ADK Single-turn Agent as Sub-agent Sample
Overview
This sample demonstrates how a "single_turn" mode agent can act as an autonomous sub-agent to an LLM agent, utilizing schemas and tools without ever interacting with the user.
Note: This is the recommended mechanism to replace the older AgentTool pattern. Unlike AgentTool, using a single_turn sub-agent preserves the sub-agent's internal interactions (like tool calls) in the session history.
Single-turn agents are designed to execute their function fully in one prompt-response cycle. In this sample:
phone_recommender: A single-turn agent that receives structured input (UserPreferences), uses a mocked tool (check_phone_price), and returns structured output (PhoneRecommendation).
root_agent: The main agent that interacts with the user, translates their natural language request into the structured UserPreferences, and delegates to phone_recommender.
-
I need a phone mostly for gaming. I have about $1000 to spend.
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What is a good cheap phone from Google for basic tasks?
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I love photography but prefer smaller phones. My budget is $600.
Graph
graph TD
root_agent --> phone_recommender
phone_recommender -.->|uses| check_phone_price[check_phone_price tool]
How To
-
Define a sub-agent with Mode: llmagent.ModeSingleTurn, InputSchema, OutputSchema:
phoneRecommender, err := llmagent.New(llmagent.Config{
Name: "phone_recommender",
Model: model,
Mode: llmagent.ModeSingleTurn,
InputSchema: userPreferencesSchema,
OutputSchema: phoneRecommendationSchema,
Tools: []tool.Tool{checkPhonePriceTool},
// ...
})
-
Assign it to a parent agent:
rootAgent, err := llmagent.New(llmagent.Config{
SubAgents: []agent.Agent{phoneRecommender},
// ...
})
Run
Set your API key and run the sample with the console launcher:
export GOOGLE_API_KEY=...
go run ./examples/multiagent/single_turn console