Problem

The Slack webhook implementation documentation contains two bugs in the example app.js code that prevent messages from being sent to Slack:

1. ReferenceError: body is not defined (Line 118)

In the slackMessage object, the code uses:

text: body,

However, the variable body is never defined. The extracted variable from the request is body_markdown (defined on line 92). This causes a ReferenceError when the code runs.

Fix: Change line 118 to:

text: body_markdown,

2. Invalid header block text type (Line 122)

The header block uses an invalid text type:

{
    type: "header",
    text: { type: "mrkdwn", text: title_markdown },
},

According to Slack's Block Kit API, header blocks only support plain_text as the text type, not mrkdwn. This causes the Slack API to reject the message with error: "must be a valid enum value [json-pointer:/blocks/0/text/type]"

Fix: Change line 122 to:

text: { type: "plain_text", text: title_markdown },

Impact

These errors prevent the webhook from successfully sending notifications to Slack users, making the feature non-functional.

Proposed Solution

Update the documentation at docs/admin/monitoring/notifications/slack.md with the corrected code examples.