PAYMENTS FOR ONLINE STORES

API reference

Connect your store to crypto payments with four API methods.
Receive BTC, LTC, TRX and USDT TRC20, then transfer the funds when you need them.

API BASE${URL}/api/v1

Before you start

Ask your manager for these three details:

URL — your API address, starting with https://.
ACCOUNT_ID — your account ID.
Transfer Key — your secret key for transfers and callback settings.

Replace the placeholders below with your details. Use URL without a trailing slash. Keep the Transfer Key on your server.

How to specify amounts

The API uses whole numbers in the currency’s smallest unit:

1 BTC or LTC = 100,000,000 units
1 TRX or USDT = 1,000,000 units

For example, send 100000 for 0.001 BTC, or 1000000 for 1 USDT.

A typical payment: set your callback → create an address for the order → verify the incoming transaction. Transfer funds whenever you need to.

The examples update automatically

The examples are templates. Replace the placeholders with your details; the page itself never sends a payment.

New address

No Transfer Key

POST/accounts/{account}/addresses

Create an address and show it to your customer at checkout. Save it with the order so you can match the incoming payment to the right purchase.

JSON body
Field	Description
`currency`required	`btc`, `ltc`, `trx` or `usdt@trx`.
`callback`optional	Override the account callback for this address. Put your order reference in `data`.
`addr-type`optional	BTC: `p2sh-p2wpkh` (default) or `p2wpkh`. LTC: `p2wpkh`. TRX/USDT: `generic`.

Each successful request creates a new address, including identical requests. Do not automatically repeat a request after a lost response.

TRX and USDT share the account’s TRON address list. Always specify the intended currency.

Request cURL

curl --request POST "${URL}/api/v1/accounts/${ACCOUNT_ID}/addresses" \
  --header 'Content-Type: application/json' \
  --data-raw '{
  "currency": "btc",
  "callback": {
    "url": "https://merchant.example/payments/callback",
    "method": "POST",
    "data": {
      "order_id": "ORDER_1001"
    }
  }
}'

200 response JSON

{
  "account": "00000000000000000000000000000001",
  "currency": "btc",
  "address": "YOUR_RECEIVING_ADDRESS",
  "created": "2026-09-05T12:00:00.000000",
  "type": "p2sh-p2wpkh",
  "callback": {
    "url": "https://merchant.example/payments/callback",
    "method": "POST",
    "data": {
      "order_id": "ORDER_1001"
    }
  }
}

Transfer

Transfer Key required

POST/accounts/{account}/transfer

Send funds to a destination address. The example sends 100% of the available balance in the selected currency, after network and service fees.

JSON body
Field	Description
`currency`required	The currency to send.
`transfer-key`required	Your private 32-character Transfer Key.
`destinations`required	Recipient `address` and `amount`. Use `"100%"` for a sweep, or an integer for a fixed amount.
`fee`optional	Use `normal`.
`addresses`optional	Array of your source addresses. Omit to select automatically; fixed-amount TRON transfers can use a single covering address.
`fee-limit` `processing-fee-limit`optional	Maximum network and service fees in atomic units of the selected currency. Omitted limits use the current quote.

Save the returned payment id. success means publication; check TXID info for confirmation. TRX/USDT can return pending before any TXID exists.

Fees and uncertain responses

A single 100% destination deducts both fees automatically. For fixed amounts, fees are added unless subtract-fee-from-amount is true. USDT network and service fees are paid in USDT; the platform supplies execution TRX.

Do not retry the POST automatically: you could send funds again. After a timeout, lost response, 500 or 503, check the saved payment before sending again. A missing ID or a 404 alone does not prove rejection. If the outcome is still unknown, contact your manager before making another transfer.

TRON may finish with a partial-transfer error: some funds were sent. Inspect the saved payment; do not repeat the POST.

Request cURL

curl --request POST "${URL}/api/v1/accounts/${ACCOUNT_ID}/transfer" \
  --header 'Content-Type: application/json' \
  --data-raw '{
  "currency": "btc",
  "transfer-key": "YOUR_TRANSFER_KEY",
  "destinations": [
    {
      "address": "YOUR_DESTINATION_ADDRESS",
      "amount": "100%"
    }
  ],
  "fee": "normal"
}'

200 response · selected fields JSON

{"account":"00000000000000000000000000000001","currency":"btc","type":"payment","id":"8312c94cb8d4a9025f7d1c783f2be9a446c0e837965219b46792ac8523d9f068","status":"success","txs":["aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"]}

TXID info

No Transfer Key

GET/accounts/{account}/history/{id}

Verify a payment associated with your account. For an incoming payment, use its blockchain TXID. For a transfer you submitted, use the returned payment ID, including while it has no TXID yet.

Path and query parameters
Field	Description
`id`path	Incoming TXID or saved payment ID; 64 lowercase hexadecimal characters.
`currency`query	Always include it in your integration, especially `usdt@trx` for USDT TRC20.

For incoming funds, match items[].address and sum the corresponding items[].amount for your order. Check the account, currency, is_confirmed and observation freshness before fulfilling it. The top-level amount may include several receiving addresses.

A payment ID and a blockchain TXID are different identifiers. This method looks up your account’s recorded activity; it is not a general blockchain explorer.

503 means confirmation cannot currently be verified. Retry the read after Retry-After; do not treat it as an unpaid order. 404 means the item is not available for this account.

Request cURL

curl --get "${URL}/api/v1/accounts/${ACCOUNT_ID}/history/${TXID_OR_PAYMENT_ID}" \
  --data-urlencode 'currency=btc'

200 response · incoming payment JSON

{
  "account": "00000000000000000000000000000001",
  "currency": "btc",
  "created": "2026-09-16T12:00:00.000000",
  "type": "receipt",
  "id": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
  "items": [
    {
      "txid": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
      "created": "2026-09-16T12:00:00.000000",
      "vout": 0,
      "event_kind": "utxo_output",
      "address": "YOUR_RECEIVING_ADDRESS",
      "amount": 100000,
      "block": {
        "hash": "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
        "height": 101,
        "deleted": false
      },
      "is_confirmed": true
    }
  ],
  "amount": 100000,
  "is_confirmed": true,
  "observation_status": "recorded",
  "as_of": {
    "height": 120,
    "block_hash": "cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc",
    "checked_at": "2026-09-16T12:00:01.000000",
    "source_height": 120,
    "lag_blocks": 0
  }
}

Set callback

Transfer Key required

PATCH/accounts/{account}

Tell the service where to notify your store about incoming payments. This callback becomes the default for new addresses unless you set a separate one for an order.

JSON body
Field	Description
`currency`required	The currency to configure. TRX and USDT share callback defaults; BTC and LTC are separate.
`transfer-key`required	Your private Transfer Key.
`callback.url`required	Your public HTTPS endpoint. Redirects and private-network destinations are not followed.
`callback.method`optional	`POST` (default, JSON body) or `GET` (query parameters).
`callback.data`optional	Your metadata, returned with each notification.

Setting callback to {} disables notifications. An address callback of null inherits the account default. Changes apply to newly created events; queued events retain their saved settings.

Receive, verify, acknowledge

Save the event durably. Deduplicate retries by X-Coinkun-Event-ID; credit each transaction position once.
Verify the incoming TXID with method 03 and compare the currency, receiving address and amount with your order. Callback headers are not cryptographic signatures.
Reply 200, Content-Type: text/plain, with the exact body *ok*.

Acknowledging a pending event stops the later confirmed notification. If you acknowledge early, keep polling method 03. To wait for confirmation via callback, do not return *ok* for pending. Corrections such as dropped can still arrive.

Unacknowledged receipts retry after each processed BTC/LTC block, or every five TRON blocks, within their delivery window. Delivery can repeat and arrive out of order.

Request cURL

curl --request PATCH "${URL}/api/v1/accounts/${ACCOUNT_ID}" \
  --header 'Content-Type: application/json' \
  --data-raw '{
  "currency": "btc",
  "transfer-key": "YOUR_TRANSFER_KEY",
  "callback": {
    "url": "https://merchant.example/payments/callback",
    "method": "POST",
    "data": {}
  }
}'

200 response · selected fields JSON

{"account":"00000000000000000000000000000001","currency":"btc","callback":{"url":"https://merchant.example/payments/callback","method":"POST","data":{}}}

Incoming notification JSON

{"account":"00000000000000000000000000000001","currency":"btc","value":100000,"input_address":"YOUR_RECEIVING_ADDRESS","confirmations":1,"input_transaction_hash":"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa","network":"mainnet","event":"confirmed","status":"confirmed","event_kind":"utxo_output","position":0,"data":{"order_id":"ORDER_1001"}}