Deferring app initialization

Bolt offers a way to defer full initialization via the deferInitialization option and to call the equivalent App#init() in your code, putting more control over asynchronous execution required for initialization into your hands as the developer.

info

If you call start() before init(), Bolt will raise an exception.

Example

const { App } = require('@slack/bolt');

// deferInitialization is one of the options you can set in the constructor
const app = new App({
  token,
  signingSecret,
  deferInitialization: true,
});

(async () => {
  try {
    // Must call init() before start() within an async function
    await app.init();
    // Now safe to call start()
    await app.start(process.env.PORT || 3000);
  } catch (e) {
    app.logger.error(e);
    process.exit(1);
  }
})()