import asyncio import random from typing import Any from pydantic import BaseModel from agents import Agent, RunContextWrapper, RunHooks, Runner, Tool, Usage, function_tool class ExampleHooks(RunHooks): def __init__(self): self.event_counter = 0 def _usage_to_str(self, usage: Usage) -> str: return f"{usage.requests} requests, {usage.input_tokens} input tokens, {usage.output_tokens} output tokens, {usage.total_tokens} total tokens" async def on_agent_start(self, context: RunContextWrapper, agent: Agent) -> None: self.event_counter += 1 print( f"### {self.event_counter}: Agent {agent.name} started. Usage: {self._usage_to_str(context.usage)}" ) async def on_agent_end(self, context: RunContextWrapper, agent: Agent, output: Any) -> None: self.event_counter += 1 print( f"### {self.event_counter}: Agent {agent.name} ended with output {output}. Usage: {self._usage_to_str(context.usage)}" ) async def on_tool_start(self, context: RunContextWrapper, agent: Agent, tool: Tool) -> None: self.event_counter += 1 print( f"### {self.event_counter}: Tool {tool.name} started. Usage: {self._usage_to_str(context.usage)}" ) async def on_tool_end( self, context: RunContextWrapper, agent: Agent, tool: Tool, result: str ) -> None: self.event_counter += 1 print( f"### {self.event_counter}: Tool {tool.name} ended with result {result}. Usage: {self._usage_to_str(context.usage)}" ) async def on_handoff( self, context: RunContextWrapper, from_agent: Agent, to_agent: Agent ) -> None: self.event_counter += 1 print( f"### {self.event_counter}: Handoff from {from_agent.name} to {to_agent.name}. Usage: {self._usage_to_str(context.usage)}" ) hooks = ExampleHooks() ### @function_tool def random_number(max: int) -> int: """Generate a random number up to the provided max.""" return random.randint(0, max) @function_tool def multiply_by_two(x: int) -> int: """Return x times two.""" return x * 2 class FinalResult(BaseModel): number: int multiply_agent = Agent( name="Multiply Agent", instructions="Multiply the number by 2 and then return the final result.", tools=[multiply_by_two], output_type=FinalResult, ) start_agent = Agent( name="Start Agent", instructions="Generate a random number. If it's even, stop. If it's odd, hand off to the multipler agent.", tools=[random_number], output_type=FinalResult, handoffs=[multiply_agent], ) async def main() -> None: user_input = input("Enter a max number: ") await Runner.run( start_agent, hooks=hooks, input=f"Generate a random number between 0 and {user_input}.", ) print("Done!") if __name__ == "__main__": asyncio.run(main()) """ $ python examples/basic/lifecycle_example.py Enter a max number: 250 ### 1: Agent Start Agent started. Usage: 0 requests, 0 input tokens, 0 output tokens, 0 total tokens ### 2: Tool random_number started. Usage: 1 requests, 148 input tokens, 15 output tokens, 163 total tokens ### 3: Tool random_number ended with result 101. Usage: 1 requests, 148 input tokens, 15 output tokens, 163 total tokens ### 4: Agent Start Agent started. Usage: 1 requests, 148 input tokens, 15 output tokens, 163 total tokens ### 5: Handoff from Start Agent to Multiply Agent. Usage: 2 requests, 323 input tokens, 30 output tokens, 353 total tokens ### 6: Agent Multiply Agent started. Usage: 2 requests, 323 input tokens, 30 output tokens, 353 total tokens ### 7: Tool multiply_by_two started. Usage: 3 requests, 504 input tokens, 46 output tokens, 550 total tokens ### 8: Tool multiply_by_two ended with result 202. Usage: 3 requests, 504 input tokens, 46 output tokens, 550 total tokens ### 9: Agent Multiply Agent started. Usage: 3 requests, 504 input tokens, 46 output tokens, 550 total tokens ### 10: Agent Multiply Agent ended with output number=202. Usage: 4 requests, 714 input tokens, 63 output tokens, 777 total tokens Done! """