Slack

Overview

The Slack connector installs a Tessel app in your workspace. Workflows post Block Kit messages to the channels you pick, and approval steps send buttons to a named person and their backup. When someone taps Approve or Reject, the run continues in under half a second and the decision lands in the trace.

Teams use it to approve Stripe refunds above a threshold, to post failed NetSuite syncs to a finance channel and to let support leads start a workflow with a slash command.

Event coverage

• Interactive button clicks on approval messages

• Messages in public and private channels the app is invited to

• Slash commands registered by the Tessel app

How approvals work

An approval step posts a message with Approve and Reject buttons, threaded under the run summary. Slack sends the click to Tessel as a block_actions payload, which Tessel checks against the request signature and the approver list. Anyone else who taps a button gets a private note instead.

approval:
  channel: "#finance-approvals"
  approver: "@dana"
  backup: "@lee"
  timeout: 4h
  on_timeout: reject

approval:
  channel: "#finance-approvals"
  approver: "@dana"
  backup: "@lee"
  timeout: 4h
  on_timeout: reject

approval:
  channel: "#finance-approvals"
  approver: "@dana"
  backup: "@lee"
  timeout: 4h
  on_timeout: reject

Timeouts

If nobody answers before the timeout, Tessel pings the backup once, then applies the fallback you set. The message updates in place so the channel always shows the current state.

Permissions needed

Install the app with the bot scopes below. It only reads channels it is invited to, and it never reads direct messages. Approvers are matched by Slack user ID, not display name.

• chat:write to post and update messages

• channels:history and groups:history for message triggers

• commands for slash commands