Payments

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.

How it works

Initiate a payment

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

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.

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.

Validate the payment

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

Prerequisites

Authentication guide

Payment endpoints use Basic (Access ID) authentication — only your x-access-id header is required. See the authentication guide for details on both auth methods.

const BASE = 'https://sandbox-api.tender.cash/v1/api';
// makeHeaders() → { 'x-access-id': ACCESS_ID, 'Content-Type': 'application/json' }

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
    meta: { customerEmail: 'customer@example.com' }, // optional metadata
  }),
});

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;

res = requests.post(
    f"{BASE}/payment/initiate",
    headers=make_headers(),
    json={
        "amount":    "10.00",
        "chain":     "tron",
        "coin":      "usdt",
        "reference": "ORDER-9821",
        "meta":      {"customerEmail": "customer@example.com"},  # optional metadata
    },
)
payment = res.json()["data"]
tx_id         = payment["txId"]
wallet_address = payment["walletAddress"]

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.

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);

import time

def poll_payment(tx_id, interval_s=8):
    while True:
        res  = requests.post(f"{BASE}/payment/validate/{tx_id}", headers=make_headers())
        data = res.json()["data"]

        print(f"Status: {data['status']} | Received: {data['amountReceived']}")

        if data["status"] == "completed":
            return data
        if data["status"] == "failed":
            raise RuntimeError("Payment failed")

        time.sleep(interval_s)

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.

Payment status values

Status	Meaning
`pending`	Address generated; awaiting customer transfer
`partial`	Some funds received but not the full amount
`completed`	Full amount received and confirmed on-chain
`failed`	Payment expired or rejected

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

Error handling

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

Getting started

Online payments

Subwallets

Webhooks

How it works

Prerequisites

Authentication guide

Step 1 — Initiate a payment

Step 2 — Show payment details to your customer

Step 3 — Poll for payment status

Payment status values

Partial payments

Error handling

​How it works

​Prerequisites

Authentication guide

​Step 1 — Initiate a payment

​Step 2 — Show payment details to your customer

​Step 3 — Poll for payment status

​Payment status values

​Partial payments

​Error handling

How it works

Prerequisites

Step 1 — Initiate a payment

Step 2 — Show payment details to your customer

Step 3 — Poll for payment status

Payment status values

Partial payments

Error handling