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The following example activity script posts a message to a Slack channel every time it’s triggered. To use it, follow these steps:
  1. In your Slack administrative interface, create a new Slack webhook. You get a URL starting with https://hooks.slack.com/.
  2. Replace SLACK_URL in the following script with your webhook URL.
  3. Paste the code into a .js file.
  4. Add it as a new script integration. Specify which events should trigger it using the --events flag. Optionally specify environments with the --environments flag.
Now, any activities that meet the events/environment criteria you specified are reported to Slack. Once you have it working, you’re free to modify the code below as desired. For formatting more complex messages, see the Slack messaging documentation. 
/**
 * Sends a color-coded formatted message to Slack.
 *
 * To control what events trigger it, use the --events switch in
 * the Upsun CLI.
 *
 * @param {string} title
 *   The title of the message block to send.
 * @param {string} message
 *   The message body to send.
 */
function sendSlackMessage(title, message) {
  const url = SLACK_URL;

  if (!message) {
    // No message. Don't send it.
    return;
  }

  const messageTitle =
    title + ((new Date().getDay() === 5) ? " (On a Friday! :calendar:)" : "");

  const color = activity.result === "success" ? "#66c000" : "#ff0000";

  const body = {
    attachments: [
      {
        title: messageTitle,
        text: message,
        color: color,
      },
    ],
  };

  const resp = fetch(url, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
    },
    body: JSON.stringify(body),
  });

  if (!resp.ok) {
    console.log("Sending slack message failed: " + resp.body.text());
  }
}

sendSlackMessage(activity.text, activity.log);
Common properties you may want to send to Slack (in the last line of the script) include:
  • activity.text: A brief, one-line statement of what happened.
  • activity.log: The complete build and deploy log output, as it would be seen in the Console log screen.
For more properties, see the activity reference.
Last modified on March 11, 2026