> ## 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.

# How alerts work

> An alert is a rule checked every second on the server and delivered to Telegram, the browser or Pushover. Rules watch scanner filters, a scanner page, one pair or one market metric.

Alerts need an account. Guests see a lock on **Tools › Alerts** and **Settings › Alerts**.

Two places matter:

* **Tools › Alerts** (`/tools/alerts`) lists your rules and lets you create, edit, pause and delete them.
* **Settings › Alerts** (`/settings/alerts`) holds the delivery channels and the language of messages, see [Channels](https://docs.spreader.sh/en/alerts/channels.md).

![Tools › Alerts: the list of rules.](https://mintcdn.com/develops-6bdfff15/wHoc8ymqHXCxymk7/images/alerts/list-en-dark.png?fit=max\&auto=format\&n=wHoc8ymqHXCxymk7\&q=85\&s=600dfa453bcfbeedfc238743692a1a3b)

Tools › Alerts: the list of rules.

## Kinds of rules

| Kind | What it watches | Where to create it |
| - | - | - |
| **filters** | A snapshot of scanner filters. Fires when a route newly enters them. | Scanner **Alert › Copy the current filters**, see [From the scanner](https://docs.spreader.sh/en/alerts/from-scanner.md). |
| **page** | The saved filters of a scanner page, whatever they are at that moment. | Scanner **Alert › Follow this page**. |
| **pair** | One direction of one pair: a threshold on In net, Out net, gross spreads, APR, break-even or funding spread, or a change over time. | Spread page **Alert › Spread of this pair**, see [Pair and market](https://docs.spreader.sh/en/alerts/pair-and-market.md). |
| **market** | A metric of one market, of all markets of a coin or of all markets on an exchange. | Spread page **Alert › Long market / Short market**, asset header **Alert**, Loans **Alert**, or **New alert…** on the Alerts page. |

A filters rule without In or Out bounds is treated as a **rates** rule (APR and funding) and gets quieter defaults, see [Protections](https://docs.spreader.sh/en/alerts/protections.md).

## The Alerts page

The counter reads `N of Max`. **New alert…** opens the wizard **What to watch** with **Spread or rates by filters** (points you to a scanner page) and **A market metric**. The line `engine: N rules in work` confirms the server is checking rules, `engine: waiting for the core` means delivery is paused.

| Column | Meaning |
| - | - |
| **State** | `active`, `off`, `paused: storm` (auto-pause after too many firings), `paused: page too wide`, `done` (a once rule that fired). |
| **Rule** | Name and a summary: filter chips, the pair or the market and the threshold. |
| **Kind** | filters, page, pair or market. |
| **Mode** | When a route enters, Each time it crosses, Once then switch off, Repeat while it holds. |
| **Channels** | Telegram, Browser, Pushover or `all enabled`. |
| **Fired** | Number of firings and the last one. |

Row actions: **Enable** or **Disable**, **Resume** after a pause, **Edit** (opens the same editor as creation) and **Delete**. Deleting removes the rule and its history of firings.

## Limits

| Limit | Value |
| - | - |
| Rules per account | 10 |
| Directions a filters or page rule may match | 5 000. Wider rules are refused with **narrow it** and a page rule is paused as `page too wide`. |
| Test messages per channel | 1 per 30 seconds |

Each rule can also be paused by its own **Auto-pause** protection. The bot command `/alerts` pauses and enables rules from Telegram, see [Telegram bot](https://docs.spreader.sh/en/bot/personal.md).


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