Non-custodial
Funds go to your wallet, from your xpub. We hold no key of yours and no balance of yours.
Payment engine
Crypto payments that go straight to your wallet.
A non-custodial crypto payment processor for subscriptions and one-time sales. Funds land at addresses derived from your own xpub. We never hold them.
- Non-custodial
- USDT and USDC
- 7 networks live
- 0.5% or 99 USD/month
Money flow
Payer, then your wallet.
The payer picks a network and sends USDT or USDC to a fresh address of your xpub. The processor watches the chain, confirms the amount and signs a webhook to your server. No balance sits with us.
What it is
A processor, not a custodian
zenGELDMASCHINE invoices, watches the chain and reports the result. Your keys and your money stay yours.
Subscriptions and one-time sales
Renewals, grace periods, proration and a price per subscription, or a single invoice for a single sale.
Integrates in an afternoon
Five REST routes and signed webhooks. Use the hosted widget or draw the checkout yourself.
How it works
From form to first invoice
You pay with the same processor you are about to use.
- Fill in the connect form. Business name, webhook URL and your xpubs.
- Make your first payment. Make your first top-up (from 20 USD) or pay the first month, in USDT or USDC, through this same processor.
- Receive your access. Your API key, webhook secret and instructions, shown once.
- Integrate. Follow the docs and create your first invoice.
Payments go to your wallet. The 0.5% fee is taken from your prepaid balance.
Networks and assets
Live now
Only what is live is listed.
| Network | Assets |
|---|---|
| Ethereum | USDTUSDC |
| Polygon | USDTUSDC |
| Arbitrum | USDTUSDC |
| Avalanche C-Chain | USDTUSDC |
| Optimism | USDC |
| Base | USDC |
| TRON | USDT |
| BSC | Coming soon |
Features
Built for correct accounting
Every line below is code that runs in production.
The payer picks the network
One invoice carries every option: each network and asset, with its own address and exact amount.
Two ways to check out
Embed the hosted widget, themed to your brand, or build your own UI on the API. Both are permanent.
Signed webhooks with retries
Every delivery is signed. Failures retry with backoff and are kept in a dead-letter list.
Subscriptions and one-time payments
Recurring plans, single sales, proration on plan changes and a price per subscription.
Exact-amount accounting
Partial payments and overpayments are reported as they are, never rounded away.
Reorg-safe confirmations
A payment counts only when it is final. If the chain view diverges, the processor halts instead of guessing.
Live widget
This is the real checkout
The hosted widget in demo mode. Pick a network, switch the theme. Your page passes colours as tokens and keeps its own look.
Prefer your own screen? Read the invoice over the API and draw the payment page yourself.
Pricing
Two ways to pay
Pick the one that fits your volume. No volume limits either way, and funds go straight to your own wallet.
Pay as you go
0.5% of settled payments
Taken from a prepaid balance. Top up from 20 USD in USDT or USDC through the same processor; the first top-up is made in the Connect form. No monthly fee, no connection fee, no volume limits. When the balance runs out, new invoices pause until you top up, and you get a low-balance webhook in advance.
Fixed monthly
99 USD / month
Prepaid in USDT or USDC through the same processor. 0% of payments, no volume limits. It pays off above about 20,000 USD of volume per month. If a renewal is not paid, new invoices pause until it is.
Pick your option in the Connect form; your API key, webhook secret and integration instructions appear right after the first payment.
Non-custodial: payments land at addresses derived from your own xpub, and we never hold your funds.
FAQ
Short answers
Who holds the money?
You do. Payments go to addresses derived from your xpub. We never have your private keys.
What are the fees?
Two options. Pay as you go: 0.5% of every settled payment, taken from a prepaid balance you top up from 20 USD. Fixed monthly: 99 USD per month prepaid, 0% of payments. There is no connection fee. Network gas is paid by the payer.
Refunds?
Refunds are manual: you send them from your wallet and record them.
Which wallets work?
Any wallet that exports a BIP44 account xpub. Verify the derived addresses before you go live.
Can I test first?
Yes. The demo widget above runs in demo mode, and the docs describe test invoices.
What if I stop paying?
Pay as you go: when the balance runs out, new invoices pause until you top up, and a low-balance webhook warns you in advance. Fixed monthly: if a renewal is not paid, new invoices pause until it is.