Claude API 多轮对话怎么写？正确传递消息历史

把方法变成一次练习

import {pathToFileURL} from 'node:url';

export function createConversation({apiKey,model,workspace,fetchImpl=fetch,timeoutMs=20000}) {
  if(!apiKey || !model)throw new Error('请先提供API Key与账户可用的模型ID');
  let history=[],busy=false;
  return {
    async send(text) {
      if(typeof text!=='string'||!text.trim())throw new Error('消息不能为空');
      if(busy)throw new Error('当前会话正在请求，请等待上一轮完成');
      busy=true;
      try {
        const candidate=[...structuredClone(history),{role:'user',content:text}];
        const response=await fetchImpl('https://api.anthropic.com/v1/messages',{
          method:'POST',redirect:'error',signal:AbortSignal.timeout(timeoutMs),
          headers:{'x-api-key':apiKey,'anthropic-version':'2023-06-01',
            'content-type':'application/json',
            ...(workspace?{'anthropic-workspace-id':workspace}:{})},
          body:JSON.stringify({model,max_tokens:1024,messages:candidate})
        });
        const requestId=response.headers.get('request-id');
        if(!response.ok) {
          await response.body?.cancel();
          throw new Error('HTTP '+response.status+'；request-id='+(requestId||'未提供'));
        }
        const data=await response.json();
        if(data.role!=='assistant'||!Array.isArray(data.content)||!data.content.length)throw new Error('消息结构不符合预期，未提交本轮历史');
        if(data.content.some(block=>block.type==='tool_use'))throw new Error('本示例未实现工具循环，未提交本轮历史');
        if(data.stop_reason!=='end_turn'){
          const error=new Error('回复未自然结束；stop_reason='+(data.stop_reason??'未提供')+'，本轮未提交历史；请核对截断或其他分支');
          error.stopReason=data.stop_reason??null;throw error;
        }
        history=[...candidate,{role:'assistant',content:structuredClone(data.content)}];
        return {text:data.content.filter(block=>block.type==='text').map(block=>block.text).join('\n'),requestId,stopReason:data.stop_reason,usage:data.usage};
      } finally {busy=false;}
    },
    get completedTurns(){return history.length/2;}
  };
}

if(process.argv[1]&&import.meta.url===pathToFileURL(process.argv[1]).href) {
  try {
    const chat=createConversation({apiKey:process.env.ANTHROPIC_API_KEY,
      model:process.env.CLAUDE_MODEL,workspace:process.env.ANTHROPIC_WORKSPACE_ID});
    for(const question of ['把“用户提交后没反应”改写成一个需要补充信息的问题。','保留上一个问题，再补充运行环境。']) {
      const reply=await chat.send(question);
      console.log(reply.text||'没有可见文本，请检查模型与输出预算。');
      console.error(JSON.stringify({requestId:reply.requestId,stopReason:reply.stopReason,usage:reply.usage}));
    }
  } catch(error) {console.error(error.message);process.exitCode=1;}
}