Crypto payments that never touch our wallet.
Zynost Pay generates payment addresses from your own key. Customers pay you directly — there's no custody, no payout schedule, and nothing to withdraw.
Three steps, no intermediary.
Create a checkout
Your backend calls POST /v1/checkout with an amount. We return a unique receive address derived from your own xpub.
Customer pays
They send USDT/USDC to that address — directly to a wallet only you control. We never touch it.
You get notified
We watch the chain and fire a signed webhook the moment payment confirms, or your page polls the same status.
Custodial gateways vs. Zynost Pay
Typical custodial gateway
Zynost Pay
Create a checkout
curl -X POST https://zynostpay.umarae.com/api/v1/checkout \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"amount_usd": 9.99,
"order_reference": "order_123",
"description": "Pro plan"
}'The response includes a checkout_url you can redirect your customer to, or the raw address/amount to build your own UI. Poll GET /v1/checkout/{id} for status, or configure a signed webhook from your dashboard.
Built so we can't touch your money.
Watch-only key derivation
Your xpub lets us mint addresses under your wallet, never spend from it — the same math hardware wallets use for read-only address books.
HMAC-signed webhooks
Every webhook is signed with a secret only you and we know, so you can reject forged or replayed requests.
Direct chain reads
We confirm payment by reading the blockchain itself — no third-party indexer that could go down or lie about your balance.
Simple, usage-based pricing.
Free
$0
- Up to 50 checkouts / month
- Non-custodial, all 4 networks
- Signed webhooks
Pro
$19/mo
- Unlimited checkouts
- Everything in Free
- Priority support
Billed through your existing Zynost account's checkout — no separate payment system to manage.
Questions
How is this different from a custodial gateway?
Custodial gateways receive customer funds into their own wallet, then pay you out later on a schedule. Zynost Pay never receives anything — every address is derived from your own extended public key, so payments go straight to a wallet you control from the first block confirmation.
What's an xpub, and is it safe to share?
An extended public key. It lets us derive unlimited receive addresses that belong to your wallet, but it mathematically cannot be used to spend from it — no private key or seed phrase is ever involved. It's the same watch-only principle real hardware wallets use for address-book features.
What happens if a customer sends the wrong amount?
We accept anything at or above ~99.9% of the invoiced amount (to tolerate rounding noise) — an underpayment is left as pending so you can handle it manually; there's no automatic partial-fulfillment.
Do you support recurring billing?
Not yet — every checkout is a single one-time invoice today. You can call POST /v1/checkout again each billing cycle from your own backend to build recurring billing on top of it.
How do I move from Free to Pro?
Email us once you're ready — the Free plan's 50 orders/month is enough to fully evaluate the API before committing.
Start accepting crypto in minutes.
No custody, no payout wait, no separate payment infrastructure to trust.
Create a merchant account