> ## Documentation Index
> Fetch the complete documentation index at: https://launchdarkly.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Kill switch flags
This topic explains how you can use kill switch or circuit breaker flags to shut off functionality. These flags are permanent safety mechanisms that you can use to turn off non-core functionality or third-party tools in an emergency.
## About kill switch flags
Kill switch flags, sometimes called circuit breaker flags, are permanent boolean flags with two variations: "Enabled" (true) and "Disabled" (false).
Kill switch flags are operational flags that control or change how your app or service operates. Often, these changes happen in response to unplanned events, such as traffic spikes or third-party service failures. You can use these flags to quickly turn off functionality when needed. You can also integrate these flags with observability or application performance management (APM) tools to automate flag shut off. To learn more, read [Monitoring tools](/docs/integrations/monitoring).
## Create kill switch flags
To create a kill switch flag:
1. Click **Create** and choose **Flag**. The "Create flag" dialog appears.
2. Enter a unique, human-readable **Name**. A suggested key auto-populates from the name you enter, but you can customize it if you wish.
3. (Optional) Click **Edit key** to update the flag key. You'll use this key to reference the flag in your code.
4. (Optional) Enter a **Description** of the flag. A brief, human-readable description helps your account members understand what the flag is for.
5. (Optional) Click **Custom** and select **Kill switch**.
6. (Optional) Change the [default on](/docs/home/flags/default-rule) and [default off](/docs/home/flags/off-variation) variations if needed.
7. (Optional) Click on your member name to change the flag maintainer.
8. (Optional) Click the **tag** icon to add one or more [tags](/docs/home/account/tags).
9. (Optional) Click the **views** icon to add the flag to a [view](/docs/home/account/views).
10. (Optional) Click **All SDKs** to make the flag [unavailable to client-side or mobile SDKs](/docs/home/flags/flag-settings). Flags are available to all SDKs by default.
11. Click **Temporary** to change the flag from [temporary to permanent](/docs/home/flags/flag-settings).
12. Click **Create flag**.
The flag **Targeting** tab appears.
After you create a flag, you can make further changes to it as needed, such as to [update flag targeting](/docs/home/flags/target).
To learn more, read [Creating new flags](/docs/home/flags/new).
Because kill switch or circuit breaker flags are used to shut off functionality or third-party tools completely, they typically do not use complex targeting rules. Instead, they serve "Enabled" by default when targeting is on, and "Disabled" when targeting is off. To learn more about targeting, read [Target with flags](/docs/home/flags/target).
## Modify the kill switch flag template
To modify your kill switch flag template:
1. Click the project dropdown. The project menu appears:
2. Select **Project settings**.
3. Select **Flags**. The **Flags** settings list appears.
4. In the "Flag templates" section, click the **pencil** icon next to "Kill switch."
5. Choose **Yes** or **No** to mark all kill switch flags as temporary or permanent. Kill switch flags are usually permanent.
6. In the "Variations" section, edit the flag variation **Names**.
7. In the "Default variations" section, choose which default variations to serve when the flag is toggled **On** or **Off**.
8. In the "Tags" section, type to add tags to each new flag by default.
9. Click **Save**.
Verify that the updated default template settings are correct by navigating to the **Flags** list and creating a new kill switch flag.