> For the complete documentation index, see [llms.txt](https://docs.n8n.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.n8n.io/integrations/builtin/credentials/msg91.md).

# MSG91 credentials

You can use these credentials to authenticate the following nodes:

* [MSG91](/integrations/builtin/app-nodes/n8n-nodes-base.msg91.md)

## Prerequisites <a href="#prerequisites" id="prerequisites"></a>

Create a [MSG91](https://msg91.com/) account.

## Supported authentication methods <a href="#supported-authentication-methods" id="supported-authentication-methods"></a>

* API key

## Related resources <a href="#related-resources" id="related-resources"></a>

Refer to [MSG91's API documentation](https://docs.msg91.com/overview) for more information about the service.

## Using API key <a href="#using-api-key" id="using-api-key"></a>

To configure this credential, you'll need:

* An **Authentication Key**: To get your Authentication Key, go to the user menu and select **Authkey**. Refer to MSG91's [Where can I find my authentication key? documentation](https://msg91.com/help/api/where-can-i-find-my-authentication-ke) for more information.

## IP Security <a href="#ip-security" id="ip-security"></a>

MSG91 enables [IP Security](https://msg91.com/help/api/what-do-you-mean-by-api-security) by default for authkeys.

For the n8n credentials to function with this setting enabled, add all the [n8n IP addresses](/deploy/use-n8n-cloud/configure-cloud/find-your-ip-addresses.md) as whitelisted IPs in MSG91. You can add them in one of two places, depending on your desired security level:

* To allow any/all authkeys in the account to work with n8n, add the n8n IP addresses in the **Company's whitelisted IPs** section of the **Authkey** page.
* To allow only specific authkeys to work with n8n, add the n8n IP addresses in the **Whitelisted IPs** section of an authkey's details.