A/B Testing Agent Variants – Agent Cloning with .clone()

Demonstrates .clone() for creating independent agent variants from a shared base configuration. The scenario: A/B testing two customer support agents – one using a formal tone and one using a casual tone – while sharing the same underlying tool (order lookup).

Tip

What you’ll learn How to attach tools to an agent using the fluent API.

Source: 10_cloning.py

adk-fluent

from adk_fluent import Agent


def lookup_order(order_id: str) -> str:
    """Look up the status of a customer order by its ID."""
    return f"Order {order_id}: shipped, arriving Thursday"


base = (
    Agent("support_base")
    .model("gemini-2.5-flash")
    .instruct("You are a customer support agent. Help customers with order inquiries.")
    .tool(lookup_order)
)

variant_a = base.clone("formal_support").instruct(
    "You are a customer support agent. Use formal, professional language. "
    "Address the customer as Sir or Madam. Be thorough and precise."
)
variant_b = base.clone("casual_support").instruct(
    "You are a customer support agent. Use friendly, casual language. "
    "Be warm and personable. Use the customer's first name."
)

Native ADK

# Native ADK has no clone mechanism. You must manually duplicate all parameters:
#   from google.adk.agents.llm_agent import LlmAgent
#
#   def lookup_order(order_id: str) -> str:
#       return f"Order {order_id}: shipped, arriving Thursday"
#
#   formal = LlmAgent(
#       name="formal",
#       model="gemini-2.5-flash",
#       instruction="Use formal, professional language when helping customers.",
#       tools=[lookup_order],
#   )
#   casual = LlmAgent(
#       name="casual",
#       model="gemini-2.5-flash",
#       instruction="Use friendly, casual language when helping customers.",
#       tools=[lookup_order],
#   )

Equivalence

# Clones are independent with their own names
assert variant_a._config["name"] == "formal_support"
assert variant_b._config["name"] == "casual_support"
# Each clone has its own instruction
assert "formal" in variant_a._config["instruction"]
assert "casual" in variant_b._config["instruction"]
# Original base is unchanged
assert base._config["name"] == "support_base"
assert "order inquiries" in base._config["instruction"]
# Both clones inherited the tool
assert len(variant_a._lists["tools"]) == 1
assert len(variant_b._lists["tools"]) == 1