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The Suward crypto payments API: REST endpoints, SDKs for TypeScript and Go, a hosted checkout, and signed webhooks. Everything below is described in full at suward.com/docs — no account required to read any of it.

Read the docs Mint test tokens

SDKsTypeScriptGoRESTAny other language

create-payment.ts

import { SuwardSDKClient } from "@crylabsorg/suward-sdk";

const suward = new SuwardSDKClient({
  apiKey: process.env.SUWARD_API_KEY,
});

const payment = await suward.payments.createPayment({
  amount: "1000000000", // integer string, smallest unit
  asset: "USDT_ARBITRUM",
  externalId: "order_4821", // makes the call idempotent
});

// every fee quoted before your customer confirms
console.log(payment.networkFee);
console.log(payment.paymentPageUrl); // hosted page, no frontend

Quickstart

Your integration, end to end

Create a payment with one API call — or skip the API and drop in the hosted checkout page.

checkout.ts

const payment = await suward.payments.createPayment({
  amount: "49000000", // smallest units — 49 USDC
  asset: "USDC_BASE",
  externalId: "order_9137",
});

res.redirect(payment.paymentPageUrl); // hosted checkout — no frontend work

Get notified by signed webhooks as the payment moves through its stages. Every notification is cryptographically signed: your server can reject anything that isn’t from Suward.

verify-webhook.ts

import { webhooks } from "@crylabsorg/suward-sdk";

const body = req.body.toString("utf8");

const isValid = await webhooks.WebhooksHelper.verifySignature(
  body,
  req.header("X-Suward-Signature"), // "ed25519=<hex>"
  SUWARD_WEBHOOK_PUBLIC_KEY,
  req.header("X-Suward-Timestamp"),
);
// rejects anything not signed by Suward

Act on Accepted, withdraw on Success. The two-stage settlement model is explicit in the API, so “can I ship?” and “can I withdraw?” are separate, answerable questions.

settlement.ts

switch (event.type) {
  case "payment.accepted":
    fulfillOrder(event.payment.externalId); // safe to ship
    break;
  case "payment.success":
    // irreversible — safe to withdraw
    break;
}

Reliability

Designed for the 3 a.m. failure cases

Retries are safe.

A retried request never creates a second payment — timeouts and crashes don’t turn into double charges.

Notifications can’t be forged.

Webhooks are signed; a spoofed “payment received” can’t trick your fulfillment.

Keys are containable.

API keys carry limits, support rotation, and can be revoked instantly — a leaked key is an event, not a catastrophe.

Upgrades don’t break you.

API changes are backward compatible — the integration you ship today keeps working as the product grows.

Test on real networks.

Suward test tokens are deployed on real networks: your integration is verified against production infrastructure, not a lookalike sandbox.

Testing

Test the whole flow before you take real payments

Anyone can mint Suward test tokens — no registration needed. The tokens are free and valueless; a mint is one on-chain transaction, so your wallet needs a small amount of the network’s native token for gas. Point your integration at real networks, pay with test tokens, and watch the full lifecycle, including test withdrawals on low-fee networks. Prefer to see it working before you build? Our demo store runs the same hosted checkout on test tokens — and its source code is public, so you can read a working integration end to end. To run the complete scenario (creating payments, receiving webhooks, using the dashboard), create a free account: it’s free unconditionally, and you can start accepting real payments right after sign-up — screening runs on every incoming payment, not as an onboarding gate. There is no separate sandbox that behaves differently from production: the same networks, the same API, the same webhooks and dashboard — the only difference is that the tokens are test assets.

Mint test tokens Create account

Everything else is in the docs

API reference, webhook signatures, settlement stages, asset and network coverage, error handling — documented in full, publicly, at suward.com/docs. And the API is stable by policy: changes are backward compatible and don’t break existing integrations.

Read the docs

The docs are public.Start there.