Use this article to troubleshoot Kustom Checkout when it does not load, including 401 Unauthorized errors in your API call logs, and to find out what information to send Kustom support if you need help.
For full technical details about the Kustom API, see docs.kustom.co.
Where to find your API call logs
Your API call logs show every request between your store and Kustom, including any error messages. You can find them in the Kustom Portal under Developers, in the developer logs. See Developer logs for how to search and read them.
401 Unauthorized error
A 401 Unauthorized error in your API call logs means Kustom did not accept the API credentials your store sent. This usually happens when the credentials are wrong, or when they belong to a different environment.
Kustom has two separate environments, each with its own API credentials:
Production. Your live store, where customers make real payments.
Playground. The test environment, where you test your integration without real payments. See Playground Account.
Production credentials only work in production, and Playground credentials only work in Playground.
How to fix a 401 Unauthorized error
Check that your store uses the API credentials (Key ID and password) from the right environment. Your live store needs production credentials. See Finding your API credentials in the Kustom Portal.
Check that the Key ID and password have been copied correctly into your platform, without extra spaces.
If the error continues, generate new API credentials in the Kustom Portal under Developers, then API, and enter them in your platform. See API.
Load your checkout again and check the API call logs to confirm the 401 error is gone.
Checkout blocked by your website's security settings
If your checkout does not load and your browser console shows errors about blocked content, your website's Content Security Policy may be blocking Kustom. See Content Security Policy.
When to contact Kustom support
If your checkout still does not load and you see other error messages in your API call logs, contact Kustom support. Include the following details so we can investigate quickly:
Your Merchant ID (MID). See How to find your Merchant ID.
What you were trying to do when the error happened.
The exact error messages from your API call logs.