Slack Reacjilator Demo

by slackAPI


Reacjilator for Slack

🇯🇵 README in Japanese is available: 日本語 README はこちら

Reacjilator translates a message when a user reacted with an emoji ("reacji"). For example, when a message gets a :flag-jp: reacji, this bot translate the original message to Japanese and post it under the message thread.

Reacjilator demo

Set Up Your Slack App

  1. Create an app at your Slack App Setting page at
  2. Enable the workspace events, reaction_added and point to
  3. Set the following scopes:
  • "chat:write:bot" (Send messages with chat.postMessage by a bot),
  • "reactions:read" (Access the workspace’s emoji reaction history)
  • "channels:read" (Access public channels info)
  • "*:history" (Access user's channels)
  1. Install the app and get a user token, begins with xoxp-


Rename the .env_test to .env and fill the env vars with your credentials. You also need Google credentials to use the Google translation API:


Get Your Slack credentials at Basic Information, auth token at OAuth & Permissions.

Get your Google Cloud project ID and API key at

Deployment Examples

Deploy on Google Cloud Functions

Please refer the google-cloud-functions branch.

Deploy on Heroku

Use this Heroku button to deploy to Heroku server. You just need to fill out the env vars with the info. No need to create an .env file.


When you deploy to Heroku, the request URL for the Event Subscription section on Slack App config page would be: