Quick Start

Before starting with the Omni API, follow the checklist below.

  1. Create an Omni account
  2. Subscribe to the Omni Status Page
  3. Build
  4. Go Live

Create an Omni sandbox account

Click the button that applies to you below to create an Omni sandbox.

Note: Creating an Omni sandbox will subscribe you to receive emails from Fattmerchant. You can opt out later.

Developers ISV Partners

Once you have created your sandbox, you will have an Omni account with an API key, ready for testing. Follow the steps below to get started

  1. Log into Omni
  2. Find the sandbox in your merchant switcher in the upper right hand corner
  3. Find the api key here (Omni -> apps -> Api Keys)
  4. To access the API when using a live or sandbox API key, you will use the same production URL: however, your sandbox will be linked to a test gateway and will not use real money
  5. There are specific card numbers you can use when using a sandbox account - documented in the payment methods resource.

Subscribe to Omni’s Status Page


Subscribe to the Omni’s status page to see API updates and scheduled maintenance alerts.


When you are ready to start implementing payments, head over to the Libraries & SDKs documentation to decide which resource you need.

Libraries & SDKs

Go Live

Once you are ready to process live payments, you will need to create a production account in Omni. Creating a production account does require our underwriting team to first approve the account.

To apply for a production account:

  1. Log in to Omni
  2. Select the account name in the top right corner
  3. Click Add Location
  4. To copy the account information over, click “Clone”. Alternatively, you can click “Create New”
  5. Once your account has been submitted, underwriting will begin and a member of the Fattmerchant team will be in touch

Once your account is approved, you will need to log in to your production account to obtain your product API credentials

Log in to your production account:

  1. Log in to Omni
  2. Select your production account from the dropdown in the top right corner
  3. Click Apps from the navigation
  4. Click API keys
  5. Click Launch
  6. Click “+ New Key”
  7. Copy your API Key
  8. If using Fattmerchant.js, you will also need to copy your Web Payments Token