Quickstart · Nowgate docs

Create a payment#

Use an SDK or plain HTTP. With an SDK, make a client with your API key:

const nowgate = new Nowgate({ apiKey: env("NOWGATE_API_KEY"), baseUrl, fetch: counted });

client = Nowgate(api_key=env("NOWGATE_API_KEY"), base_url=base_url, transport=counted)

$nowgate = new Client(['api_key' => env('NOWGATE_API_KEY'), 'base_url' => $baseUrl, 'transport' => $counted]);

Then send the network, the asset and the amount, with an idempotency key so a retry can never create a second payment. Your order ID makes a good key.

const payment = await nowgate.payments.create(
  { network: "tron", asset: "USDT", amount: "25.00", order_id: "1042" },
  { idempotencyKey: orderKey },
);

payment = client.payments.create(
    network="tron",
    asset="USDT",
    amount="25.00",
    order_id="1042",
    idempotency_key=order_key,
)

$payment = $nowgate->payments->create(
    ['network' => 'tron', 'asset' => 'USDT', 'amount' => '25.00', 'order_id' => '1042'],
    ['idempotency_key' => $orderKey],
);

curl https://api.nowgate.io/v1/payments \
  -H "Authorization: Bearer $NOWGATE_API_KEY" \
  -H "Idempotency-Key: order-1042" \
  -H "Content-Type: application/json" \
  -d '{"network": "tron", "asset": "USDT", "amount": "49.90", "order_id": "1042"}'

The response is the new payment, with status waiting:

{
  "id": "pay_01jc3x6k2tf8yq0b5n2c7m9d4v",
  "object": "payment",
  "status": "waiting",
  "network": "tron",
  "asset": "USDT",
  "amount": "49.9",
  "amount_received": "0",
  "amount_pending": "0",
  "amount_credited": "0",
  "fee": "0",
  "deposit": { "address": "TN3W4H6rK5ZsKxVbqh8ZpXhVv2dm3kGaQ1" },
  "late": false,
  "overpaid": false,
  "reversed": false,
  "order_id": "1042",
  "metadata": {},
  "expires_at": "2026-11-05T13:00:00Z",
  "created_at": "2026-11-05T12:00:00Z",
  "updated_at": "2026-11-05T12:00:00Z",
  "version": 1
}

Show the deposit address#

Show your customer deposit.address, the exact amount and asset, and the network, and when the payment expires (expires_at, an hour by default). On Stellar, also show deposit.memo: deposits without it can't be matched.

Or send them to the payment's checkout_url: a hosted page with all of that, a QR code their wallet can scan, and the payment's live status, in their language.

Receive the webhook#

As the payment changes, Nowgate POSTs events to your endpoint: payment.confirming when the deposit is seen, then payment.finished when it is final and credited. Verify each one over the raw body before trusting it. The SDKs verify it for you; without one, use a tested function from the webhooks guide:

const chunks: Buffer[] = [];
for await (const chunk of request) chunks.push(chunk as Buffer);
const body = Buffer.concat(chunks); // the raw body, exactly as received
const signature = request.headers["nowgate-signature"];
const event = await Webhooks.constructEvent(body, signature, secret);

body = self.rfile.read(int(self.headers["Content-Length"]))  # the raw body, exactly as received
signature = self.headers["Nowgate-Signature"]
try:
    event = Webhook.construct_event(body, signature, secret)
except SignatureVerificationError:
    self.send_response(400)
    self.end_headers()
    return

$payload = (string) file_get_contents('php://input'); // the raw body, exactly as received
$header = $_SERVER['HTTP_NOWGATE_SIGNATURE'] ?? null;
try {
    $event = Webhook::constructEvent($payload, is_string($header) ? $header : null, $secret);
} catch (SignatureVerificationException $e) {
    http_response_code(400);
    return;
}

Check before you deliver#

A webhook tells you something changed. Before you ship goods, fetch the payment and check its status. In the sandbox you can play the payer to see it happen:

const finished = await until("the payment to finish", async () => {
  const current = await nowgate.payments.retrieve(paid.id);
  assert.ok(!["expired", "failed"].includes(current.status), current.status);
  return current.status === "finished" ? current : undefined;
});

def finished() -> Optional[Payment]:
    current = client.payments.retrieve(paid["id"])
    check(current["status"] not in ("expired", "failed"), current["status"])
    return current if current["status"] == "finished" else None

payment = until("the payment to finish", finished)

$payment = until('the payment to finish', static function () use ($nowgate, $paid): ?array {
    $current = $nowgate->payments->retrieve($paid['id']);
    check(!in_array($current['status'], ['expired', 'failed'], true), $current['status']);
    return $current['status'] === 'finished' ? $current : null;
});

curl https://api.nowgate.io/v1/payments/pay_01jc3x6k2tf8yq0b5n2c7m9d4v \
  -H "Authorization: Bearer $NOWGATE_API_KEY"

Deliver when status is finished. A payment that received less than its amount is partially_paid instead: see underpayments.