chore: import upstream snapshot with attribution

contributing/samples/a2a/a2a_basic/agent.py

@@ -0,0 +1,120 @@
+# 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.
+
+import random
+
+from google.adk.agents.llm_agent import Agent
+from google.adk.agents.remote_a2a_agent import AGENT_CARD_WELL_KNOWN_PATH
+from google.adk.agents.remote_a2a_agent import RemoteA2aAgent
+from google.adk.tools.example_tool import ExampleTool
+from google.genai import types
+
+
+# --- Roll Die Sub-Agent ---
+def roll_die(sides: int) -> int:
+  """Roll a die and return the rolled result."""
+  return random.randint(1, sides)
+
+
+roll_agent = Agent(
+    name="roll_agent",
+    description="Handles rolling dice of different sizes.",
+    instruction="""
+      You are responsible for rolling dice based on the user's request.
+      When asked to roll a die, you must call the roll_die tool with the number of sides as an integer.
+    """,
+    tools=[roll_die],
+    generate_content_config=types.GenerateContentConfig(
+        safety_settings=[
+            types.SafetySetting(  # avoid false alarm about rolling dice.
+                category=types.HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT,
+                threshold=types.HarmBlockThreshold.OFF,
+            ),
+        ]
+    ),
+)
+
+
+example_tool = ExampleTool([
+    {
+        "input": {
+            "role": "user",
+            "parts": [{"text": "Roll a 6-sided die."}],
+        },
+        "output": [
+            {"role": "model", "parts": [{"text": "I rolled a 4 for you."}]}
+        ],
+    },
+    {
+        "input": {
+            "role": "user",
+            "parts": [{"text": "Is 7 a prime number?"}],
+        },
+        "output": [{
+            "role": "model",
+            "parts": [{"text": "Yes, 7 is a prime number."}],
+        }],
+    },
+    {
+        "input": {
+            "role": "user",
+            "parts": [{"text": "Roll a 10-sided die and check if it's prime."}],
+        },
+        "output": [
+            {
+                "role": "model",
+                "parts": [{"text": "I rolled an 8 for you."}],
+            },
+            {
+                "role": "model",
+                "parts": [{"text": "8 is not a prime number."}],
+            },
+        ],
+    },
+])
+
+prime_agent = RemoteA2aAgent(
+    name="prime_agent",
+    description="Agent that handles checking if numbers are prime.",
+    agent_card=(
+        f"http://localhost:8001/a2a/check_prime_agent{AGENT_CARD_WELL_KNOWN_PATH}"
+    ),
+)
+
+
+root_agent = Agent(
+    name="root_agent",
+    instruction="""
+      You are a helpful assistant that can roll dice and check if numbers are prime.
+      You delegate rolling dice tasks to the roll_agent and prime checking tasks to the prime_agent.
+      Follow these steps:
+      1. If the user asks to roll a die, delegate to the roll_agent.
+      2. If the user asks to check primes, delegate to the prime_agent.
+      3. If the user asks to roll a die and then check if the result is prime, call roll_agent first, then pass the result to prime_agent.
+      Always clarify the results before proceeding.
+    """,
+    global_instruction=(
+        "You are DicePrimeBot, ready to roll dice and check prime numbers."
+    ),
+    sub_agents=[roll_agent, prime_agent],
+    tools=[example_tool],
+    generate_content_config=types.GenerateContentConfig(
+        safety_settings=[
+            types.SafetySetting(  # avoid false alarm about rolling dice.
+                category=types.HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT,
+                threshold=types.HarmBlockThreshold.OFF,
+            ),
+        ]
+    ),
+)