---
title: What goes into Slack — and what never leaves
description: "Seven notifications can reach Slack, and only one thing reaches a channel: counters. Here is the exact rule, and why it is fail-closed. - **Read**5 min - **Level**Intermediate - **Updated**September 2026 - **Module**Integrations & API ## The principle A Slack…"
url: "https://illizeo.com/en/centre-aide/what-goes-into-slack/"
updated: "2026-10-16"
category: "Platform / Integrations & API"
---

# What goes into Slack — and what never leaves

Seven notifications can reach Slack, and only one thing reaches a channel: counters. Here is the exact rule, and why it is fail-closed.

- **Read**5 min
- **Level**Intermediate
- **Updated**September 2026
- **Module**Integrations & API

## The principle

A Slack channel is readable by the whole workspace, external guests included. A sick-leave absence posted into a team channel is not a display glitch, it is a data-protection incident. The connector starts from there: **everything is a direct message by default**, and whatever reaches a channel is reduced to counters.

| Message type | Destination | Content |
| --- | --- | --- |
| Individual HR notification | Direct message to the employee | The fact, and an *Open in Illizeo* button |
| Absence request to approve | Direct message to the approver | The requester, the absence type, Approve / Reject buttons |
| HR digest | Channel chosen by the administrator | Two counters, no names |

## The seven notifications that can reach Slack

- Approvals: absence request, expense report, attendance — and the outcomes (accepted, rejected, ready for payment)
- Document to validate
- Meeting scheduled or cancelled
- @-mention in a thread
- On-call
- Onboarding and offboarding to-dos
- Payroll review reminder

No other Illizeo notification goes to Slack. And these only go there if the employee has ticked Slack for that event: the setting is zero by default, and a missing settings row does not switch it on either. The message goes out in the *recipient’s* language, like emails.

## Approving an absence from Slack

An absence or certificate request that is **still pending** arrives with two buttons, Approve and Reject, alongside the open button. The decision is recorded in Illizeo exactly as if it had been taken on screen.

Three safeguards: the request coming from Slack is authenticated by signature; a request whose timestamp is more than five minutes old is refused even with a correct signature; and the same click redelivered by Slack is processed only once.

Expense reports and attendance do not get those buttons: they open in Illizeo.

## The HR digest

The only message meant for a channel. It carries two counters: the number of pending requests and the number of employees absent today — the same definition of “absent today” as the dashboard. The administrator picks the channel and the frequency, daily or weekly. With no channel chosen, nothing is posted: no guessed channel, no unrequested noise.

## The rule: never a name or an amount in a channel

Before any channel send, the message is inspected. If it carries an **identity** (name, email, requester, approver, signer, reason, document…) or an **amount** (salary, total, reimbursement, cap, currency…), the channel is refused and the message does not go there. The rule is fail-closed: an event that is not explicitly allowed goes out privately. Exactly one event is allowed in a channel today, the HR digest.

Amounts never leave at all — channel or not. An approved expense report announces the approval in Slack; the sum stays in the email.

## What does not exist

No slash command, no conversational bot, no Illizeo search from Slack. No automatic posting of joiners, leavers, birthdays or project milestones into a channel. No frequency other than daily or weekly for the digest. No Microsoft Teams connector.

## FAQ

   Why is my Slack message shorter than the email?

Because amounts are stripped from it, and because it aims at the action: the detail sits behind the button.

   Can the digest name who is absent?

No, by construction. A digest that named someone would no longer be an aggregate: it would be pushed back to a direct message rather than posted.

   What if I click Approve twice?

The second processing is ignored. Slack itself sometimes retries a delivery; the protection covers that case too.

   Do managers see their team’s absences in a channel?

No. A channel only receives counters. Individual requests arrive as a direct message to the approver concerned.

   What if the employee is not on Slack?

The message goes out by email. The connector never redirects a direct message to a channel to compensate: guessing a recipient for personal data would be worse than sending nothing.

### Configure notifications and reminders

The three available channels, and how to set them event by event.

[See all Platform articles](/en/centre-aide/?cat=platform)

### *Related*