Bolt for JavaScript: Fastify Receiver

This module provides a Receiver implementation for Fastify users.

Getting Started

You can create a simple Node app project using the following package.json and tsconfig.json. Of course, if you would like to use some build tool such as webpack, you can go with your own way and add the necessary dependencies.

package.json

{
  "name": "bolt-fastify-app",
  "version": "0.1.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "rm -rf dist/ && tsc && npx ts-node src/index.ts"
  },
  "author": "Kazuhiro Sera",
  "license": "MIT",
  "dependencies": {
    "@slack/bolt": "^3.12.2",
    "fastify": "^3.27.4",
    "@seratch_/bolt-fastify": "^1.0.0"
  },
  "devDependencies": {
    "ts-node": "^10.5.0",
    "typescript": "^4.5.5"
  }
}

tsconfig.json

{
  "compilerOptions": {
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "allowJs": true,
    "esModuleInterop": true,
    "outDir": "dist",
  },
  "include": ["src/**/*"]
}

Create a new Slack app at api.slack.com/apps

The next step is to create a new Slack app configuration. You can use the following App Manifest configuration data for it.

display_information:
  name: fastify-oauth-test-app
features:
  bot_user:
    display_name: fastify-oauth-test-app
oauth_config:
  redirect_urls:
    - https://xxx.ngrok.io/slack/oauth_redirect
  scopes:
    bot:
      - commands
      - chat:write
      - app_mentions:read
settings:
  event_subscriptions:
    bot_events:
      - app_mention
  interactivity:
    is_enabled: true
  socket_mode_enabled: true

Place your source code in the project

The last step is to add your code in the project and spin up your app. You can use the following code as-is.

src/app.ts

import Fastify from 'fastify';
import { App, FileInstallationStore, LogLevel } from '@slack/bolt';
import { FileStateStore } from '@slack/oauth';
import { FastifyReceiver } from '@seratch_/bolt-fastify';

const fastify = Fastify({ logger: true });

fastify.get('/', async (_, res) => {
  res.redirect('/slack/install');
});

const receiver = new FastifyReceiver({
  signingSecret: process.env.SLACK_SIGNING_SECRET!,
  clientId: process.env.SLACK_CLIENT_ID,
  clientSecret: process.env.SLACK_CLIENT_SECRET,
  scopes: ['commands', 'chat:write', 'app_mentions:read'],
  installationStore: new FileInstallationStore(),
  installerOptions: {
    directInstall: true,
    stateStore: new FileStateStore({}),
  },
  fastify,
});

const app = new App({
  logLevel: LogLevel.DEBUG,
  receiver,
});

app.event('app_mention', async ({ event, say }) => {
  await say({
    text: `<@${event.user}> Hi there :wave:`,
    blocks: [
      {
        type: 'section',
        text: {
          type: 'mrkdwn',
          text: `<@${event.user}> Hi there :wave:`,
        },
      },
    ],
  });
});

app.command('/my-command', async ({ ack }) => {
  await ack('Hi there!');
});

app.shortcut('my-global-shortcut', async ({ ack, body, client }) => {
  await ack();
  await client.views.open({
    trigger_id: body.trigger_id,
    view: {
      type: 'modal',
      callback_id: 'my-modal',
      title: {
        type: 'plain_text',
        text: 'My App',
      },
      submit: {
        type: 'plain_text',
        text: 'Submit',
      },
      blocks: [
        {
          type: 'input',
          block_id: 'b',
          element: {
            type: 'plain_text_input',
            action_id: 'a',
          },
          label: {
            type: 'plain_text',
            text: 'Comment',
          },
        },
      ],
    },
  });
});

app.view('my-modal', async ({ view, ack, logger }) => {
  logger.info(view.state.values);
  await ack();
});

(async () => {
  await app.start();
  // eslint-disable-next-line no-console
  console.log('⚡️ Bolt app is running!');
})();

Finally, your app is now available for running! Set all the required env variables, hit npm start, and then enable your public URL endpoint (you may want to use some proxy tool such as ngrok).

export SLACK_CLIENT_ID=
export SLACK_CLIENT_SECRET=
export SLACK_SIGNING_SECRET=
export SLACK_STATE_SECRET=secret
export SLACK_APP_TOKEN=
npm start
# Visit https://{your public domain}/slack/install

Now you can install the app into your Slack workspace from https://{your public domain}/slack/install. Enjoy!