API overview - Ionic Docs

The customer-facing API reference is split into lightweight orientation pages and generated endpoint pages. Use orientation pages to understand the model and lifecycle. Use endpoint pages for exact methods, paths, authentication, headers, parameters, request payloads, response payloads, examples, and error shapes.

Start with these

Area	Overview	Endpoint examples
Checkout	Checkout sessions	Create checkout session, Confirm checkout session, Get checkout session
Payment links	Payment links	Create payment link, Update payment link
Catalog	Catalog	Create product, Create price
Customers	Customers	Create customer, Update customer
Payment intents	Payment intents	Create payment intent, Get payment intent
Refunds	Refunds	Create refund, Get refund
Terminal payments	In-person terminal payments	`POST /terminals/{id}/process_payment_intent`, `GET /terminal_payments/{id}`
Invoices	Invoices	`POST /invoices`, `GET /invoices/{id}`
Subscriptions	Subscriptions	`POST /subscriptions`, `GET /subscriptions/{id}`
Credit notes	Credit notes	`POST /credit_notes`, `GET /credit_notes/{id}`
Saved cards	Save a card for later	`POST /setup_intents`, `POST /setup_intents/{id}/confirm`
Webhooks	Webhooks	`POST /webhook_endpoints`, `GET /webhook_endpoints/{id}`

Shared behavior

Topic	Why it matters
Authentication	Server-side requests use secret keys. Hosted checkout URLs stay buyer-facing.
Request and response shape	Common resource shape, timestamps, nullability, and metadata.
IDs	Prefixes such as `cs_`, `pl_`, `prod_`, `price_`, `cus_`, and `rf_`.
Idempotency	Safe retries for create and refund requests.
Errors	Standard error envelope and payment decline details.
Pagination	List endpoint pagination patterns.
Rate limits	Headers and retry behavior.
Backwards compatibility	How the API evolves without breaking integrations.