Square API
Payments, point of sale, catalog and customer management for in-person and online sellers.
Authentication
Access uses OAuth, so your users grant your app permission to act on their behalf. Request only the scopes you need, and store refresh tokens securely.
Pricing model
This is a paid API, usually billed per request or by usage. Some providers offer trial credits or test modes for development. Prices change often, so check the provider's pricing page before you commit, and model your bill at 10× today's volume.
Before you integrate
- Read the terms on caching, storing and displaying data.
- Note the rate limits and the error format so you can retry with backoff.
- Wrap calls behind your own interface so you can switch providers later.
- Pin an API version if the provider offers versioning, and watch its changelog.
Alternatives to Square API
Stripe API
Payments, subscriptions, invoicing and payouts with excellent developer tooling.
PayPal REST APIs
Checkout, payouts, subscriptions and invoicing through PayPal.
Lemon Squeezy API
Merchant-of-record checkout, subscriptions and license keys for digital products.
Paddle API
Merchant-of-record billing for SaaS, handling global tax and subscriptions.
Adyen API
Enterprise payment processing across online, mobile and in-store channels.