George Weale
a308848969
Co-authored-by: George Weale <gweale@google.com> PiperOrigin-RevId: 962282749
113 lines
3.6 KiB
Python
113 lines
3.6 KiB
Python
# Copyright 2026 Google LLC
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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from __future__ import annotations
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from typing import Generator
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from google.adk import Agent
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from google.adk import Event
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from google.adk import Workflow
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from google.adk.apps import ResumabilityConfig
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from google.adk.apps.app import App
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from google.adk.workflow import node
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from pydantic import BaseModel
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from pydantic import Field
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# 1. Define schemas
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class CustomerLookupArgs(BaseModel):
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user_id: str = Field(description="The customer's unique identifier.")
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from google.adk import Context
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from google.adk.events import RequestInput
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# 2. Define a regular Node using the @node decorator.
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# This Node is wrapped as a NodeTool automatically by the Agent.
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# As a NodeTool, it has the ability to yield intermediate Events during execution.
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# Annotate the yield type with the data the tool returns, not the Event and
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# RequestInput control-flow items, so the tool's response schema stays small.
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@node(rerun_on_resume=True)
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def calculate_discount(tier: str, ctx: Context) -> Generator[str, None, None]:
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"""Calculates the discount percentage based on customer tier.
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Args:
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tier: The customer's membership tier (e.g., VIP, Standard).
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"""
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yield Event(message=f"Checking discount rules for tier '{tier}'...")
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resume_input = ctx.resume_inputs.get("confirm_vip_discount")
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if "VIP" in tier:
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if not resume_input:
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yield RequestInput(
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interrupt_id="confirm_vip_discount",
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message=f"Apply VIP discount for tier '{tier}'?",
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)
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return
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user_response = (
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resume_input.get("text")
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if isinstance(resume_input, dict)
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else resume_input
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)
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if str(user_response).lower() in ("yes", "y", "true"):
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discount = "20% off"
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else:
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discount = "5% off (VIP declined)"
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else:
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discount = "5% off"
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yield discount
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# 3. Define a Workflow.
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# This Workflow is wrapped as a NodeTool automatically by the Agent.
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def lookup_customer_data(node_input: CustomerLookupArgs, ctx) -> dict[str, str]:
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return {"user_id": node_input.user_id, "tier": "Verified VIP Member"}
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customer_lookup_workflow = Workflow(
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name="customer_lookup_workflow",
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description="Looks up customer status and tier by user_id.",
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input_schema=CustomerLookupArgs,
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edges=[
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("START", lookup_customer_data),
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],
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)
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# 4. Define the Agent that uses both Node and Workflow as tools.
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root_agent = Agent(
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name="customer_service_agent",
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instruction="""
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You are a customer service assistant.
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1. First, call `customer_lookup_workflow` using the user_id to get their membership tier.
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2. Then, call `calculate_discount` node with that tier to find out what discount they get.
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Summarize these details for the customer.
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""",
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tools=[customer_lookup_workflow, calculate_discount],
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)
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# Wrap the agent in an App and enable resumability. This is required because
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# the `calculate_discount` tool yields a RequestInput event which pauses
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# execution, and we need to resume the agent in a subsequent turn.
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app = App(
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name="node_as_tool",
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root_agent=root_agent,
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resumability_config=ResumabilityConfig(is_resumable=True),
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)
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