Bolt for JavaScript

Since v3.7.0, you can add custom HTTP routes by passing a customRoutes array to the App constructor. Each object in the array must include:

• path: The URL path for the route.
• method: A string or an array of strings representing the HTTP methods (e.g., 'GET', ['POST', 'PUT']).
• handler: A function to handle the request, receiving req and res objects.

Starting from v3.13.0, the default HTTPReceiver and SocketModeReceiver support dynamic route parameters (e.g., /music/:genre), allowing you to access URL values via req.params.

You can specify the port for these routes using installerOptions.port in the App constructor. The default port is 3000.

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

// Initialize the Bolt app with custom routes
const app = new App({
  token: process.env.SLACK_BOT_TOKEN,
  signingSecret: process.env.SLACK_SIGNING_SECRET,
  customRoutes: [
    {
      path: '/health-check',
      method: ['GET'],
      handler: (req, res) => {
        res.writeHead(200);
        res.end(`Things are going just fine at ${req.headers.host}!`);
      },
    },
    {
      path: '/music/:genre',
      method: ['GET'],
      handler: (req, res) => {
        res.writeHead(200);
        res.end(`Oh? ${req.params.genre}? That slaps!`);
      },
    },
  ],
  installerOptions: {
    port: 3001,
  },
});

(async () => {
  await app.start();
  app.logger.info('⚡️ Bolt app started');
})();

To distribute a Slack app, you must implement the OAuth flow. Bolt handles routing, state parameter validation, and passing installation information to your app.

To enable OAuth, you must provide:

• clientId, clientSecret, stateSecret, scopes (Required)
• installationStore (Highly recommended for production to save and retrieve installation information)

For development and testing, you can use FileInstallationStore from @slack/oauth, but it is not recommended for production. In production, you should implement a custom installationStore using a real database.

const { App } = require('@slack/bolt');
const { FileInstallationStore } = require('@slack/oauth');
const app = new App({
  signingSecret: process.env.SLACK_SIGNING_SECRET,
  clientId: process.env.SLACK_CLIENT_ID,
  clientSecret: process.env.SLACK_CLIENT_SECRET,
  stateSecret: process.env.SLACK_STATE_SECRET,
  scopes: ['channels:history', 'chat:write', 'commands'],
  installationStore: new FileInstallationStore(),
});

If you are using the built-in ExpressReceiver, you can add custom routes or middleware by accessing the router property. The receiver.router exposes the internal Express Router instance used by the App, allowing you to use standard Express methods like .use(), .get(), .post(), etc., to handle web requests outside of Slack's event system.

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

// Explicitly create the Bolt Receiver
const receiver = new ExpressReceiver({ signingSecret: process.env.SLACK_SIGNING_SECRET });

// Create the App using this receiver
const app = new App({
  token: process.env.SLACK_BOT_TOKEN,
  receiver
});

// Define Slack-specific logic using App methods
app.event('message', async ({ event, client }) => {
  // Do some slack-specific stuff here
  await client.chat.postMessage(...);
});

// Use receiver.router to add middleware
receiver.router.use((req, res, next) => {
  app.logger.info(`Request time: ${Date.now()}`);
  next();
});

// Use receiver.router to define other web request handlers
receiver.router.post('/secret-page', (req, res) => {
  // Handle standard Express request and response
  res.send('yay!');
});

(async () => {
  await app.start();
  app.logger.info('⚡️ Bolt app started');
})();