docs(config): add examples for config agents

PiperOrigin-RevId: 793871778

contributing/samples/core_custom_agent/my_agents.py

@@ -0,0 +1,57 @@
+from __future__ import annotations
+
+from keyword import kwlist
+from typing import Any
+from typing import AsyncGenerator
+from typing import ClassVar
+from typing import Dict
+from typing import Type
+
+from google.adk.agents import BaseAgent
+from google.adk.agents.base_agent_config import BaseAgentConfig
+from google.adk.agents.invocation_context import InvocationContext
+from google.adk.events.event import Event
+from google.genai import types
+from pydantic import ConfigDict
+from typing_extensions import override
+
+
+class MyCustomAgentConfig(BaseAgentConfig):
+  model_config = ConfigDict(
+      extra="forbid",
+  )
+  agent_class: str = "core_cutom_agent.my_agents.MyCustomAgent"
+  my_field: str = ""
+
+
+class MyCustomAgent(BaseAgent):
+  my_field: str = ""
+
+  config_type: ClassVar[type[BaseAgentConfig]] = MyCustomAgentConfig
+
+  @override
+  @classmethod
+  def _parse_config(
+      cls: Type[MyCustomAgent],
+      config: MyCustomAgentConfig,
+      config_abs_path: str,
+      kwargs: Dict[str, Any],
+  ) -> Dict[str, Any]:
+    if config.my_field:
+      kwargs["my_field"] = config.my_field
+    return kwargs
+
+  async def _run_async_impl(
+      self, ctx: InvocationContext
+  ) -> AsyncGenerator[Event, None]:
+    yield Event(
+        invocation_id=ctx.invocation_id,
+        author=self.name,
+        content=types.ModelContent(
+            parts=[
+                types.Part(
+                    text=f"I feel good! value in my_field: `{self.my_field}`"
+                )
+            ]
+        ),
+    )

contributing/samples/core_custom_agent/root_agent.yaml

@@ -0,0 +1,5 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/google/adk-python/refs/heads/main/src/google/adk/agents/config_schemas/AgentConfig.json
+name: working_agent
+agent_class: core_custom_agent.my_agents.MyCustomAgent
+description: Handles all the work.
+my_field: my_field_value