TypeScript

npm install nowgate

The SDK has no dependencies: it uses fetch and Web Crypto, so it runs on Node.js 22 and later, Deno, Bun and edge workers. Its types come from the API's spec. It runs on servers only: an API key must never reach a browser, so it refuses to start where a document exists.

Configure#

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

Every method takes a last options argument: { idempotencyKey, timeout, maxRetries, signal }.

Calls#

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

A call's promise resolves to the data. Its withResponse() resolves to the data with the status, the headers, the request's ID and the idempotency facts:

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

Errors#

try {
  await nowgate.payments.create({ network: "tron", asset: "USDT", amount: "25.0000001" });
} catch (err) {
  if (!(err instanceof InvalidRequestError)) throw err;
  // err.code is "amount_too_precise"; each field's problem has its JSON pointer
  pointer = err.errors[0]?.pointer;
  assert.equal(err.code, "amount_too_precise");
}

The errors are NowgateError, ApiError and its classes by status (AuthenticationError, PermissionError, NotFoundError, ConflictError, InvalidRequestError, RateLimitError, ServerError), ConnectionError when there's no answer, and SignatureVerificationError. A number where an amount goes is a TypeError, before anything is sent. See Errors.

Pages#

const all: string[] = [];
for await (const each of nowgate.payments.listAll()) all.push(each.id);

Amounts#

Amounts are strings. Amounts.toUnits, Amounts.fromUnits and Amounts.compare convert and compare them exactly, with bigint units. See Amounts.

Webhooks#

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);

Webhooks.verifySignature and Webhooks.constructEvent take the raw body as a string or bytes: in Express, express.raw({ type: "application/json" }); in a Next.js route, await request.text(). See Webhooks.

Your own HTTP client#

Pass a function with fetch's shape as fetch. When there's no answer, it rejects, as fetch does, and the client retries:

const counted = (url: string, init: RequestInit): Promise<Response> => {
  requests++;
  return fetch(url, init);
};