Initiating a Subscription

Method 1: Checkout Flow (Recommended)

The simplest way to initiate a subscription. Create a checkout session and redirect the customer.

From the Dashboard

Go to Subscriptions > select an offer.
Click Initiate Subscription.
The customer is sent to the hosted checkout page.

Via the API

curl -X POST https://api.inflowpay.xyz/subscription/offer/{offerId}/initiate \
  -H "X-Inflow-Api-Key: your_private_key" \
  -H "Content-Type: application/json" \
  -d '{
    "customerEmail": "[email protected]",
    "successUrl": "https://yoursite.com/welcome",
    "cancelUrl": "https://yoursite.com/pricing",
    "metadatas": {
      "userId": "usr_123",
      "plan": "pro"
    }
  }'

Request Body

Field	Type	Required	Description
`customerEmail`	string	No	Pre-fill the customer's email
`successUrl`	string	No	Redirect after successful payment
`cancelUrl`	string	No	Redirect if customer cancels
`metadatas`	object	No	Custom key-value data
`guestId`	string	No	Guest identifier
`paymentMethodRef`	string	No	Payment method reference (for waitlist-enabled offers)

Response

{
  "subscriptionId": "sub_abc123",
  "paymentId": "pay_abc123",
  "purchaseUrl": "https://checkout.inflowpay.com/..."
}

Redirect the customer to the purchaseUrl to complete the checkout.

Method 2: Server-to-Server

For direct card processing without redirecting the customer. Requires PCI-compliant infrastructure.

Important: Server-to-server integration requires sending card details to https://api-card.inflowpay.com, not the standard API URL.

curl -X POST https://api-card.inflowpay.com/subscription/offer/{offerId}/initiate-server \
  -H "X-Inflow-Api-Key: your_private_key" \
  -H "Content-Type: application/json" \
  -d '{
    "customerEmail": "[email protected]",
    "billingCountry": "FR",
    "purchasingAsBusiness": false,
    "firstName": "John",
    "lastName": "Doe",
    "card": {
      "number": "4242424242424242",
      "expMonth": 12,
      "expYear": 2027,
      "cvc": "123"
    },
    "autoConfirm": true,
    "metadatas": {
      "userId": "usr_123"
    }
  }'

Request Body

All fields from the checkout flow plus:

Field	Type	Required	Description
`customerEmail`	string	Yes	Customer email
`billingCountry`	string	Yes	ISO 3166-1 alpha-2 country code
`purchasingAsBusiness`	boolean	Yes	Business purchase flag
`businessName`	string	If business	Business name
`taxId`	string	If business	Business tax ID
`postalCode`	string	If US	Billing postal code
`firstName`	string	No	Customer first name (recommended for 3DS)
`lastName`	string	No	Customer last name (recommended for 3DS)
`savePaymentMethod`	boolean	No	Save the card for future charges (default: false). For subscriptions, the card is typically saved automatically for renewals. Use this when you want to explicitly control saving.
`useCustomerPaymentMethod`	boolean	No	Use the customer's last saved payment method (default: false). Use when the customer already has a card on file.
`card`	object	No	Card details (number, expMonth, expYear, cvc)
`autoConfirm`	boolean	No	Process immediately if no 3DS required
`pricingMode`	string	No	`TAX_EXCLUSIVE` or `TAX_INCLUSIVE`
`metadatas`	object	No	Custom metadata

Response

{
  "payment": {
    "id": "pay_abc123",
    "status": "INITIATION",
    "amountInCents": 2999,
    "currency": "EUR"
  },
  "threeDsSessionUrl": null
}

If threeDsSessionUrl is not null, redirect the customer to complete 3D Secure authentication.

Saving and reusing payment methods for subscriptions

savePaymentMethod: true — Saves the card for future subscription charges. For most subscriptions, the card is saved automatically for renewals.
useCustomerPaymentMethod: true — Uses the customer's last saved card. Use when the customer already has a card on file (e.g. from a previous subscription or payment). The customer must be identified by the same customerEmail.

You cannot use both in the same request. If the customer has no saved card yet, useCustomerPaymentMethod: true will fail.

After Initiation

Waitlist enabled: The subscription enters pending_waitlist status. You must approve it from the Dashboard.
Trial period: The subscription becomes ACTIVE immediately, but the first charge happens after the trial ends.
Entry fee: The first payment uses the entry fee amount; subsequent payments use the regular amount.
Standard: The customer is charged immediately and the subscription becomes ACTIVE.