Payment Providers

Provider Architecture

FastAPI Payments is built around the concept of payment providers. Each provider implements a common interface defined in the PaymentProvider abstract base class, enabling you to switch providers with minimal code changes.

The Provider Interface

Each provider implements these key methods:

Customer Management

create_customer: Create a customer in the provider’s system
retrieve_customer: Get customer details from the provider
update_customer: Update customer details
delete_customer: Delete a customer

Payment Method Management

create_payment_method: Register a payment method for a customer
list_payment_methods: List a customer’s payment methods
delete_payment_method: Remove a payment method

Product and Plan Management

create_product: Create a product in the provider’s system
create_price: Create a pricing plan for a product

Subscription Management

create_subscription: Subscribe a customer to a plan
retrieve_subscription: Get subscription details
update_subscription: Update subscription details
cancel_subscription: Cancel a subscription

Payment Processing

process_payment: Process a one-time payment
refund_payment: Process a refund
record_usage: Record usage for usage-based billing

Webhook Handling

webhook_handler: Process webhook events from the provider

Supported Providers

Stripe Provider

The Stripe provider offers comprehensive payment processing capabilities:

Full support for Stripe API
Credit card processing
Subscription management
Usage-based billing
Webhook handling with signature verification

Example Stripe configuration:

{
  "providers": {
    "stripe": {
      "api_key": "sk_test_your_stripe_key",
      "webhook_secret": "whsec_your_webhook_secret",
      "sandbox_mode": true,
      "additional_settings": {
        "api_version": "2023-10-16"
      }
    }
  }
}

PayPal Provider

The PayPal provider supports:

PayPal checkout
Credit card processing via PayPal
Subscription billing
Webhook handling

Example PayPal configuration:

{
  "providers": {
    "paypal": {
      "api_key": "your_paypal_client_id",
      "api_secret": "your_paypal_secret",
      "sandbox_mode": true
    }
  }
}

Adyen Provider

The Adyen provider supports:

Global payment methods
Credit card processing
Tokenized payments
Webhook notification handling

Example Adyen configuration:

{
  "providers": {
    "adyen": {
      "api_key": "your_adyen_api_key",
      "webhook_secret": "your_adyen_webhook_secret",
      "sandbox_mode": true,
      "additional_settings": {
        "merchant_account": "YourMerchantAccount"
      }
    }
  }
}

Adding Custom Providers

You can create custom providers by implementing the PaymentProvider abstract base class. See ../advanced/extending for details.