subbySubscription checkout is how a customer joins a plan on Subby. It enrols the customer, captures the required authorisation and connects the resulting mandate to the plan. You can embed checkout in your product with @mysubbyapp/checkout (subby.js), the WordPress plugin, or the Shopify app, or redirect the subscriber to a hosted Subby page.
Checkout is not a general payment form. It starts a subscription. The payment rail completes the charge; the subscription engine keeps the plan, mandate, schedule and subscription state connected.
Embedded checkout
The embedded element manages bank selection, authorisation instructions, waiting, success, error and expiry states. It auto-resizes inside the merchant page and communicates through an origin-checked, nonce-protected browser channel.
The merchant creates a checkout session on its server and passes only a short-lived client secret to the browser. Bank details stay within Subby's checkout surface. Embedding from an unapproved domain fails, and a pending mandate returns an expected activation time.
Use the quickstart for hosted checkout, or @mysubbyapp/checkout when you want the iframe on your own page. WordPress and Shopify teams can skip the SDK and follow the WordPress plugin or Shopify app guides.
Hosted checkout
Hosted checkout uses the same session and user interface as the embedded element. It adds merchant branding plus success and cancellation redirects, making it the shortest path for teams that do not want to embed a component.
How payment rails fit in
The payment experience changes with the available rail:
- Automatic debit: the subscriber authorises a mandate once. The subscription engine can then attempt scheduled renewals within the mandate rules.
- Subscriber-initiated collection: the subscriber completes each cycle after a reminder. The subscription still has a plan, schedule and recovery policy; the charge waits on subscriber action.
Read Country and rail coverage before designing a multi-country flow.
Frequently asked questions
How do I start a subscription?
Create a checkout session on your server, then embed Subby checkout or send the subscriber to hosted checkout. The session enrols the customer and attaches the mandate to the plan.
Is Subby checkout a payment gateway?
No. Checkout is the enrolment surface of the Subscription OS. Payment rails collect the charge. Subby stores the mandate, starts the subscription and emits lifecycle events.
Integration options
- @mysubbyapp/checkout — npm, CDN, React and Vue. Mount the iframe with a client secret.
- WordPress plugin — Shortcode, settings page, hooks and a REST webhook.
- Shopify app — Enable Subby on selected products and sync Shopify orders.