How to Set Up Automated Notifications for CI Builds with Slack and Twilio

December 11, 2023
Written by
Udensi Fortune
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Automated notifications are very important in your CI/CD pipelines to ensure that you remain well-informed, react promptly to build statuses, and swiftly address any issues that arise.

In this tutorial, I will show you how to implement a system for delivering updates to a Slack channel and through Twilio Programmable SMS using Slack and Twilio orbs available in the CircleCI orb registry. While implementing this feature from the ground up could be a complex task, the use of orbs establishes this notification system with minimal code, streamlining the process to just a few lines.


To complete this tutorial, you will need the following:

Set Up the Nest.js Application

First, create a Nest.js application that outputs a brief message. After that, you'll write a test to make sure the program sends back the appropriate message. The build on CircleCI will begin when you publish your code to GitHub. As soon as the build is complete, a customized message will be delivered via SMS to both the chosen phone number and the designated Slack workspace.

To begin, run this command:

nest new nest-slack-notifications

You will get this output:

⚡  We will scaffold your app in a few seconds.

? Which package manager would you ❤️  to use? (Use arrow keys)
> npm

Choose the npm option. After that, you will get the following output:

CREATE nest-slack-notifications/.prettierrc (51 bytes)
CREATE nest-slack-notifications/nest-cli.json (171 bytes)
CREATE nest-slack-notifications/package.json (1965 bytes)
CREATE nest-slack-notifications/ (3340 bytes)
CREATE nest-slack-notifications/ (97 bytes)
CREATE nest-slack-notifications/tsconfig.json (546 bytes)
CREATE nest-slack-notifications/src/app.controller.ts (274 bytes)        
CREATE nest-slack-notifications/src/app.module.ts (249 bytes)
CREATE nest-slack-notifications/src/app.service.ts (142 bytes)
CREATE nest-slack-notifications/src/main.ts (208 bytes)
CREATE nest-slack-notifications/src/app.controller.spec.ts (617 bytes)
CREATE nest-slack-notifications/test/jest-e2e.json (183 bytes)
CREATE nest-slack-notifications/test/app.e2e-spec.ts (630 bytes)

▹▹▹▹▸ Installation in progress... ☕

When the installation is successful, you will see the following results:

🚀  Successfully created project nest-slack-notifications
👉  Get started with the following commands:

$ cd nest-slack-notifications
$ npm run start

                          Thanks for installing Nest 🙏
                 Please consider donating to our open collective
                        to help us maintain this package.

               🍷  Donate:

The application will be created in a new directory named nest-slack-notifications. Change to the directory and start the application to check that everything's working by running the commands below:

cd nest-slack-notifications
npm run start:dev

The application will be available on http://localhost:3000. If the application is running, you will see a page similar to the screenshot below:

Screenshot of "Hello World" on http://localhost:3000

This process outputs a Hello World! message which indicates that your application is running successfully.

To also run the test locally in your terminal, the Nest.js application has an integrated testing framework known as Jest. Jest provides assert functions by default. Additionally, a test script file at src/app.controller.spec.ts has been included to verify that the application responded Hello World!

Now, exit the existing process by entering CTRL + C and use the following command to run the test locally to ensure that the application is running successfully:

npm run test

If your application is running successfully, you will get a similar result to this:

> nest-slack-notifications@0.0.1 test
> jest

 PASS  src/app.controller.spec.ts (6.725 s)
      √ should return "Hello World!" (35 ms)                             
Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        7.045 s
Ran all test suites.

Add the CircleCI Configuration

To set up CircleCI for continuous integration, you need to add a configuration file. To do this, create a folder called .circleci at the application root and create a new file called config.yml inside the folder. Copy and paste the following code into the newly created file .circleci/config.yml:

version: 2.1
  node: circleci/node@5.0.3
      name: node/default
      - checkout
      - run: sudo npm install -g npm@latest
      - run:
          name: Install dependencies
          command: npm install
      - run: npm test
      - build-test-and-notify

In the config file above, you have installed all of the project's dependencies and specified the Node.js orb version to be used from the CircleCI orbs registry which is circleci/node@5.0.3. You have also configured the command to run the application's test with run:npm test.

Setting up the Project on CircleCI

Now that you've completed your CircleCI configuration, you’ll need to connect the Nest.js project to CircleCI. To do this, push your code to GitHub and set up CircleCI to detect and start builds in response to repository changes. Now, login to your CirceCI account, navigate to the left-hand side and click on the Projects tab.

Screenshot of the Projects tab on the left-hand side of the CircleCI UI.

On this page, click on the Create Project button.

Screenshot of the Projects page, showing the Create Project button.

Now, connect your GitHub account and the repository that contains the Next.Js application and CircleCI configuration.

A screenshot showing a Project setup for CI builds on CircleCI

You’ll need to create a private and public SSH key for your repository. To do this use the following command on your terminal:


Ensure you store your public and private SSH keys securely. Copy and paste your private key in the —BEGIN OPENSSH PRIVATE KEY— field. Then, choose your corresponding Repository and input a unique name in the Project Name field. Now click the Create Project button. When your project is created successfully, you’ll see a similar result to the image below.

Screenshot of a page after creating a project on CircleCI.

Now, commit a change in your code to trigger your pipeline. After that, go to your project and you’ll see a build-and-notify action with a success status on your project page.

Screenshot of a successful build-and-notify workflow of my project in CircleCI

Click on build-and-notify to view more details about your commit.

Screenshot showing full details of the build-and-notify workflow in CircleCI

Adding Slack Integration

You’ll need to integrate Slack to receive notifications about build statuses. To do this, create a Slack Workspace, and give it a unique name.  Ensure to use CircleCI as a prefix for the name of your workspace. I used CircleCI-Notifier as the name of my workspace.

Screenshot of my slack workspace—CircleCI-Notifier

Next, set up your Slack OAuth token for authentication. To do this, go to the Slack API website and click the Create an App button.

Screenshot of slack api. This shows a button for Creating an app.

On the next prompt, choose the From scratch option. After that, input the name of your app, choose the corresponding workspace you created, and click on the Create App button.

Screenshot displaying the app creation process, here it shows the name of my app and the workspace where the app will be installed

When your app has been created successfully, go to the Permissions section of your app, and scroll to the Scopes section. In the Scope section, add the following permissions:

  • chat:write
  • chat:write.public
  • files:write

Screenshot of Scopes from my app on Slack with permissions to chat:write, chat:write:public, and files:write

Next, scroll up to OAuth Tokens for Your Workspace, and click Install to Workspace.

Screenshot displaying a button to Install an app to my workspace on Slack

When you install your app successfully to your workspace, a Bot User OAuth Token will be generated. Copy and keep it safe to be used later.

Screenshot showing Bot User OAuth Token on slack api

Integrating Twilio for Notifications

To integrate Twilio for notifications, go to your Twilio account dashboard, and create a Twilio number. Then scroll down to your Account Info section. Copy your Account SID and Auth Token, and keep it safe. Also, verify your account with your main number which you’ll use to receive SMS notification from your Twilio number.

Next, go back to your project on CircleCI and navigate to the Project Settings page.

Nest notification project on GitHub

On the Project Settings page, Click the Environment Variables on the side menu. Then click Add Environment Variable, and create the following variables one after the other:

  1. TWILIO_FROM: This variable holds the value for the Twilio phone number that you created e.g. +12567555381.
  2. TWILIO_TO: This variable determines the destination phone number for your SMS message. Ensure you input your number beginning with your country code.
  3. TWILIO_ACCOUNT_SID: This variable holds the value for your Twilio Account SID.
  4. TWILIO_AUTH_TOKEN: This is your Twilio AUTH TOKEN
  5. SLACK_ACCESS_TOKEN: Token you got when you installed the app on your workspace.
  6. SLACK_DEFAULT_CHANNEL: This variable holds your channel ID as a value. To get this, navigate to your Slack workspace, and select your desired channel, e.g. #notification. While you are in this channel, click on the channel name to see the dropdown menu, then scroll down the dropdown menu to see your Channel ID.

Screenshot of created variables in the Environment Variables of my project on CircleCI,

Once you are done assigning values to the variables, go back to your project.

Now you need to open the .circleci/config.yml file and update its content with the CircleCI Twilio orb details like this:

version: 2.1
  node: circleci/node@5.0.3
  slack: circleci/slack@4.10.1
  twilio: circleci/twilio@1.0.0
      name: node/default
      - checkout
      - run:
          name: Install dependencies
          command: npm install
      - run: npm test
      - slack/notify:
          event: pass
          template: success_tagged_deploy_1
      - slack/notify:
          event: fail
          mentions: "@dibia27"
          template: basic_fail_1
      - twilio/sendsms:
          body: Successful message from Twilio
      - build-test-and-notify

In the twilio/sendsms file, there is a command used to send SMS once the build is successful, and in the mentions command, change the value to your Slack username.

Now, commit all the code changes and push them to GitHub. This will automatically trigger the build on the CircleCI UI. Once the process is completed and built successfully, you will receive the custom messages both in the channel you chose for your Slack workspace and by SMS.

Screenshot of successful deployment message in Slack channel for a successful CI build

Screenshot showing an SMS for of successful deployment message from Twilio,


In this tutorial, I've shown you how to integrate Twilio orbs from the CircleCI orb registry into  Slack with minimal code. By leveraging these orbs, you can effortlessly set up a comprehensive notification system with just a few lines of configuration. Automated notifications are essential in creating efficient CI/CD pipelines, ensuring that you stay well-informed about the status of builds and you can promptly address any issues that arise.

Udensi Fortune Arua is a DevOps Engineer, and a Technical Writer in Enugu, Nigeria, reach out on LinkedIn and Twitter to connect.