> ## Documentation Index > Fetch the complete documentation index at: https://docs.lerix.dev/llms.txt > Use this file to discover all available pages before exploring further. # Maintenance mode > Cover your app with a full-screen maintenance message, now or on a schedule, for everyone or only part of your audience. Maintenance mode puts a screen over your whole app that the user can't get past. Use it for a database migration, an outage, or any time the app shouldn't be used. It lives on the **Emergency** tab of **Release control**. ## What the user sees * Your **title** and **message**, in English or Arabic depending on the device language. * **Expected back at** followed by the end time in the device's own time zone, unless you turn it off. * A **Try again** button that checks again right away. The screen can't be dismissed. On Android, **Back** sends the app to the background instead of returning to it. On the web, the rest of the page can't be focused or clicked. The screen disappears by itself as soon as the window ends or you end it. If you leave the copy empty, the defaults are: | | English | Arabic | | - | - | - | | Title | We'll be right back | سنعود قريباً | | Message | The app is under maintenance. Please try again later. | التطبيق تحت الصيانة حالياً. يرجى المحاولة لاحقاً. | ## Start a maintenance window **1. Open the dialog** Click **Maintenance mode** on the **Emergency** tab. The dialog **Turn on maintenance mode** opens. **2. Who sees it** Pick the scope (see [Scope](#scope)). Leave a field empty to include everyone. **3. Screen** Title and message in English and Arabic, and whether to **Show “Expected back at …” on the screen**. **4. When** **Start now**, or **Schedule** a start time up to 30 days ahead. Choose when it ends (1 hour to 7 days, see [Automatic end](#automatic-end)). **5. Allow-list (optional)** Let your team through, or test the screen on your own devices first (see [Allow-list and test mode](#allow-list-and-test-mode)). **6. Confirm** Review who will be locked out, give a reason (3 to 500 characters), type the project slug, and click **Turn on maintenance** or **Schedule maintenance**. While a window is on, a red **Maintenance mode is ON** banner shows on both tabs of **Release control**. ## Scope | Field | Matches | | - | - | | **Platforms** | iOS, Android, macOS, Windows, Linux, web. None selected means every platform. | | **Environment** | One environment, `prod` by default. | | **Only these versions** | Exact app versions, such as `3.2.0`. | | **Versions below** | Every version lower than this one. `3.2.0` covers `3.1.x` and older. | | **Countries** | Two-letter country codes, found from the device's IP address. A device whose country is unknown never matches a window that lists countries. | With both version fields empty, every version matches, including devices that didn't report one. When either is set, a device without a version doesn't match. The scope can't be changed once the window exists. To change it, end the window and start a new one. ## Scheduling A scheduled window shows as **Scheduled** under **Active and scheduled**, with a countdown, and starts by itself at its start time. Devices learn about it up to 24 hours before it starts and keep it to themselves until then, so it begins on time even on a device that has gone offline in the meantime. **Cancel** removes a scheduled window before it starts. ## Automatic end Every window has an end time, so a forgotten window can't lock users out for good. * By default it ends 24 hours after it starts. * You can set it up to 7 days after the start. * A device that saved the window ends it on its own at the end time, even with no network. **Extend** moves the end time later (+1 hour, +4 hours, +24 hours or a time you pick), within the same 7-day limit. ## Allow-list and test mode The **Allow-list** holds the people and devices the window treats differently, one ID per line: * **External user IDs**: the IDs you pass to `setUser` (see [Identify users](https://docs.lerix.dev/modules/users-identity.md)). * **Install IDs**: single installations of your app, such as your test phones. * **Lerix user IDs**: the IDs Lerix gives each registered device. By default, devices on the allow-list are never blocked, so your team can keep using and checking the app. Turn on **Test on allow-listed devices only** to do the opposite: the window applies **only** to devices on the list (it needs at least one). Use it to see the real screen, with your real copy, on your own phone before anyone else does. ### Go live When the test looks right, click **Go live** on the window. Test mode turns off and every device in scope sees the maintenance screen within a minute. You can also edit the copy, the expected end time and the allow-list of a running window. ## End a window * **End now** ends one window. Devices drop the screen at their next check, which is within about a minute for apps in the foreground. * A window also ends by itself at its end time. ### Lift all **Lift all** is the undo button for when something went wrong and users must get back into the app now. One click: * ends every scheduled and active maintenance window, and * turns off every forced-update rule (a minimum version or build, a blocked version, or a deadline). Optional and recommended update prompts stay as they are. The confirmation shows how many windows it will end and how many rules it will turn off, and asks for a reason. ## How fast devices react When you start, change or end a window, or use **Lift all**: 1. Lerix sends a silent push to every device of the project that has a Lerix push token, at most once a minute. Apps in the background refresh without showing anything to the user. A scheduled window starting or ending by itself sends the push too. 2. For the next 30 minutes, apps in the foreground check every minute. 3. While a window applies to a device, or starts within the hour, that device keeps checking every minute. Web pages, and apps that don't set up Lerix push notifications, don't get the silent push. They rely on the one-minute checks and on checking when the app or tab comes back to the foreground. See [Delivery and offline behaviour](https://docs.lerix.dev/modules/release-control/delivery-offline.md). ### Propagation meter **Propagation**, on the **Emergency** tab, shows how many devices have picked up your latest change, for example "1,830 of 2,240 active devices have the latest config (82%)". * **Active devices** are those seen, or that checked release control, in the last 24 hours. * A device counts as updated once it has fetched the configuration after your last change. * Only devices that identify their user to Lerix are counted. ## History and alerts Every start, edit, end and **Lift all** is recorded in **History**, with who did it, when, the reason, and the values before and after. Windows that start or end on schedule are recorded too, by **System**. Project members who can manage app updates get an in-app notification and an email when a window is turned on or scheduled, starts on schedule, goes live, or ends, and when someone uses **Lift all**. Each member can turn the email off in their notification preferences. See [Events, webhooks and permissions](https://docs.lerix.dev/modules/release-control/events-webhooks.md). This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.