Overview 

The notifications_slack TYPO3 extension provides the slack channel for Lex Notifications. It converts a notification's toSlack() result into an HTTPS request using TYPO3's HTTP RequestFactory.

Features 

  • Slack Incoming Webhooks on approved HTTPS hosts.
  • Slack Web API chat.postMessage with a Bot Token.
  • GovSlack webhook hosts and API endpoint configuration.
  • Plain text and Slack mrkdwn content.
  • Legacy Slack attachments.
  • Block Kit from slack-php/slack-block-kit objects.
  • Raw Block Kit Builder JSON (including top-level block arrays).
  • Thread replies and optional reply broadcasting.
  • Integration with the core's on-demand, model-based, and queued delivery.
  • HTTP rate-limit/error reporting without automatic transport retries.

What this extension does not provide 

This is a delivery channel, not a general Slack client. It does not create Slack applications, manage OAuth installation, upload files, process interactive Slack callbacks, or subscribe to Slack events.

Message delivery requires an explicitly configured route. The notification core evaluates routeNotificationFor('slack', ...) before calling SlackChannel; setting a destination inside the message is neither supported nor sufficient.

Technical identifiers 

Item Value
Composer package agencelex/notifications-slack
TYPO3 extension key notifications_slack
Channel name slack
PHP namespace Lex\\Notifications\\Slack
Core dependency agencelex/notifications:^1.5
Block Kit dependency slack-php/slack-block-kit:^2.3

Next: install the extension.