chore: import upstream snapshot with attribution

contributing/samples/workflows/request_input/agent.py

@@ -0,0 +1,82 @@
+# 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.
+
+from google.adk import Agent
+from google.adk import Event
+from google.adk import Workflow
+from google.adk.events import RequestInput
+
+
+def process_input(node_input: str):
+  """Takes the initial customer complaint as input and sets it in the state."""
+  yield Event(state={"complaint": node_input, "feedback": ""})
+
+
+draft_email = Agent(
+    name="draft_email",
+    instruction="""
+    Please write a polite, helpful response email to the following customer complaint: "{complaint}"
+
+    If there is any feedback from the manager to revise the draft, please incorporate it: "{feedback?}"
+    """,
+    output_key="draft",
+)
+
+
+def request_human_review(draft: str):
+  yield RequestInput(
+      message=(
+          "Please review the following draft email and provide 'approve',"
+          f" 'reject', or feedback to revise.\n\n---\n{draft}\n---"
+      ),
+  )
+
+
+def handle_human_review(node_input: str):
+  if node_input == "reject":
+    yield Event(route="rejected")
+  elif node_input == "approve":
+    yield Event(route="approved")
+  else:
+    yield Event(state={"feedback": node_input}, route="revise")
+
+
+def reject_email():
+  yield Event(message="Draft rejected.")
+
+
+def send_email(draft: str):
+  yield Event(message="Draft approved and sent successfully.")
+
+
+root_agent = Workflow(
+    name="request_input",
+    edges=[
+        (
+            "START",
+            process_input,
+            draft_email,
+            request_human_review,
+            handle_human_review,
+        ),
+        (
+            handle_human_review,
+            {
+                "revise": draft_email,
+                "approved": send_email,
+                "rejected": reject_email,
+            },
+        ),
+    ],
+)