Connect Trello to Slack

What This Integration Does

This integration posts Trello card activity into Slack with per-board channel routing, per-list message formatting, and smart filtering. Card creation, list moves, due-date alerts, checklist completions, and member assignments all post into Slack with formatting that matches how the team actually works, rather than the undifferentiated stream the default power-up produces.

The Workflow

When a card is created or moved between lists, the integration receives the webhook, finds the configured channel for the board, and posts a message describing the change. A card moving from “In Progress” to “Review” posts to the channel tagging the reviewer assigned to the card. A card moving to “Done” posts a confirmation with the elapsed time from creation.

Due-date approaching alerts fire when a card with a due date is two working days out and hasn’t moved into the “In Progress” or “Done” lists.

Here is a concrete example. A content marketing team runs a Trello board with “Idea,” “Brief,” “Drafting,” “Editing,” “Scheduled,” and “Published” lists. A card moves from “Drafting” to “Editing.” The integration posts to the #content channel tagging the editor with the working title, the writer’s name, and a link to the card. Two days later, if the card has not moved to “Scheduled,” a follow-up alert posts. When the card finally reaches “Published,” the integration posts a closing message in the channel with the published URL pulled from a custom field on the card, and tags the writer and editor.

Checklist completions also surface. A board configured with launch checklist cards posts a progress update each time an item is ticked, showing the percentage complete and the next item due.

Before and After

Before, Trello’s built-in Slack power-up posts updates into a single channel that nobody reads. Important moves get lost. Due-date misses go unannounced. The team checks Trello manually and ignores the Slack signal entirely.

After this integration is in place, each board has its own channel. Card moves carry enough context to act on, due-date alerts land before things slip, and the team trusts the Slack signal rather than working around it.

Who Needs This

Small teams and agencies using Trello as the operational system, particularly content teams, marketing teams, and product teams who like Trello’s simplicity and run their work as kanban. The integration becomes worthwhile once boards have grown beyond a few cards a week and the native notifications have become noise rather than signal.

How We Build This

We build this against the Trello REST API and the Slack Web API. Trello webhooks fire on card, list, board, and checklist changes; the integration filters and routes each event according to per-board configuration. See Slack API Integration for the Slack capabilities involved. This build is part of the broader workflow integrations catalogue, which includes similar channel-routing builds for Notion and Slack and Asana and Slack.

Get Trello and Slack Connected

If your team works in Trello and coordinates in Slack and the default integration is producing noise instead of signal, we can build a custom routing layer that delivers the right card update to the right channel.