Step 1: Create Your Account
Sign up for a free Cost+ account at dashboard.costplus.io/register. No credit card required. You will get instant access to the Merchant Portal where you can manage your websites, view transactions, and configure payment methods.
Step 2: Set Up a Website
In the Merchant Portal, navigate to Websites and create a new website. You can create a sandbox website for testing or a production website for live payments. Each website gets its own API key.
Step 3: Get Your API Key
Go to Websites, select your website, and click Integration. Here you will find your API key and Merchant ID. Keep your API key secure and never expose it in client-side code.
Step 4: Accept Your First Payment
The fastest way to start is using the Hosted Payment Page. Create an order via the API and redirect your customer to the payment URL. Here is what a basic order looks like:
- Send a POST request to https://api.costplus.online/v1/orders/
- Include currency (e.g., "EUR"), amount in cents (e.g., 1295 for EUR 12.95), and a return URL
- The API returns a payment_url - redirect your customer there
- After payment, the customer returns to your return_url
- Verify the payment status via the API or webhooks
Step 5: Test Your Integration
Use your sandbox website's API key to test. There is no separate sandbox URL - you use the same endpoint (https://api.costplus.online/v1/) with sandbox credentials. Use test card number 4111 1111 1111 1111 with any future expiry date and any 3-digit CVC.
Connect Your Store
If you use an eCommerce platform, install our official plugin instead of coding directly against the API. We support Shopify, WooCommerce, PrestaShop, Magento, OpenCart, Shopware, nopCommerce, Drupal Commerce, modified eCommerce, and osCommerce. Wix and Ecwid integrations are coming soon.
Need Help?
Contact our support team at support@costplus.io or visit our Help Desk at helpdesk.costplus.io. Our developer documentation is available at docs.costplus.io.