Off-Session Payment API

Create a OffSessionPayment request to initiate a payment with Jamm. This happens off-session, meaning a redirect link won't be returned, and the payment will be executed directly within your application. 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/OffSessionPayment→

▼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

Request Body

{}

Overview

The Off-Session 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)
• Execute a payment without redirecting anywhere
• Optionally send/collect metadata and other KYC information

Off-Session Payment POST

Endpoint

POST /api.v1.PaymentService/OffSessionPayment

Request Parameters

Customer Object

Parameter	Type	Required	Description
customer_id	string	Required	Customer ID

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

Response

Success Response

{
  "charge": {
    "id": "chg-73d45202-c751-40ac-8b8d-52eb8b009f53",
    "price": 100,
    "description": "商品の説明",
    "metadata": {
      "order_id": "order_456"
    }
}

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

Error Codes

INVALID_REQUEST

Missing or invalid parameters in the request

KYC_REQUIRED

Customer must complete KYC verification before proceeding

INVALID_AMOUNT

The charge amount is invalid or outside allowed range

Sequence Diagram