Overview
To continue using Kustom’s API, you must switch your integration from Klarna endpoints to Kustom endpoints before March 31, 2026.
To verify if you've switched API endpoints go to Kustom Portal (Integrations → API).
Most merchants only need to update the API endpoint.
Only generate new credentials if your integration gets authentication errors after switching endpoints.
Important dates
Deadline: March 31, 2026
If you don’t switch: your API connection will stop working, which may impact checkout and order operations
Downtime: none if you follow the steps below and deploy carefully
What stays the same
API endpoints, parameters, and request/response logic remain the same
Checkout, payouts, and settlement processes remain the same
Customer experience remains the same
What changes:
Your integration must call Kustom API endpoints instead of Klarna API endpoints.
Applicable services:
Kustom Checkout (API)
Kustom Order Management (API)
Kustom Settlement (API)
Kustom Hosted Payment Page (API)
Step-by-step: how to switch
Step-by-step: how to switch
Step 1: update the API endpoint (required)
Locate where your integration sets the API base URL or host.
Replace Klarna hostnames with Kustom hostnames:
From:
*.klarna.comTo:
*.kustom.co
Use the correct base URL for your environment:
Production:
api.kustom.coPlayground:
api.playground.kustom.co
Deploy the change.
Kustom cannot see where in your code or configuration you are calling Klarna. You must locate and update the API host in your integration yourself. This is normally done by a developer or IT team.
If you are unsure where it is configured, ask the person who maintains your integration to confirm that all API calls have been updated from *.klarna.com to *.kustom.co.
Note: the domain ends with .co, not .com.
Step 2: confirm the switch
Your switch is complete when your integration makes a successful request to the Kustom host.
To verify, check the API endpoint switch status page in the Kustom Portal (Integrations → API). It shows which services are still calling Klarna endpoints and the most recent time each host was used.
Note: The status is based on actual API requests. If your integration only calls the API once per day, the Portal will not update until the next request is made. If there is no traffic yet after your change, you may still see "Action required" until the first request hits the Kustom host.
Step 3: API credentials (only if needed)
Do not generate new API credentials unless you need to. Generate new Kustom API credentials only if you get authentication errors after switching host.
Generate new API credentials in the Kustom Portal
Update your integration configuration
Deploy and test again
Testing (recommended)
Testing (recommended)
Test in Playground first
Complete a test purchase to verify your checkout flow
If you do not have a test environment, switch during low-traffic hours and verify production checkout and order flows after deploy
If you have multiple stores or merchant IDs, repeat your changes for each one
Managing credentials
Managing credentials
How to generate new Kustom credentials
Production:
Go to Integrations in the left sidebar.
Select your store and click Generate new
Save credentials (since they are only visible once)
Playground (optional):
Use portal.playground.kustom.co and repeat the same steps to generate test credentials.
Storing credentials securely
Store API credentials securely and never share them publicly.
Rotating or revoking credentials
To rotate or revoke API credentials:
Log in to the Kustom Portal
Go to Integrations
Generate new credentials or delete old ones
Legacy Klarna credentials
You may need Klarna access for legacy/historical workflows. This does not change the requirement to switch your active integration host to Kustom before the deadline.
Whitelisted IP addresses
If you whitelist Kustom's IP addresses, they remain the same for both environments:
Production:
63.34.181.121
34.252.11.205
54.72.22.140
Playground:
54.75.162.237
99.80.156.64
99.80.3.148
If you use a platform integration
If you use a platform integration
If you use one of the platforms below, your platform handles the endpoint switch for you. This means you typically do not need to change the API host in your code yourself. Kustom will coordinate with your platform, and you will be notified when the update is ready.
Platforms that handle the switch for the merchant
Quickbutik AB
Abicart (Textalk Media, Digital Services)
Mystore.no AS
Sincos Software AS
24Nettbutik
MyCashflow
WGR Data AB
Vilkas Group Oy
Bokadirekt AB
Finqu Oy
Norce Commerce
Starweb AB
EG Retail Sweden
Nethit Systems Ltd Oy
Askås I & R AB
Centra Technology AB
eValent
Ny E-handel Sverige AB
TimeCenter AB
Litium Affärskommunikation AB
Visitgroup (Bookvisit)
Visma Webshop
E37 System AB
Kodmyran AB
Abicart AB
Viskan System AB
Salesforce Commerce Cloud (Demandware)
xt:Commerce GmbH
BrinkCommerce
Vendre (Optimizers Nordic AB)
Nordic Web Team
Pulse247 Oy
nopCommerce
ekmPowershop
r360 Resort Systems AB
Majako AB
Omnium AS
Kustom coordinates with your platform to handle endpoint updates. You will be notified when your platform’s integration is ready.
FAQ
FAQ
Do I need to generate new API credentials?
Not always. Start by switching the API endpoints to api.kustom.co. Only generate new credentials if you get authentication errors after switching.
Can I switch environments separately?
Yes. Switch Playground first (if you use it), then Production.
Will shoppers notice the switch?
No.
Can I keep old and new credentials active temporarily?
If you generate new credentials, keep the old ones until your new setup is verified. Do not wait until the deadline.
What happens if I miss the deadline?
API calls to Klarna endpoints will fail after March 31, 2026.