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Tender generates a unique wallet address for each payment request. Your customer sends the exact crypto amount to that address, Tender detects the on-chain transfer, and marks the transaction complete. No custodial account or key management is required on your side.

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How it works

1

Initiate a payment

Call POST /payment/initiate with the amount, chain, and coin. Tender returns a walletAddress and a txId to track the transaction.
2

Customer sends crypto

Display the walletAddress and exact amount to your customer. They send from their own wallet — any compatible wallet on that chain works.
3

Tender detects the transfer

Tender monitors the address on-chain. When the payment arrives, the transaction status updates automatically. You can poll or listen via webhook.
4

Validate the payment

Call POST /payment/validate/{id} to confirm the payment is received and the transaction is complete on your end.

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Prerequisites

Authentication guide

All requests require an HMAC-SHA256 signature. See the authentication guide for code examples.
const BASE = 'https://sandbox-api.tender.cash/v1/api';
// makeHeaders() → { 'x-access-id', 'x-request-id', 'x-timestamp', 'authorization', ... }

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Step 1 — Initiate a payment

const res = await fetch(`${BASE}/payment/initiate`, {
  method: 'POST',
  headers: makeHeaders(),
  body: JSON.stringify({
    amount: '10.00',
    chain:  'tron',
    coin:   'usdt',
    reference: 'ORDER-9821', // your own order ID, optional
  }),
});

const { data: payment } = await res.json();
console.log(payment);
/*
{
  txId:          "66aec7de809b7f45c42a49f9",
  walletAddress: "TQn9Y2khDD9JHTfVE5oB2h8BKWWM4LxKLT",
  amount:        "10.00",
  coin:          "usdt",
  chain:         "tron",
  status:        "pending",
  expiresAt:     "2025-06-10T11:00:00.000Z"
}
*/

const { txId, walletAddress, amount } = payment;

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Step 2 — Show payment details to your customer

Display the wallet address and exact amount. The customer must send exactly the specified amount — partial sends are tracked as partial payments. 
Please send:

  10.00 USDT
  Network: Tron (TRC-20)
  To:      TQn9Y2khDD9JHTfVE5oB2h8BKWWM4LxKLT

  Do not send from an exchange. Use a self-custody wallet.
  Payment expires in 1 hour.
The walletAddress is unique to this transaction. Never reuse addresses across payments.

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Step 3 — Poll for payment status

async function pollPayment(txId, intervalMs = 8000) {
  while (true) {
    const res = await fetch(`${BASE}/payment/validate/${txId}`, {
      method: 'POST',
      headers: makeHeaders(),
    });
    const { data } = await res.json();

    console.log('Status:', data.status, '| Received:', data.amountReceived);

    if (data.status === 'completed') return data;
    if (data.status === 'failed')    throw new Error('Payment failed');

    await new Promise(r => setTimeout(r, intervalMs));
  }
}

const result = await pollPayment(txId);
Use webhooks instead of polling for production. Configure your webhook URL and Tender will push a notification the moment the payment status changes. See Webhooks.

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Payment status values

StatusMeaning
pendingAddress generated; awaiting customer transfer
partialSome funds received but not the full amount
completedFull amount received and confirmed on-chain
failedPayment expired or rejected

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Partial payments

If the customer sends less than the required amount, the transaction moves to partial status. The balanceRequired field shows what is still owed. You can:
  • Ask the customer to send the remaining balance to the same address
  • Mark the order as underpaid and handle it in your own logic

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Error handling

ScenarioAction
Customer sends wrong amountCheck amountReceived vs amount; handle partial if needed
Payment expiresInitiate a new payment; do not reuse the old address
Wrong networkFunds sent on the wrong chain cannot be recovered automatically — always display the network clearly
status: "failed"Initiate a fresh payment request