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
- In Mattermost, open the Main Menu > Integrations > Incoming Webhooks.
- Select Add Incoming Webhook, give it a title and pick the channel it posts to.
- 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
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.