Hooks

from opperai.agent import Agent, Hooks, tool

hooks = Hooks(
    on_agent_start=lambda ctx: print(f'-> {ctx["agent"]}: {ctx["input"]}'),
    on_tool_start=lambda ctx: print(f'  tool {ctx["name"]}({ctx["input"]})'),
    on_tool_end=lambda ctx: print(f'  -> {ctx["output"]} ({ctx["duration_ms"]:.0f}ms)'),
    on_agent_end=lambda ctx: print(
        f'<- done in {ctx["result"].meta.iterations} iterations'
        if ctx.get("result") else f'<- failed: {ctx.get("error")}'
    ),
)

agent = Agent(name="city-expert", instructions="...", tools=[lookup_city], hooks=hooks)

import { Agent, type Hooks } from "opperai";

const hooks: Hooks = {
  onAgentStart: ({ agent, input }) => console.log(`-> ${agent}: ${input}`),
  onToolStart: ({ name, input }) => console.log(`  tool ${name}(${JSON.stringify(input)})`),
  onToolEnd: ({ name, output, durationMs }) =>
    console.log(`  -> ${JSON.stringify(output)} (${durationMs}ms)`),
  onAgentEnd: ({ result, error }) =>
    error
      ? console.log(`<- failed: ${error.message}`)
      : console.log(`<- done in ${result!.meta.iterations} iterations`),
};

const agent = new Agent({ name: "city-expert", instructions: "...", tools: [lookupCity], hooks });