coabot/src/url_metadata.js

const bot = require('bbot');
const request = require('request');

bot.global.text(/(https?:\/\/.*)[, $]?/i, (b) => {
  request(b.match[1], (err, res, body) => {
    if (!err) {
      var re = /<title>([^<]*)<\/title>/gi;
      var match = re.exec(body);
      if (match && match[1]) {
        b.respond("[:link:](" + b.match[1] + ") _" + match[1] + "_");
      }
    }
  });
}, {
  id: 'get-url-metadata'
});