Google Apps Script 用 Slack API ライブラリ作った ref: https://qiita.com/yhay81/items/edf74af8efe3d3d1a1b5

file0.txt

var token = 'xoxb-34...みたいなトークン';
var slack = GASlacker.methods(token);

function doPost(e){
  var event = JSON.parse(e.postData.contents).event;
  if(event.text.match(/hello/)){
    var text = "Hello," + event.message.username;
    slack.chat.postMessage(event.channel, text);
  }
}

file1.txt

var token = 'xoxb-34...みたいなトークン';
var slack = GASlacker.methods(token);

function doPost(e){
  var event = JSON.parse(e.postData.contents).event;
  if(event.text.match(/hello/)){
    var text = "Hello," + event.message.username;
    slack.chat.postMessage(event.channel, text);
  }
}