultRequestHandler(
         agent_executor=agent_executor,
         task_store=InMemoryTaskStore(),
     )
     server = A2AStarletteApplication(
-        agent_card=ui_agent.agent_card, http_handler=request_handler
+        agent_card=default_agent.agent_card, http_handler=request_handler
     )
-    import uvicorn
 
     app = server.build()
 

agent/python/agent_executor.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import logging
+from typing import Optional
 
 from a2a.server.agent_execution import AgentExecutor, RequestContext
 from a2a.server.events import EventQueue
@@ -35,6 +36,7 @@
 from a2ui.a2a.extension import try_activate_a2ui_extension
 from python_agent.agent import MAUIAgent
 from python_agent.agent_with_grounding import MAUIAgentWithGrounding
+from python_agent.agent_with_templates import MAUIAgentWithTemplates
 
 logger = logging.getLogger(__name__)
 
@@ -43,10 +45,14 @@ class MAUIAgentExecutor(AgentExecutor):
   """MAUI AgentExecutor Example."""
 
   def __init__(
-      self, default_agent: MAUIAgent, grounding_agent: MAUIAgentWithGrounding
+      self,
+      default_agent: MAUIAgent,
+      grounding_agent: MAUIAgentWithGrounding,
+      template_agent: Optional[MAUIAgentWithTemplates] = None,
   ):
     self._default_agent = default_agent
     self._grounding_agent = grounding_agent
+    self._template_agent = template_agent
 
   async def execute(
       self,
@@ -95,6 +101,15 @@ async def execute(
       )
       agent_to_use = self._grounding_agent
       query = query[len("[GROUNDING]") :].strip()
+    elif query.startswith("[TEMPLATE]"):
+      if not self._template_agent:
+        raise UnsupportedOperationError("Template Agent is not configured.")
+      logger.info(
+          "--- AGENT_EXECUTOR: Prefix [TEMPLATE] detected. Using Template"
+          " Agent. ---"
+      )
+      agent_to_use = self._template_agent
+      query = query[len("[TEMPLATE]") :].strip()
     else:
       logger.info(
           "--- AGENT_EXECUTOR: No prefix detected. Using Default Agent. ---"

client/android/app/src/main/java/com/example/maui/AgentType.kt

@@ -0,0 +1,23 @@
+//
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package com.example.maui
+
+enum class AgentType {
+  LITE,
+  VERTEX,
+  TEMPLATE,
+}

client/android/app/src/main/java/com/example/maui/MainActivity.kt

@@ -128,13 +128,19 @@ class MainActivity : AppCompatActivity() {
     buttonSend.setOnClickListener {
       val messageText = editTextMessage.text.toString().trim()
       if (messageText.isNotEmpty()) {
-        val radioGroundingVertex =
-          findViewById<android.widget.RadioButton>(R.id.radioGroundingVertex)
-        viewModel.sendMessage(
-          messageText,
-          radioGroundingVertex.isChecked,
-          switchCannedServer.isChecked,
-        )
+        val radioAgentVertex = findViewById<android.widget.RadioButton>(R.id.radioAgentVertex)
+        val radioAgentTemplate = findViewById<android.widget.RadioButton>(R.id.radioAgentTemplate)
+
+        val agentType =
+          if (radioAgentVertex.isChecked) {
+            com.example.maui.AgentType.VERTEX
+          } else if (radioAgentTemplate.isChecked) {
+            com.example.maui.AgentType.TEMPLATE
+          } else {
+            com.example.maui.AgentType.LITE
+          }
+
+        viewModel.sendMessage(messageText, agentType, switchCannedServer.isChecked)
         editTextMessage.text.clear()
       }
     }

client/android/app/src/main/java/com/example/maui/ui/ChatViewModel.kt

@@ -46,11 +46,21 @@ class ChatViewModel(
     resourceLogger.startLogging(viewModelScope)
   }
 
-  fun sendMessage(text: String, isGrounding: Boolean = false, bypassCanned: Boolean = false) {
+  fun sendMessage(
+    text: String,
+    agentType: com.example.maui.AgentType = com.example.maui.AgentType.LITE,
+    bypassCanned: Boolean = false,
+  ) {
     currentRequestJob?.cancel()
     currentAgentTextIndex = null
     currentAgentA2UIIndex = null
-    val serverMessageText = if (isGrounding) "[GROUNDING] $text" else text
+    val serverMessageText =
+      when (agentType) {
+        com.example.maui.AgentType.VERTEX -> "[GROUNDING] $text"
+        com.example.maui.AgentType.TEMPLATE -> "[TEMPLATE] $text"
+        com.example.maui.AgentType.LITE -> text
+      }
+
     addMessage(ChatMessage.Text(text, true))
     val jsonObject =
       JSONObject().apply {

client/android/app/src/main/res/layout/activity_main.xml

@@ -34,7 +34,7 @@
         android:id="@+id/promptsLayout"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:layout_above="@+id/groundingRadioGroup"
+        android:layout_above="@+id/agentRadioGroup"
         android:orientation="horizontal"
         android:gravity="center_vertical"
         android:padding="8dp">
@@ -53,7 +53,7 @@
     </LinearLayout>
 
     <RadioGroup
-        android:id="@+id/groundingRadioGroup"
+        android:id="@+id/agentRadioGroup"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_above="@+id/inputLayout"
@@ -63,17 +63,23 @@
         android:background="?android:attr/windowBackground">
 
         <RadioButton
-            android:id="@+id/radioGroundingLite"
+            android:id="@+id/radioAgentLite"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="Grounding Lite (MCP)"
             android:checked="true" />
 
         <RadioButton
-            android:id="@+id/radioGroundingVertex"
+            android:id="@+id/radioAgentVertex"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="Grounding with Google Maps (Vertex)" />
+
+        <RadioButton
+            android:id="@+id/radioAgentTemplate"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="Template Agent" />
     </RadioGroup>
 
     <LinearLayout

client/ios/ChatService.swift

@@ -18,9 +18,10 @@ import Foundation
 import GoogleMapsA2UI
 
 protocol ChatServiceProtocol {
-  func sendMessage(text: String, isVertex: Bool) async throws -> AsyncThrowingStream<
-    ParsedA2AEvent, Swift.Error
-  >
+  func sendMessage(text: String, agentType: AgentType) async throws
+    -> AsyncThrowingStream<
+      ParsedA2AEvent, Swift.Error
+    >
   func sendAction(jsonString: String) async throws -> AsyncThrowingStream<
     ParsedA2AEvent, Swift.Error
   >
@@ -67,12 +68,19 @@ actor ChatService: ChatServiceProtocol {
   private var useSSEProtocol = false
   private let contextID = UUID().uuidString
 
-  func sendMessage(text: String, isVertex: Bool) async throws -> AsyncThrowingStream<
-    ParsedA2AEvent, Swift.Error
-  > {
+  func sendMessage(text: String, agentType: AgentType) async throws
+    -> AsyncThrowingStream<
+      ParsedA2AEvent, Swift.Error
+    >
+  {
     var serverText = text
-    if isVertex {
+    switch agentType {
+    case .vertex:
       serverText = "[GROUNDING] \(text)"
+    case .template:
+      serverText = "[TEMPLATE] \(text)"
+    case .lite:
+      break
     }
     let payload: [String: Any] = ["text": serverText]
     return try await callPythonServer(userMessage: payload)

client/ios/ChatView.swift

@@ -85,7 +85,7 @@ struct ChatView: View {
         }
       }
 
-      GroundingSelector(selection: $viewModel.selectedGroundingType)
+      AgentSelector(selection: $viewModel.selectedAgentType)
 
       Divider()
 
@@ -212,12 +212,12 @@ struct LoadingBubble: View {
   }
 }
 
-struct GroundingSelector: View {
-  @Binding var selection: GroundingType
+struct AgentSelector: View {
+  @Binding var selection: AgentType
 
   var body: some View {
     VStack(alignment: .leading, spacing: 12) {
-      ForEach(GroundingType.allCases) { type in
+      ForEach(AgentType.allCases) { type in
         Button(action: {
           withAnimation(.spring(response: 0.3, dampingFraction: 0.7)) {
             selection = type

client/ios/ChatViewModel.swift

@@ -24,7 +24,7 @@ class ChatViewModel: ObservableObject {
   @Published private(set) var messages: [ChatMessage] = []
   @Published private(set) var isLoading: Bool = false
   @Published var webViewToScrollID: UUID?
-  @Published var selectedGroundingType: GroundingType = .lite
+  @Published var selectedAgentType: AgentType = .lite
 
   private let chatService: ChatServiceProtocol
   private let googleMapsApiKey = "$GOOGLE_MAPS_API_KEY"
@@ -39,13 +39,14 @@ class ChatViewModel: ObservableObject {
 
   /// Sends a text message to the server.
   func sendMessage(text: String) {
-    let isVertex = (selectedGroundingType == .vertex)
+    let agentType = selectedAgentType
     addMessage(.text(content: text, isUser: true))
 
     Task {
       isLoading = true
       do {
-        let stream = try await chatService.sendMessage(text: text, isVertex: isVertex)
+        let stream = try await chatService.sendMessage(
+          text: text, agentType: agentType)
         for try await part in stream {
           handleParsedEvent(part)
         }

client/ios/Models.swift

@@ -17,9 +17,10 @@
 import Foundation
 import SwiftUI
 
-enum GroundingType: String, CaseIterable, Identifiable {
+enum AgentType: String, CaseIterable, Identifiable {
   case lite = "Grounding Lite (MCP)"
   case vertex = "Grounding with Google Maps (Vertex)"
+  case template = "Template Agent"
 
   var id: Self { self }
 }