American Express for Medusa
American Express is a globally established premium card brand. Combined with Medusa, the open-source commerce framework for headless shops, you offer your customers exactly the payment option they expect at checkout. With zahls.ch you connect the two without any coding: create an account, set up the integration, activate American Express. It then appears directly in the checkout of your Medusa store, and all transactions are gathered clearly in your dashboard.
Medusa is an open-source commerce framework for headless shops: products, cart, checkout, and admin run as a Node.js backend that connects storefronts and custom apps via APIs.
The connection to zahls.ch uses the official npm package @zahls/medusa-plugin. You install it in the Medusa backend, register the payment provider in medusa-config.ts, and enter your API key plus instance name.
Customers pay via the hosted zahls.ch checkout (redirect). Captures, refunds, and status updates run through Medusa payment webhooks – optionally with HMAC signature verification.
Medusa suits teams running a developer-driven headless store that need Swiss payment methods such as TWINT, cards, and PostFinance.
Features
- Official npm plugin for Medusa v2
- Hosted checkout with redirect
- Captures and refunds via the API
- Webhooks with optional HMAC verification
- TWINT, cards and PostFinance at checkout
Benefits
- Reach Amex customers with higher basket values
- Fast activation without coding skills
- Stable API connection with automatic status updates
- Official Medusa v2 integration with webhooks
Use cases
American Express for Medusa pays off in many scenarios:
- Business and premium customers with American Express cards
- Stores that want to reduce checkout abandonment with familiar payment methods
- Merchants who want to manage transactions, refunds, and payouts in one place
Setup
How to set up American Express in Medusa
- Create a zahls.ch account and complete verification.
- Install the @zahls/medusa-plugin npm package, register the payment provider in medusa-config.ts, and enter your API key plus instance name.
- Enter the API keys from your zahls.ch dashboard in the integration settings.
- Activate American Express as a payment method and save the configuration.
- Run a test payment in test mode, then switch your store live.
FAQ
Do I need a separate contract for American Express?
No. You activate American Express in your zahls.ch account – without a separate acquiring contract.
How long does the setup in Medusa take?
Usually less than an hour: install the integration, enter the API keys, activate the payment method, and test.
What does using American Express cost?
Transaction fees depend on your chosen zahls.ch plan. There are no setup fees for the integration itself.