AI Debate with Turn Taking

The following code snippets demonstrate how to implement a multi-agent conversation system with turn-taking using Mastra. This example creates a debate between two AI agents (an optimist and a skeptic) who discuss a user-provided topic, taking turns to respond to each other’s points.

Creating Agents with Voice Capabilities

First, we need to create two agents with distinct personalities and voice capabilities:

src/mastra/agents/index.ts


import { openai } from '@ai-sdk/openai';
import { Agent } from '@mastra/core/agent';
import { OpenAIVoice } from '@mastra/voice-openai';
 
export const optimistAgent = new Agent({
    name: "Optimist",
    instructions: "You are an optimistic debater who sees the positive side of every topic. Keep your responses concise and engaging, about 2-3 sentences.",
    model: openai("gpt-4o"),
    voice: new OpenAIVoice({
        speaker: "alloy"
    }),
});
 
export const skepticAgent = new Agent({
    name: "Skeptic",
    instructions: "You are a RUDE skeptical debater who questions assumptions and points out potential issues. Keep your responses concise and engaging, about 2-3 sentences.",
    model: openai("gpt-4o"),
    voice: new OpenAIVoice({
        speaker: "echo"
    }),
});

Registering the Agents with Mastra

Next, register both agents with your Mastra instance:

src/mastra/index.ts


import { createLogger } from '@mastra/core/logger';
import { Mastra } from '@mastra/core/mastra';
import { optimistAgent, skepticAgent } from './agents';
 
export const mastra = new Mastra({
  agents: { 
    optimistAgent,
    skepticAgent 
  },
  logger: createLogger({
    name: 'Mastra',
    level: 'info',
  }),
});

Managing Turn-Taking in the Debate

This example demonstrates how to manage the turn-taking flow between agents, ensuring each agent responds to the previous agent’s statements:

src/debate/turn-taking.ts


import { mastra } from "../../mastra";
import { playAudio, Recorder } from "@mastra/node-audio";
import * as p from "@clack/prompts";
 
// Helper function to format text with line wrapping
function formatText(text: string, maxWidth: number): string {
  const words = text.split(" ");
  let result = "";
  let currentLine = "";
 
  for (const word of words) {
    if (currentLine.length + word.length + 1 <= maxWidth) {
      currentLine += (currentLine ? " " : "") + word;
    } else {
      result += (result ? "\n" : "") + currentLine;
      currentLine = word;
    }
  }
 
  if (currentLine) {
    result += (result ? "\n" : "") + currentLine;
  }
 
  return result;
}
 
// Initialize audio recorder
const recorder = new Recorder({
  outputPath: "./debate.mp3",
});
 
// Process one turn of the conversation
async function processTurn(
  agentName: "optimistAgent" | "skepticAgent",
  otherAgentName: string,
  topic: string,
  previousResponse: string = ""
) {
  const agent = mastra.getAgent(agentName);
  const spinner = p.spinner();
  spinner.start(`${agent.name} is thinking...`);
 
  let prompt;
  if (!previousResponse) {
    // First turn
    prompt = `Discuss this topic: ${topic}. Introduce your perspective on it.`;
  } else {
    // Responding to the other agent
    prompt = `The topic is: ${topic}. ${otherAgentName} just said: "${previousResponse}". Respond to their points.`;
  }
 
  // Generate text response
  const { text } = await agent.generate(prompt, {
    temperature: 0.9,
  });
 
  spinner.message(`${agent.name} is speaking...`);
 
  // Convert to speech and play
  const audioStream = await agent.voice.speak(text, {
    speed: 1.2,
    responseFormat: "wav", // Optional: specify a response format
  });
 
  if (audioStream) {
    audioStream.on("data", (chunk) => {
      recorder.write(chunk);
    });
  }
 
  spinner.stop(`${agent.name} said:`);
 
  // Format the text to wrap at 80 characters for better display
  const formattedText = formatText(text, 80);
  p.note(formattedText, agent.name);
 
  if (audioStream) {
    const speaker = playAudio(audioStream);
 
    await new Promise<void>((resolve) => {
      speaker.once("close", () => {
        resolve();
      });
    });
  }
 
  return text;
}
 
// Main function to run the debate
export async function runDebate(topic: string, turns: number = 3) {
  recorder.start();
 
  p.intro("AI Debate - Two Agents Discussing a Topic");
  p.log.info(`Starting a debate on: ${topic}`);
  p.log.info(
    `The debate will continue for ${turns} turns each. Press Ctrl+C to exit at any time.`
  );
 
  let optimistResponse = "";
  let skepticResponse = "";
  const responses = [];
 
  for (let turn = 1; turn <= turns; turn++) {
    p.log.step(`Turn ${turn}`);
 
    // Optimist's turn
    optimistResponse = await processTurn(
      "optimistAgent",
      "Skeptic",
      topic,
      skepticResponse
    );
 
    responses.push({
      agent: "Optimist",
      text: optimistResponse,
    });
 
    // Skeptic's turn
    skepticResponse = await processTurn(
      "skepticAgent",
      "Optimist",
      topic,
      optimistResponse
    );
 
    responses.push({
      agent: "Skeptic",
      text: skepticResponse,
    });
  }
 
  recorder.end();
  p.outro("Debate concluded! The full audio has been saved to debate.mp3");
 
  return responses;
}

Running the Debate from the Command Line

Here’s a simple script to run the debate from the command line:

src/index.ts


import { runDebate } from './debate/turn-taking';
import * as p from '@clack/prompts';
 
async function main() {
    // Get the topic from the user
    const topic = await p.text({
        message: 'Enter a topic for the agents to discuss:',
        placeholder: 'Climate change',
        validate(value) {
            if (!value) return 'Please enter a topic';
            return;
        },
    });
 
    // Exit if cancelled
    if (p.isCancel(topic)) {
        p.cancel('Operation cancelled.');
        process.exit(0);
    }
 
    // Get the number of turns
    const turnsInput = await p.text({
        message: 'How many turns should each agent have?',
        placeholder: '3',
        initialValue: '3',
        validate(value) {
            const num = parseInt(value);
            if (isNaN(num) || num < 1) return 'Please enter a positive number';
            return;
        },
    });
 
    // Exit if cancelled
    if (p.isCancel(turnsInput)) {
        p.cancel('Operation cancelled.');
        process.exit(0);
    }
 
    const turns = parseInt(turnsInput as string);
 
    // Run the debate
    await runDebate(topic as string, turns);
}
 
main().catch((error) => {
    p.log.error('An error occurred:');
    console.error(error);
    process.exit(1);
});

Creating a Web Interface for the Debate

For web applications, you can create a simple Next.js component that allows users to start a debate and listen to the agents’ responses:

app/components/DebateInterface.tsx


'use client';
 
import { useState, useRef } from 'react';
import { MastraClient } from '@mastra/client-js';
 
const mastraClient = new MastraClient({
  baseUrl: process.env.NEXT_PUBLIC_MASTRA_URL || 'http://localhost:4111',
});
 
export default function DebateInterface() {
  const [topic, setTopic] = useState('');
  const [turns, setTurns] = useState(3);
  const [isDebating, setIsDebating] = useState(false);
  const [responses, setResponses] = useState<any[]>([]);
  const [isPlaying, setIsPlaying] = useState(false);
  const audioRef = useRef<HTMLAudioElement>(null);
 
  // Function to start the debate
  const startDebate = async () => {
    if (!topic) return;
    
    setIsDebating(true);
    setResponses([]);
    
    try {
      const optimist = mastraClient.getAgent('optimistAgent');
      const skeptic = mastraClient.getAgent('skepticAgent');
      
      const newResponses = [];
      let optimistResponse = "";
      let skepticResponse = "";
      
      for (let turn = 1; turn <= turns; turn++) {
        // Optimist's turn
        let prompt;
        if (turn === 1) {
          prompt = `Discuss this topic: ${topic}. Introduce your perspective on it.`;
        } else {
          prompt = `The topic is: ${topic}. Skeptic just said: "${skepticResponse}". Respond to their points.`;
        }
        
        const optimistResult = await optimist.generate({
          messages: [{ role: 'user', content: prompt }],
        });
        
        optimistResponse = optimistResult.text;
        newResponses.push({
          agent: 'Optimist',
          text: optimistResponse
        });
        
        // Update UI after each response
        setResponses([...newResponses]);
        
        // Skeptic's turn
        prompt = `The topic is: ${topic}. Optimist just said: "${optimistResponse}". Respond to their points.`;
        
        const skepticResult = await skeptic.generate({
          messages: [{ role: 'user', content: prompt }],
        });
        
        skepticResponse = skepticResult.text;
        newResponses.push({
          agent: 'Skeptic',
          text: skepticResponse
        });
        
        // Update UI after each response
        setResponses([...newResponses]);
      }
    } catch (error) {
      console.error('Error starting debate:', error);
    } finally {
      setIsDebating(false);
    }
  };
 
  // Function to play audio for a specific response
  const playAudio = async (text: string, agent: string) => {
    if (isPlaying) return;
    
    try {
      setIsPlaying(true);
      const agentClient = mastraClient.getAgent(agent === 'Optimist' ? 'optimistAgent' : 'skepticAgent');
      
      const audioResponse = await agentClient.voice.speak(text);
      
      if (!audioResponse.body) {
        throw new Error('No audio stream received');
      }
      
      // Convert stream to blob
      const reader = audioResponse.body.getReader();
      const chunks = [];
      
      while (true) {
        const { done, value } = await reader.read();
        if (done) break;
        chunks.push(value);
      }
      
      const blob = new Blob(chunks, { type: 'audio/mpeg' });
      const url = URL.createObjectURL(blob);
      
      if (audioRef.current) {
        audioRef.current.src = url;
        audioRef.current.onended = () => {
          setIsPlaying(false);
          URL.revokeObjectURL(url);
        };
        audioRef.current.play();
      }
    } catch (error) {
      console.error('Error playing audio:', error);
      setIsPlaying(false);
    }
  };
 
  return (
    <div className="max-w-4xl mx-auto p-4">
      <h1 className="text-2xl font-bold mb-4">AI Debate with Turn Taking</h1>
      
      <div className="mb-6">
        <label className="block mb-2">Debate Topic:</label>
        <input
          type="text"
          value={topic}
          onChange={(e) => setTopic(e.target.value)}
          className="w-full p-2 border rounded"
          placeholder="e.g., Climate change, AI ethics, Space exploration"
        />
      </div>
      
      <div className="mb-6">
        <label className="block mb-2">Number of Turns (per agent):</label>
        <input
          type="number"
          value={turns}
          onChange={(e) => setTurns(parseInt(e.target.value))}
          min={1}
          max={10}
          className="w-full p-2 border rounded"
        />
      </div>
      
      <button
        onClick={startDebate}
        disabled={isDebating || !topic}
        className="px-4 py-2 bg-blue-500 text-white rounded disabled:bg-gray-300"
      >
        {isDebating ? 'Debate in Progress...' : 'Start Debate'}
      </button>
      
      <audio ref={audioRef} className="hidden" />
      
      {responses.length > 0 && (
        <div className="mt-8">
          <h2 className="text-xl font-semibold mb-4">Debate Transcript</h2>
          
          <div className="space-y-4">
            {responses.map((response, index) => (
              <div 
                key={index}
                className={`p-4 rounded ${
                  response.agent === 'Optimist' ? 'bg-blue-100' : 'bg-gray-100'
                }`}
              >
                <div className="flex justify-between items-center">
                  <div className="font-bold">{response.agent}:</div>
                  <button
                    onClick={() => playAudio(response.text, response.agent)}
                    disabled={isPlaying}
                    className="text-sm px-2 py-1 bg-blue-500 text-white rounded disabled:bg-gray-300"
                  >
                    {isPlaying ? 'Playing...' : 'Play'}
                  </button>
                </div>
                <p className="mt-2">{response.text}</p>
              </div>
            ))}
          </div>
        </div>
      )}
    </div>
  );
}

This example demonstrates how to create a multi-agent conversation system with turn-taking using Mastra. The agents engage in a debate on a user-chosen topic, with each agent responding to the previous agent’s statements. The system also converts each agent’s responses to speech, providing an immersive debate experience.

You can view the complete implementation of the AI Debate with Turn Taking on our GitHub repository.

View Example on GitHub