---
description: Send Report URI Watch alerts to a Mattermost channel using a Slack-compatible incoming webhook.
---

# Mattermost

Mattermost incoming webhooks are deliberately Slack-compatible and accept a `{"text": "..."}` body, which is the shape our payload carries. Nothing has to be translated, and self-hosted Mattermost means the alert never leaves infrastructure you control - which matters if your findings are themselves sensitive.

## Creating the webhook URL

1. In Mattermost, open the **Main Menu > Integrations > Incoming Webhooks**.
2. Select **Add Incoming Webhook**, give it a title and pick the channel it posts to.
3. Save, and copy the generated URL.

It looks like:

    https://your-mattermost-server.com/hooks/xxx-generatedkey-xxx

## Sending alerts to Mattermost

Open the **Config** modal on the watcher you want alerts from, enable **Send Webhook alerts**, and paste the URL into **Target webhook URI**.

## Things to watch for

- **Incoming webhooks may be disabled on your server.** They are controlled by a System Console setting, and on a locked-down instance an administrator has to enable them before the URL will work at all.
- Your Mattermost server has to be reachable from the internet for us to post to it. An instance behind a VPN with no ingress will never receive an alert, and the failure looks like silence.
- The webhook URL is a secret - anyone holding it can post to your instance.
- If your server enforces an allow-list of channels per webhook, make sure the target channel is on it.

## Official documentation

[Mattermost - Incoming webhooks](https://developers.mattermost.com/integrate/webhooks/incoming/)

## Start Monitoring with Report URI

**Already using us?** Create the incoming webhook, then paste its URL into any watcher's Config modal.

**New to Report URI?** Watch products and webhooks are available on Business plans and higher.

[Start your free trial](https://report-uri.com/register/?plan=starter2025)