Transfer

Send cryptocurrency from a customer's HD wallet to any on-chain address.

Endpoint

POST /api/v1/wallet/:customerID/transfer

Authentication

Requires API key in the X-API-Key header. Also requires the wallet:transfer permission on the key.

Path Parameters

Parameter	Type	Description
customerID	string	Your internal customer identifier

Request Body

Field	Type	Required	Description
network	string	Yes	Blockchain network code
currency	string	Yes	Token to send
to_address	string	Yes	Recipient blockchain address
amount	string	Yes	Amount in base units (see table below)
index	integer	No	Derivation index to send from (default: 0)

Amount Units

Always pass amounts as integer strings in the network's smallest unit. Never pass decimals.

Network	Currency	Unit	Decimals	1 human unit =
BTC	BTC	satoshi	8	100000000
LTC	LTC	satoshi	8	100000000
BCH	BCH	satoshi	8	100000000
ETH	ETH	wei	18	1000000000000000000
BSC	BNB	wei	18	1000000000000000000
POL	MATIC/POL	wei	18	1000000000000000000
ETH	USDT	micro-USDT	6	1000000
ETH	USDC	micro-USDC	6	1000000
BSC	USDT	wei-USDT	18	1000000000000000000
BSC	USDC	wei-USDC	18	1000000000000000000
POL	USDT	wei-USDT	18	1000000000000000000
POL	USDC	wei-USDC	18	1000000000000000000
TRX	TRX	sun	6	1000000
TRX	USDT	sun-USDT	6	1000000
SOL	SOL	lamport	9	1000000000
SOL	USDC	micro-USDC	6	1000000
XRP	XRP	drop	6	1000000

BSC/POL USDT and USDC are 18 decimals, not 6. This is correct for BEP-20/ERC-20 on these networks.

Blocked Combinations

The following combinations are rejected with 400 Bad Request:

Network	Currency	Reason
SOL	USDT	USDT does not exist as a native SPL token on Solana
TRX	USDC	USDC does not exist as a TRC-20 token on Tron

Use USDT on ETH, BSC, POL, or TRX. Use USDC on ETH, BSC, POL, or SOL.

Example Requests

Send BTC

// Send 0.01 BTC (= 1,000,000 satoshis)
const response = await fetch(
  'https://payments-api-dev-966260606560.europe-west2.run.app/api/v1/wallet/user_12345/transfer',
  {
    method: 'POST',
    headers: {
      'X-API-Key': 'live_sk_your_key_here',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      network: 'BTC',
      currency: 'BTC',
      to_address: 'bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh',
      amount: '1000000',
      index: 0
    })
  }
);

const transfer = await response.json();
console.log('Transaction Hash:', transfer.tx_hash);
console.log('Status:', transfer.status);

Send USDT on ETH

// Send 50 USDT on Ethereum (6 decimals → 50,000,000)
const response = await fetch(
  'https://payments-api-dev-966260606560.europe-west2.run.app/api/v1/wallet/user_12345/transfer',
  {
    method: 'POST',
    headers: { 'X-API-Key': 'live_sk_your_key_here', 'Content-Type': 'application/json' },
    body: JSON.stringify({
      network: 'ETH',
      currency: 'USDT',
      to_address: '0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb',
      amount: '50000000',   // 50 USDT — ETH USDT is 6 decimals
      index: 0
    })
  }
);
const transfer = await response.json();
console.log('tx_hash:', transfer.tx_hash);

Send USDT on BSC

// Send 50 USDT on BSC (18 decimals → 50 × 10^18)
const response = await fetch(
  'https://payments-api-dev-966260606560.europe-west2.run.app/api/v1/wallet/user_12345/transfer',
  {
    method: 'POST',
    headers: { 'X-API-Key': 'live_sk_your_key_here', 'Content-Type': 'application/json' },
    body: JSON.stringify({
      network: 'BSC',
      currency: 'USDT',
      to_address: '0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb',
      amount: '50000000000000000000',   // 50 USDT — BSC USDT is 18 decimals
      index: 0
    })
  }
);

Python

import requests

# Send 100 USDT on Tron (6 decimals)
response = requests.post(
    'https://payments-api-dev-966260606560.europe-west2.run.app/api/v1/wallet/user_12345/transfer',
    headers={
        'X-API-Key': 'live_sk_your_key_here',
        'Content-Type': 'application/json'
    },
    json={
        'network': 'TRX',
        'currency': 'USDT',
        'to_address': 'TYourRecipientAddress',
        'amount': '100000000',   # 100 USDT on TRX (6 decimals)
        'index': 0
    }
)

transfer = response.json()
print(f"Transaction: {transfer['tx_hash']}")
print(f"Gas Fee: {transfer['gas_fee']}")

cURL

curl -X POST https://payments-api-dev-966260606560.europe-west2.run.app/api/v1/wallet/user_12345/transfer \
  -H "X-API-Key: live_sk_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "network": "SOL",
    "currency": "USDC",
    "to_address": "YourRecipientSolanaAddress",
    "amount": "50000000",
    "index": 0
  }'

Response

Success (200 OK)

Field	Type	Description
tx_hash	string	Main transaction hash
from_address	string	Sender address (customer's derived wallet)
to_address	string	Recipient address
amount	string	Amount delivered to recipient in base units (gross minus any fee)
currency	string	Token sent
network	string	Blockchain network
gas_fee	string	Network gas fee in base units (native token)
status	string	pending — transaction is broadcast, awaiting confirmation
timestamp	string	ISO 8601 timestamp
fee_amount	string	(optional) Fee collected in base units — omitted if no fee configured
fee_tx_hash	string	(optional) Fee transaction hash. Empty for BTC/LTC/BCH (fee is part of main tx). Omitted if no fee.

{
  "tx_hash": "0x1a2b3c4d5e6f...",
  "from_address": "0x8B3192f2f0f0D7E4F5C3A1B9E2D7A6C5B4D3E2F1",
  "to_address": "0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb",
  "amount": "49500000",
  "currency": "USDT",
  "network": "ETH",
  "gas_fee": "2100000000000000",
  "status": "pending",
  "timestamp": "2026-06-26T12:00:00Z",
  "fee_amount": "500000",
  "fee_tx_hash": "0xdeadbeef..."
}

The amount in the response is what the recipient receives — gross minus fee. If no fee is configured, amount equals the amount from the request.

Error Responses

400 — Blocked combination

{ "error": "USDT is not supported on Solana — use USDT on ETH, BSC, POL, or TRX" }

{ "error": "USDC is not supported on Tron — use USDC on ETH, BSC, POL, or SOL" }

500 — Broadcast failed

{ "error": "transfer failed: insufficient funds: need 150000 satoshis, have 80000 (fee 12000)" }

Transaction Status

The response always returns status: "pending". Track confirmation via webhooks:

Status	Webhook	Meaning
pending	—	Transaction broadcast, awaiting block inclusion
confirmed	wallet.transfer.confirmed	Transaction included in block
failed	wallet.transfer.failed	Transaction rejected

WaaS Fee Collection

If your business has configured a WaaS fee (see POST /api/v1/settings/waas/fees), the fee is automatically applied to every transfer on networks where you have a receiving address set:

• Gross amount is what the customer initiates (the amount field you send)
• Net amount goes to the recipient (amount in the response)
• Fee goes directly on-chain to your configured fee address (not through any platform intermediary)

Fee mechanics per chain type:

Chain	How fee is collected
BTC, LTC, BCH	Single transaction with 3 outputs: recipient + your fee address + change
SOL (native)	Single transaction with 2 transfer instructions
ETH, BSC, POL, TRX, XRP, SOL USDC	Two sequential transactions — main transfer first, then fee

Block Explorers

Network	Explorer	URL Format
Bitcoin	Mempool.space	https://mempool.space/tx/{tx_hash}
Litecoin	Blockchair	https://blockchair.com/litecoin/transaction/{tx_hash}
Bitcoin Cash	Blockchair	https://blockchair.com/bitcoin-cash/transaction/{tx_hash}
Ethereum	Etherscan	https://etherscan.io/tx/{tx_hash}
BSC	BscScan	https://bscscan.com/tx/{tx_hash}
Polygon	PolygonScan	https://polygonscan.com/tx/{tx_hash}
Tron	Tronscan	https://tronscan.org/#/transaction/{tx_hash}
Solana	Solscan	https://solscan.io/tx/{tx_hash}
XRP	XRPScan	https://xrpscan.com/tx/{tx_hash}

Related Endpoints

• Estimate Gas — Estimate network fees before transfer (EVM only)
• Get Transactions — View transfer history
• List Addresses — Check on-chain balances
• WaaS Fee Config — Configure your fee collection