> ## Documentation Index
> Fetch the complete documentation index at: https://docs.spreader.sh/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Spreader is a web service that tracks arbitrage spreads between crypto exchanges. This documentation covers only what a user of the service sees and does.
> Page paths starting with /en/ are English. Translations live under /ru/ and /uk/ with the same file names.
> Screenshots are illustrations. Every screenshot is accompanied by text that states the same facts, so you do not need to see the image.

# Alerts from the scanner

> Create a spread or rates alert from a scanner page: copy the current filters as a snapshot or follow the page so the rule tracks its saved filters. Fire per coin or per route.

The **Alert** button at the top right of a scanner page offers two items.

![Alert menu with Copy the current filters and Follow this page](https://mintcdn.com/develops-6bdfff15/0-2fZCEZBOlAqgr4/images/scanner/alert-menu-en-dark.png?fit=max\&auto=format\&n=0-2fZCEZBOlAqgr4\&q=85\&s=a5d6f9da27c34234dca29e8a13a8149a)

The Alert menu of a scanner page.

## Copy the current filters

1. Set the filters on the page, including unsaved changes.
2. Click **Alert › Copy the current filters**.
3. In the editor **Alert by filters** give the rule a **Name**, check the filter chips, pick **Fire per** and the protections, choose **Deliver to** and click **Create**.

The filters are a snapshot. To change them later, create a new alert from the scanner.

## Follow this page

1. Click **Alert › Follow this page**. With unsaved changes the hint says **Tracks the saved filters. Unsaved changes apply after Save**.
2. Fill the editor **Alert that follows a page** and click **Create**.

The rule follows the saved filters of the page: change them on the page and click **Save**. The rule is listed as `follows page "name"`. Deleting the page deletes the rule. A followed shared scanner updates the rule when its owner saves, see [Sharing scanners](https://docs.spreader.sh/en/scanner/sharing.md).

## Fire per

| Choice | Behaviour |
| - | - |
| **coin** (default) | One alert when the first route of a coin enters the filters. Other routes of that coin stay silent until the coin leaves the filters entirely. |
| **route** | An alert for every route that newly enters the filters, several per coin are possible. |

## Too wide

A rule that matches more than 5 000 directions is refused: **The filter matches N directions — narrow it to at most 5 000 (for example, set a minimum In net)**. A page rule whose page grows past the limit is paused as `paused: page too wide` until the page is narrowed.

## What the message says

A spread alert names the coin, the kind and both legs with exchange and market type, In net, Out net, APR and funding, and carries a link to the spread page. Hidden assets and pairs hidden on the page are not reported.


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