<!-- source: https://docs.codemagic.io/knowledge-others/slack-api-integration/ -->
<!-- last modified: 2022-11-23 -->

# Custom Slack Integration with Codemagic

> How to customize slack messages for codemagic builds

Customize Slack notifications for publishing into your Codemagic build pipeline by building a Slack app from scratch via webhooks.

### Step 1: Create a new Slack App

To create a new Slack app, go to the Slack app settings page [here](https://api.slack.com/apps). **Create new App > From scratch**

![Start from scratch](../uploads/choose-scratch-option.png)

Give it a name for e.g. **Codemagic CI/CD** and select the workspace of your choice to install the app.
Click create App.

![Create a new slack app](../uploads/create-new-slack-app.png)

Go to you **App settings > Basic Information > Display Information** and fill all the general details.

![Create a new slack app](../uploads/general-info.png)

### Step 2: Add a new webhook to the slack app.

You will see that the newly created app is added and visible under App settings page [here](https://api.slack.com/apps). Select the App, it will take you to a dedicated app settings page. **Activate** the Incoming webhook request.

![Create a new slack app](../uploads/incoming-webhooks.png)

Navigate to **Incoming Webhooks > Add new webhook to the workspace**. This will generate the webhook url. Copy the webhook url and add it as an ENV variable e.g. SLACK_WEBHOOK_URL.

![Create a new slack app](../uploads/webhooks-permission.png)

### Step 3: Setting required variables.

Codemagic exports several built-in environment variables during the build that you can use in scripts to customize the build process. You can refer to the documentation [here](../variables/environment-variables/)

For our example, we will be passing the below variables for our custom slack integration.

1. $CM_BUILD_ID - UUID of the build
2. $CM_BRANCH - The current branch being built, for pull requests it is the source branch
3. $CM_REPO_SLUG - The slug of the repository that is currently being built in the form `owner_name/repository_name`. Unset for repositories added from custom source
4. $CM_COMMIT - Commit hash that is currently being built by Codemagic, for pull request builds it is the hash of the source commit.
5. $CM_PROJECT_ID - UUID of the project that is being built
6. $ARTIFACT_URL - Android Artifact Link


```yaml

ARTIFACT_URL=$(echo $CM_ARTIFACT_LINKS | jq -r '.[] | select(.name | endswith("'".apk"'")) | .url')

```


### Step 4: Create the JSON Payload

Navigate to Slack Block Kit builder [here](https://app.slack.com/block-kit-builder) to create a template or you can use the below reference template. You need to substitute the variables in the JSON Payload as shown below.


```json

{
  "attachments": [
    {
      "blocks": [
        {
          "type": "section",
          "text": {
            "type": "mrkdwn",
            "text": "Build with build id <https://codemagic.io/app/'"$CM_PROJECT_ID"'/build/'"$CM_BUILD_ID"'>"
          }
        },
        {
          "type": "divider"
        },
        {
          "type": "section",
          "block_id": "section567",
          "text": {
            "type": "mrkdwn",
            "text": "<https://github.com/'"$CM_REPO_SLUG"'> Merge pull request"
          }
        },
        {
          "type": "divider"
        },
        {
          "type": "section",
          "text": {
            "type": "mrkdwn",
            "text": "*Android Artifact Link* <'"$ARTIFACT_URL"'|Download>"
          }
        },
      ]
    }
  ]
}

```


### Step 5: Making the cURL Request

You can specify the JSON Payload in your post processing script, if you are using the workflow editor or add it as script step in the `publishing` section in your workflow if you are using yaml.


```yaml

publishing:
  scripts: 
    - name: Publish to Slack
      script: | 
        ARTIFACT_URL=$(echo $CM_ARTIFACT_LINKS | jq -r '.[] | select(.name | endswith("'".ipa"'")) | .url')
        
        curl -0 -v -X POST $SLACK_WEBHOOK_URL \
        -H 'Content-type: application/json' \
        --data-raw '
        {
          "attachments": [
            {
              "blocks": [
                {
                  "type": "section",
                  "text": {
                    "type": "mrkdwn",
                    "text": "Build with build id <https://codemagic.io/app/'"$CM_PROJECT_ID"'/build/'"$CM_BUILD_ID"'>"
                  }
                },
                {
                  "type": "divider"
                },
                {
                  "type": "section",
                  "block_id": "section567",
                  "text": {
                    "type": "mrkdwn",
                    "text": "<https://github.com/'"$CM_REPO_SLUG"'> Merge pull request"
                  }
                },
                {
                  "type": "divider"
                },
                {
                  "type": "section",
                  "text": {
                    "type": "mrkdwn",
                    "text": "*Android Artifact Link* <'"$ARTIFACT_URL"'|Download>"
                  }
                },
              ]
            }
        ]
      }'

```