# Overview

For each API Key, you can optionally specify which IP addresses are allowed to make requests. Modern Treasury will reject any IP addresses that are not included in the allow list.

# 1. Create or edit an API Key

Navigate to Developers > [API Keys](🔗). Here you can either create a new API key or edit an existing one.

# 2. Add IP address

When viewing an API key form, you will see a section for "Allowed IPs." Click the "Add" button in this section and add an IP address. You can add one or more IP addresses.

# 3. Save

Save the changes. Modern Treasury will immediately start adhering to the changes made in the IP allow list.