feat: Add util to run ADK LLM Agent with simulation environment

PiperOrigin-RevId: 825674499
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Google Team Member
2025-10-29 13:05:33 -07:00
committed by Copybara-Service
parent e7f7705eba
commit 87f415a7c3
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# Example: optimizing an ADK agent with Genetic-Pareto
This directory contains an example demonstrating how to use the Agent Development
Kit (ADK) to run and optimize an LLM-based agent in a simulated environment with the Genetic-Pareto prompt optimization algorithm ([GEPA: Reflective Prompt Evolution Can Outperform Reinforcement Learning](https://arxiv.org/abs/2507.19457)) on benchmarks like Tau-bench.
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# Copyright 2025 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.
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# Copyright 2025 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.
"""ADK utils for a LLMAgent interacting with a simulation environment."""
from __future__ import annotations
import asyncio
from collections.abc import Generator
from typing import Any
from typing import Dict
from typing import Optional
from typing import Protocol
from typing import runtime_checkable
from absl import logging
from google.adk import runners
from google.adk.agents import base_agent
from google.adk.agents import llm_agent
from google.adk.agents import loop_agent
from google.adk.events import event as event_lib
from google.adk.tools import base_tool
from google.genai import types
class EnvResponse(Protocol):
"""Environment response protocol."""
observation: str
done: bool
reward: float
@runtime_checkable
class Env(Protocol):
"""Environment protocol."""
def step(self, action: types.Part) -> EnvResponse:
"""Steps the environment with the given action."""
...
def reset(self, task_index: int) -> EnvResponse:
"""Resets the environment to the given task index."""
...
class _Tool(base_tool.BaseTool):
"""A tool that executes an action in the environment."""
class Config:
arbitrary_types_allowed = True
def __init__(
self,
function_declaration: types.FunctionDeclaration,
env: Env,
):
"""Initializes the tool.
Args:
function_declaration: The function declaration of the tool.
env: The environment to interact with.
"""
super().__init__(
name=function_declaration.name,
description=function_declaration.description,
)
self._function_declaration = function_declaration
self._env = env
def _get_declaration(self) -> types.FunctionDeclaration:
return self._function_declaration
async def run_async(self, *, args: Dict[str, Any], tool_context: Any) -> str:
"""Runs the tool by converting tool call to env action and stepping env."""
env_response = self._env.step(
types.Part(function_call=types.FunctionCall(name=self.name, args=args))
)
# We modify the ADK session state with the updates from the environment,
# in particular `done` and `reward`. These can be consumed downstream for
# instance to extract the trajectory reward or interrupt the loop.
tool_context.actions.state_delta['done'] = env_response.done
tool_context.actions.state_delta['reward'] = env_response.reward
tool_context.actions.skip_summarization = True
if env_response.done:
tool_context.actions.escalate = True
return env_response.observation
def _adk_agent(
instruction: str,
tools: list[base_tool.BaseTool],
temperature: float,
model: str | None = None,
name: str | None = None,
) -> llm_agent.LlmAgent:
"""Creates an ADK LLM agent with the given instruction and tools.
Args:
instruction: The instruction for the agent.
tools: The tools for the agent to use.
temperature: The temperature for the LLM.
model: Model to use with the ADK LLMAgent ; defaults to `gemini-2.5-flash`.
name: Name to set for the ADK LLM agent.
Returns:
An ADK LLM agent.
"""
# TDOO - Allow more flexibility in configuring the agent used in the loop.
return llm_agent.LlmAgent(
name=name or 'agent',
model=model or 'gemini-2.5-flash',
instruction=instruction,
tools=tools,
generate_content_config=types.GenerateContentConfig(
temperature=temperature,
tool_config=types.ToolConfig(
function_calling_config=types.FunctionCallingConfig(
mode=types.FunctionCallingConfigMode.VALIDATED
)
),
),
)
class _UserAgent(base_agent.BaseAgent):
"""An agent that wraps the provided environment and simulates an user."""
env: Env
class Config:
arbitrary_types_allowed = True
async def _run_async_impl(self, ctx: Any) -> Any:
"""Runs the user agent."""
if not ctx.session.events:
raise ValueError(
'No prior session events, this is unexpected as the user agent cannot'
' be the first step in the interaction loop.'
)
last_event = ctx.session.events[-1]
# Function tool
if last_event.content and last_event.content.role == 'user':
return
if last_event.content and last_event.content.parts:
next_message = last_event.content.parts[-1].text
else:
logging.warn('Empty content with event=%s', last_event)
next_message = ''
env_response = self.env.step(types.Part(text=next_message))
output_event = event_lib.Event(
content=types.Content(
parts=[types.Part(text=env_response.observation)], role='user'
),
author='user',
)
if env_response.done:
output_event.actions.escalate = True
output_event.actions.state_delta['reward'] = env_response.reward
output_event.actions.state_delta['done'] = env_response.done
yield output_event
def run_environment_loop(
instruction: str,
env: Env,
temperature: float,
tools: list[types.FunctionDeclaration],
task_index: int,
max_num_steps: int = 30,
plugins: Optional[Any] = None,
agent_model: str | None = None,
agent_name: str | None = None,
) -> Generator[event_lib.Event]:
"""Defines and runs an ADK LLM Agent in the provided simulation environment.
Args:
instruction: The instruction for the agent.
env: The environment to interact with.
temperature: The temperature for the LLM.
tools: The tools for the agent to use.
task_index: The index of the task to run.
max_num_steps: The maximum number of steps to run LLM agent - environment
interaction loop.
plugins: Optional plugins to use in the runner.
agent_model: Model to use with the ADK LLMAgent ; defaults to
`gemini-2.5-flash`.
agent_name: Name to set for the ADK LLM agent.
Returns:
A generator of events from the agent run.
Yields:
All the events from the environment loop including:
- Initial message from environment reset
- LLMAgent generated text and function calls
- Environment tools / users generated text responses
- Environment user
"""
# We use an agent loop to orchestrate the llm-agent and the environment
# interactions. In particular to:
# - ensure that LLMAgent and environment / user are called one after the
# other
# - the number of interaction steps is pre-defined (early exit is possible).
agent = loop_agent.LoopAgent(
name='env_loop_agent',
max_iterations=max_num_steps,
sub_agents=[
_adk_agent(
instruction=instruction,
tools=[_Tool(t, env) for t in tools],
temperature=temperature,
model=agent_model,
name=agent_name,
),
_UserAgent(
name='user_agent',
env=env,
),
],
)
runner = runners.InMemoryRunner(
agent=agent,
app_name='eval_app',
plugins=plugins,
)
session = asyncio.run(
runner.session_service.create_session(
app_name='eval_app', user_id='eval_user'
)
)
env_reset_res = env.reset(task_index=task_index)
initial_message = types.Content(
role='user', parts=[types.Part(text=env_reset_res.observation)]
)
# The initial message is generated by the environment `reset` within the
# implementation of this function - as the first step of the trace.
# We yield this first step to ensure we provide a full trace to the user.
yield event_lib.Event(
author='user',
content=initial_message,
)
for event in runner.run(
user_id=session.user_id,
session_id=session.id,
new_message=initial_message,
):
yield event
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# Copyright 2025 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 asyncio
import dataclasses
from unittest import mock
from gepa import adk_agent
from google.adk import runners
from google.adk.agents import base_agent
from google.adk.events import event as event_lib
from google.adk.plugins import base_plugin
from google.genai import types
class _TestPlugin(base_plugin.BasePlugin):
def __init__(self, outputs):
super().__init__(name="test-pluggin")
self._model_output_idx = 0
self.got_llm_requests = []
self._outputs = outputs
async def before_model_callback(self, *, callback_context, llm_request):
self.got_llm_requests.append(llm_request)
if self._model_output_idx < len(self._outputs):
out = self._outputs[self._model_output_idx]
self._model_output_idx += 1
return out
return event_lib.Event(
error_code="empty test list",
author="agent",
)
@dataclasses.dataclass
class EnvResponse:
observation: str
done: bool
reward: float
class _TestEnv:
def __init__(self, responses):
self._responses = responses
self._idx = 0
def step(self, action):
del action
if self._idx < len(self._responses):
resp = self._responses[self._idx]
self._idx += 1
else:
resp = EnvResponse("out-of-bound", done=True, reward=0)
return resp
def reset(self, task_index: int):
del task_index
return EnvResponse("reset-obs", done=False, reward=42)
def test_default_flow():
model_outputs = [
event_lib.Event(
content=types.Content(
parts=[types.Part(text="ab")],
role="model",
),
author="agent",
),
event_lib.Event(
content=types.Content(
parts=[
types.Part(
function_call=types.FunctionCall(
name="test_tool",
args=dict(tool_inputs="fake-tool-inputs"),
)
)
],
role="model",
),
author="agent",
),
event_lib.Event(
content=types.Content(
parts=[types.Part(text="cd")],
role="model",
),
author="agent",
),
]
events = adk_agent.run_environment_loop(
instruction="some-instruction",
env=_TestEnv([
EnvResponse("some-obs-1", done=False, reward=123),
EnvResponse("tool-response", done=False, reward=45),
EnvResponse("some-obs-2", done=False, reward=67),
]),
temperature=0,
tools=[
types.FunctionDeclaration(
name="test_tool",
description="test_tool",
parameters={
"type": "object",
"properties": {
"tool_inputs": {
"type": "string",
"description": "tool_inputs",
}
},
},
)
],
task_index=0,
max_num_steps=3,
plugins=[
_TestPlugin(model_outputs),
],
)
events = list(events)
want = [
"reset-obs",
"ab",
"some-obs-1",
"test_tool",
"tool-response",
"cd",
"some-obs-2",
]
def _extract_from_event(event):
if not event.content:
return ""
if len(event.content.parts) != 1:
return ""
part = event.content.parts[0]
if part.function_call:
return part.function_call.name
if part.function_response:
return part.function_response.response.get("result")
return part.text
got = [_extract_from_event(e) for e in events]
assert got == want
got_rewards = [e.actions.state_delta.get("reward") for e in events]
assert got_rewards == [None, None, 123, None, 45, None, 67]
def test_intermediary_step_is_done():
model_outputs = [
event_lib.Event(
content=types.Content(
parts=[types.Part(text="ab")],
role="model",
),
author="agent",
),
event_lib.Event(
content=types.Content(
parts=[types.Part(text="cd")],
role="model",
),
author="agent",
),
]
events = adk_agent.run_environment_loop(
instruction="some-instruction",
env=_TestEnv([
EnvResponse("some-obs-1", done=True, reward=0),
EnvResponse("some-obs-2", done=False, reward=0),
]),
temperature=0,
tools=[],
task_index=0,
max_num_steps=5,
plugins=[
_TestPlugin(model_outputs),
],
)
want_text = ["reset-obs", "ab", "some-obs-1"]
got = [e.content.parts[0].text for e in events]
assert got == want_text
def test_intermediary_tool_step_is_done():
model_outputs = [
event_lib.Event(
content=types.Content(
parts=[types.Part(text="ab")],
role="model",
),
author="agent",
),
event_lib.Event(
content=types.Content(
parts=[
types.Part(
function_call=types.FunctionCall(
name="test_tool",
args=dict(tool_inputs="fake-tool-inputs"),
)
)
],
role="model",
),
author="agent",
),
event_lib.Event(
content=types.Content(
parts=[types.Part(text="cd")],
role="model",
),
author="agent",
),
]
events = adk_agent.run_environment_loop(
instruction="some-instruction",
env=_TestEnv([
EnvResponse("some-obs-1", done=False, reward=123),
EnvResponse("tool-response", done=True, reward=45),
EnvResponse("some-obs-2", done=False, reward=67),
]),
temperature=0,
tools=[
types.FunctionDeclaration(
name="test_tool",
description="test_tool",
parameters={
"type": "object",
"properties": {
"tool_inputs": {
"type": "string",
"description": "tool_inputs",
}
},
},
)
],
task_index=0,
max_num_steps=3,
plugins=[
_TestPlugin(model_outputs),
],
)
events = list(events)
want = ["reset-obs", "ab", "some-obs-1", "test_tool", "tool-response"]
def _extract_from_event(event):
if not event.content:
return ""
if len(event.content.parts) != 1:
return ""
part = event.content.parts[0]
if part.function_call:
return part.function_call.name
if part.function_response:
return part.function_response.response.get("result")
return part.text
got = [_extract_from_event(e) for e in events]
assert got == want
def test_llm_request():
model_outputs = [
event_lib.Event(
content=types.Content(
parts=[types.Part(text="ab")],
role="model",
),
author="agent",
),
event_lib.Event(
content=types.Content(
parts=[types.Part(text="cd")],
role="model",
),
author="agent",
),
]
test_plugin = _TestPlugin(model_outputs)
events = adk_agent.run_environment_loop(
instruction="some-instruction",
env=_TestEnv([
EnvResponse("some-obs-1", done=False, reward=123),
EnvResponse("some-obs-2", done=False, reward=67),
]),
temperature=0.123,
tools=[],
task_index=0,
max_num_steps=2,
plugins=[test_plugin],
)
_ = list(events)
assert len(test_plugin.got_llm_requests) == 2
got = test_plugin.got_llm_requests[-1]
assert "some-instruction" in got.config.system_instruction
assert got.config.temperature == 0.123
got_parts = [c.parts[0].text for c in got.contents]
assert got_parts == ["reset-obs", "ab", "some-obs-1"]
def test_model_name_is_set():
class _MockAgent(base_agent.BaseAgent):
async def _run_async_impl(self, ctx):
pass
async def _mock_create_session(*args, **kwargs):
del args, kwargs
await asyncio.sleep(0.1)
return
with mock.patch.object(runners, "InMemoryRunner") as mock_runner_cls:
mock_runner = mock_runner_cls.return_value
mock_runner.session_service.create_session.side_effect = (
_mock_create_session
)
mock_runner.run.return_value = []
next(
adk_agent.run_environment_loop(
instruction="some-instruction",
env=_TestEnv([]),
temperature=0.123,
tools=[],
task_index=0,
agent_model="some-test-model",
plugins=[_TestPlugin([])],
)
)
mock_runner_cls.assert_called_once()
_, runner_kwargs = mock_runner_cls.call_args
assert runner_kwargs["agent"].sub_agents[0].model == "some-test-model"