Crypto On/Off Ramp API

API Endpoint

Live APIProduction environment

POSThttps://api.thepayment.company/api/v1/live/crypto

Test APISandbox environment

POSThttps://api.thepayment.company/api/v1/test/crypto

Overview

The Crypto On/Off Ramp API provides a single solution for both on-ramp and off-ramp cryptocurrency transactions:

On-ramp (fiat to crypto): Convert fiat currency into cryptocurrency
Off-ramp (crypto to fiat): Convert cryptocurrency into fiat currency

Both transaction types are handled through the same API endpoint, with the transaction type specified in the request payload.

Request Fields

Parameter	Type	Description	Required
`first_name`	String	User first name, 3-191 letters only	Yes
`last_name`	String	User last name, 3-191 letters only	Yes
`phone_number`	String	User phone number, 8-19 digits with an optional `+` prefix	Yes
`transaction_type`	String	Transaction type: `ONRAMP` (fiat to crypto) or `OFFRAMP` (crypto to fiat)	Yes
`fiat_currency`	String	Fiat currency code, 3 characters, for example USD or EUR	Yes
`crypto_currency`	String	Cryptocurrency code, for example BTC, ETH, or USDT	Yes
`crypto_network`	String	Cryptocurrency network, for example ETHEREUM or BITCOIN	Yes
`crypto_amount`	Number	Cryptocurrency amount, required for `OFFRAMP` and not allowed for `ONRAMP`	Conditional
`fiat_amount`	Number	Fiat amount, required for `ONRAMP` and not allowed for `OFFRAMP`	Conditional
`wallet_address`	String	Crypto wallet address used to receive or send funds	Yes
`ip_address`	String	User IP address	Yes
`email`	String	User email address	Yes
`country`	String	Country code in ISO 3166-1 alpha-2 format	Yes
`payment_method`	String	Payment method: `CARD`, `BANK`, or `WALLET`	No
`redirect_url`	String	URL where the user is redirected after the transaction	Yes
`webhook_url`	String	URL used for server-to-server webhook updates	No
`order_id`	String	Merchant-side unique order reference	No
`terminal_id`	String	Unique connector terminal ID, useful when choosing a primary or fallback connector	No

Transaction Type Rules

ONRAMP transactions:

fiat_amount is required
crypto_amount should not be sent
The user pays in fiat currency and receives cryptocurrency

OFFRAMP transactions:

crypto_amount is required
fiat_amount should not be sent
The user sends cryptocurrency and receives fiat currency

Sample Payloads

On-Ramp Transaction (Fiat to Crypto)

{
  "first_name": "John",
  "last_name": "Doe",
  "phone_number": "+1234567890",
  "transaction_type": "ONRAMP",
  "fiat_currency": "USD",
  "crypto_currency": "BTC",
  "crypto_network": "BITCOIN",
  "fiat_amount": 1000,
  "wallet_address": "bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh",
  "ip_address": "192.168.1.1",
  "email": "john.doe@example.com",
  "country": "US",
  "order_id": "ORD123456789",
  "redirect_url": "https://example.com/success",
  "webhook_url": "https://example.com/webhook"
}

Off-Ramp Transaction (Crypto to Fiat)

{
  "first_name": "Jane",
  "last_name": "Smith",
  "phone_number": "+1987654321",
  "transaction_type": "OFFRAMP",
  "fiat_currency": "EUR",
  "crypto_currency": "ETH",
  "crypto_network": "ETHEREUM",
  "crypto_amount": 2.5,
  "wallet_address": "0x32Be343B94f860124dC4fEe278FDCBD38C102D88",
  "ip_address": "192.168.1.2",
  "email": "jane.smith@example.com",
  "country": "DE",
  "order_id": "ORD123456789",
  "redirect_url": "https://example.com/success",
  "webhook_url": "https://example.com/webhook"
}

Sample Responses

{
"status": "REDIRECT",
"message": "Please redirect user to complete the payment.",
"redirect_url": "https://example.com/success",
"data": {
  "transaction_id": "TXN123456789",
  "fiat": "USD",
  "fiat_amount": 1000,
  "crypto": "BTC",
  "crypto_amount": 0.025,
  "customer": {
    "first_name": "John",
    "last_name": "Doe",
    "email": "john.doe@example.com"
  }
}
}

Encrypted payment APIs must use AES-256-CBC before transmitting sensitive fields. Authentication, headers, encryption steps, and sample implementations for Node.js, PHP, Python, and Java are documented in Integration Examples.