handoff-gpt5-to-gemini.py

from agents import Agent, ModelSettings, Runner, function_tool, handoff, set_default_openai_api
from agents.extensions.models.litellm_model import LitellmModel
from openai.types.shared import Reasoning

@function_tool
def echo_tool(input: str) -> str:
    return input

@function_tool
def speak_tool(input: str) -> str:
    return input

@function_tool
def final_tool(input: str) -> str:
    return input


gemini_model = LitellmModel(
    model="gemini/gemini-3-pro-preview"
)

agent1 = Agent(
    name="Gemini Agent",
    instructions="You are a helpful assistant",
    model=gemini_model,
    tools=[echo_tool, speak_tool, final_tool],
    model_settings=ModelSettings(reasoning=Reasoning(effort="low"))
)

agent2 = Agent(
    name="OpenAI Agent",
    instructions="You are a helpful assistant",
    model="gpt-5-mini",
    tools=[echo_tool, speak_tool, final_tool],
    model_settings=ModelSettings(reasoning=Reasoning(effort="low")),
    handoffs=[ handoff(agent1, nest_handoff_history=False) ]
)

result = Runner.run_sync(
    agent2, "handoff to Gemini Agent, then use echo_tool and speak_tool"
)
print("--------------------------------")
print(result.final_output)
print("----------")
print(result.to_input_list())