# Connect Slack to notifications > To receive Invunion notifications in Slack, you create an incoming webhook in Slack, copy its URL, and paste it in the Recipients part of a notification rule. This guide walks through each step, from creating the Slack app to sending a test message, and explains what to do when the message does not arrive. Source: https://www.invunion.com/knowledge-base/connect-slack/ Last updated: 2026-10-13 Invunion sends its messages to a Slack channel through a Slack **incoming webhook**. A webhook is a private web address that belongs to one channel. Anything Invunion posts to it appears in that channel. You do the first part in Slack, the second in Invunion. It takes about five minutes. **Before you start** - You can add apps to your Slack workspace. If you cannot, ask a Slack admin to follow the steps in Part 1 for you. - You can edit notification rules in Invunion. See [Notifications](https://www.invunion.com/knowledge-base/notifications/). ## Part 1: create the webhook in Slack You create a small Slack app from a ready-made block of settings. Copy the block, paste it, and do not change anything in it. 1. Open [api.slack.com/apps](https://api.slack.com/apps) and select **Create New App**. The Slack API Your Apps page with the Create New App button at the top right 2. Choose **From a manifest** and select **Continue**. The Create new app dialog in Slack with the From a manifest option selected 3. Make sure the **JSON** tab is selected. Delete all the text in the box, select **Copy** on the block below, and paste it in its place. ```json { "display_information": { "name": "Invunion Notifications", "description": "Payment and invoice notifications from Invunion" }, "features": { "bot_user": { "display_name": "Invunion Notifications", "always_online": false } }, "oauth_config": { "scopes": { "bot": [ "incoming-webhook" ] } }, "settings": { "org_deploy_enabled": false, "socket_mode_enabled": false, "token_rotation_enabled": false } } ``` The Create from a manifest dialog in Slack with the JSON tab open and the default Demo App text, to be replaced 4. Scroll down, choose your workspace, and select **Next**. The Create from a manifest dialog in Slack with the workspace Invunion selected and the Next button 5. Check the summary and select **Create and Install**. The Review your app step in Slack with the Create and Install button 6. Under **Channel for webhook**, choose the channel that should receive the messages, for example `#finance`, and select **Allow**. The Slack page that asks to allow the Invunion Notifications app, with the workspace and the Channel for webhook chosen and the Allow button 7. In the left menu, select **Incoming Webhooks**. Select **Copy** next to the webhook URL. The Incoming Webhooks page in Slack with the Incoming Webhooks item selected in the left menu and an arrow pointing to the Copy button next to the webhook URL The app only has one permission: posting messages in the channel you chose. The URL starts with `https://hooks.slack.com/services/`. Treat it like a password: anyone who has it can post in that channel. ## Part 2: add the channel to a notification rule 1. In Invunion, open **Settings > Administration > Notifications**. 2. Select **Add notification**, or edit an existing rule with the pencil icon. 3. Choose the events, the timing and the filters of the rule. 4. In **Recipients**, select **Slack**. 5. Paste the URL in the **Slack webhook URL** field. 6. Select **Save**. The recipients part of the notification rule form with the Slack webhook URL pasted in the field After saving, the rule card shows **Slack** with the last four characters of the URL. Invunion stores the URL encrypted and never shows it again. To replace it, edit the rule and paste a new one. ## Part 3: check that it works Select the **Send test** icon on the rule card. A test message arrives in the Slack channel within a few seconds. If nothing arrives, open the rule's **History**. Each message shows its status: pending, sent, failed, or skipped. ## If it does not work | What you see | Why | What to do | | --- | --- | --- | | Invunion refuses the URL when you save | Invunion only accepts Slack webhook addresses, which start with `https://hooks.slack.com/`. | Copy the URL again from the Incoming Webhooks page. | | The test is marked failed | Slack could not be reached. Invunion retries 5 times, after 1, 4, 16 and 64 minutes. | Wait for the retries, then check **History** again. | | The Slack part of the rule stops sending | If Slack answers that the webhook is forbidden, not found or gone, Invunion disables it. This happens when the app or the webhook was deleted. | Create a new webhook in Part 1, edit the rule and paste the new URL. | | The message goes to the wrong channel | A webhook is tied to the channel you chose in step 6. | Create a new webhook for the right channel and replace the URL. | ## Good to know - One rule can post to several channels. Select **Slack** again to add another URL. - The message wording is the same as for email and Teams. You can change it in **Customize the message**. - To remove the connection, delete the Slack line from the rule, or delete the app in Slack.