On-Session Payment API

Create a OnSessionPayment request to initiate a payment with Jamm. This happens on-session, meaning a redirect link will be returned, to redirect the user to Jamm for executing the payment. You can call this API to charge an existing customer (by including a customer ID in the request), or create one by omitting it.

POST/api.v1.PaymentService/OnSessionPayment→

▼buyer

email*Customer's email address

force_kyc*Whether to require KYC verification

nameCustomer's full name

▼charge

price*Amount to charge in JPY

description*Description of the charge

▼redirect

success_url*URL to redirect after successful payment

failure_url*URL to redirect after failed payment

Request Body

{}

Overview

The Online Payment API allows you to:

• Create a charge for a new customer (if no Customer ID is provided)
• Create a charge for an existing customer (if a Customer ID is provided)
• Generate a payment link for the customer
• Optionally send/collect metadata and other KYC information

On-Session Payment POST

Endpoint

POST /api.v1.PaymentService/OnSessionPayment

Request Parameters

Customer Object

Parameter	Type	Required	Description
email	string	Required	Customer's email address
customer_id	string	Optional	Customer ID
force_kyc	boolean	Optional	Whether to require KYC verification
name	string	Optional	Customer's full name
katakana_last_name	string	Optional	Customer's last name in katakana
katakana_first_name	string	Optional	Customer's first name in katakana
address	string	Optional	Customer's address
birth_date	string	Optional	Customer's birth date (YYYY-MM-DD)
gender	string	Optional	Customer's gender ("male" or "female")
metadata	object	Optional	Additional data for tracking

Charge Object

Parameter	Type	Required	Description
price	number	Optional	Amount to charge in JPY
description	string	Optional	Description of the charge
metadata	object	Optional	Additional data for the charge
one_off_charge	boolean	Optional	Will not provide a customer id in response. Use if this charge is one-off (like a single EC payment) and you do not require saving customer id for future deductions.

Redirect Object

Parameter	Type	Required	Description
success_url	string	Required	URL to redirect after successful payment
failure_url	string	Required	URL to redirect after failed payment

Response

Success Response

{
  "charge": {
    "id": "chg-73d45202-c751-40ac-8b8d-52eb8b009f53",
    "price": 100,
    "description": "商品の説明",
    "metadata": {
      "order_id": "order_456"
    },
  "customer": {
    "id": "cus-ct7c7p31ihult8kvli20",
    "email": "example@email.jp",
    "createdAt": "2024-12-03T08:40:04.924031Z",
    "updatedAt": "2024-12-03T08:40:04.924031Z"
  },
    "expiresAt": "2024-12-03T10:10:04.923338257Z"
  },
  "paymentLink": {
    "url": "https://pay.jamm-pay.jp/payment?payment_id=09e09114-f0ac-4c2a-a669-8ad1c07b7209",
    "expiresAt": "2024-12-03T10:10:04.923338257Z"
  }
}

Response Fields

Field	Type	Description
charge.id	string	Always Unique identifier for the charge
charge.price	number	Always Amount to be charged in JPY
charge.metadata	object	Optional Additional data for the charge
customer.id	string	Optional Unique identifier for the customer
customer.email	string	Always Customer's email address
paymentLink.url	string	Always URL that can be sent to the customer
paymentLink.expiresAt	string	Always When the payment link expires

Error Codes

INVALID_REQUEST

Missing or invalid parameters in the request

PAYMENT_EXPIRED

The payment link has expired (90 minutes after creation)

KYC_REQUIRED

Customer must complete KYC verification before proceeding

CUSTOMER_EXISTS

A customer with this email already exists

INVALID_AMOUNT

The charge amount is invalid or outside allowed range

Sequence Diagram