A crypto wallet payment gateway integration connects software your team does not run. The payer's wallet signs the transfer, and the blockchain confirms it. Your part is everything around those two events: creating the charge, sending the payer to a page where they can pay, learning the result, and recording it against the right order.

EukaPay's API covers that sequence with the invoices endpoint, a hosted payment page, and signed webhooks, so your code does not have to generate addresses or watch a chain. The seven steps below follow the order we would build it in, from a staging account to a first payout, with the fields each step depends on.

Three systems take part in every payment. The payer's wallet holds the cryptocurrency and signs the transfer. The gateway turns the order into a payment request, shows the payer where to send funds, and watches for confirmation. Your order system decides what was bought and whether it counts as paid.

The integration is the set of calls and events between the gateway and your order system. With a hosted payment page, the payer sends from the wallet they already use, so your checkout does not need a wallet SDK. Our

crypto payment gateway API

guide covers the full integration surface. This post covers the order you build it in.

Each step depends on the one before it, so build them in this order.

EukaPay runs two environments, production and staging. The staging environment uses the same exchange rates as production and accepts testnet cryptocurrencies. You create a separate account on staging, and the team approves that registration manually. The base URL for each environment is in the

API documentation

. Our guide to

testing crypto payments in a sandbox

covers testing before go-live.

Every request carries your API key in the

header. You generate the key after you sign up, complete verification, and provide your legal business information. Keep the key on your server, so it never reaches the browser that renders your checkout.

The invoice is the charge. Two fields are required:

and

, which points at a fiat currency on the Supported Currencies page. The fields that matter for this integration are these:

sets whether you receive fiat or crypto for this invoice.

holds your own references and is not shown to the payer, so your order ID can travel with the invoice. Send an

header on the request. If the call times out, a retry with the same key can return the original result instead of creating a second invoice.

The response carries the fields your order system should store:

Save the invoice

against your order ID. Every webhook in step 5 refers back to it.

The

opens EukaPay's hosted payment page. The payer completes the payment there from their own crypto wallet. Once the payment completes, the page sends the payer back to your

. Treat that redirect as navigation only, and mark the order paid from the webhook in step 5.

Add your webhook endpoint in the merchant dashboard under Settings, Integrations, Webhooks. Each payment event carries

,

,

,

, and

. Match on

to find the order.

If a delivery fails, EukaPay retries every 20 minutes for up to 2 hours. If your endpoint processes an event but the response fails, the same event can arrive again. Store the

of each event you process, so a repeat delivery is recognized and skipped.

Each webhook carries an

header. Your server computes an HMAC SHA-512 hex digest of the raw payload with your secret key and compares the two. Compute the digest before parsing the body, because a re-serialized payload may not match. Reject any event whose digest does not match.

If the integration also pays people, the same account sends crypto payouts. Fund the payout balance with a transfer from your main balance, or with a fiat deposit. The Create Crypto Payout endpoint creates one payout per request. Your code sets the asset and the network on each payout, from USDC, USDT, ETH, and BTC on Ethereum, Tron, and Bitcoin. To pay a whole recipient list at once, upload it as a CSV file in the merchant dashboard.

The

event includes

,

, and

, which is the join your reconciliation needs. Our

stablecoin payouts

guide covers the payout side in more depth.

The requested amount takes into account your transaction tolerance settings in the merchant dashboard. The

and

events complete the payout lifecycle, and the full payloads are in the

API documentation

.

A direct integration makes sense when payments have to live inside your own product. A store running on WooCommerce or Shopify can install EukaPay's plugin for that platform instead of building a direct integration. Our guide to

accepting crypto payments on Shopify

walks through that route. For the wider build, see our guide to how to

integrate crypto payments

in an order that avoids rework.

Every step above uses documented EukaPay endpoints: invoices, customers, balance transfer, and crypto payouts. The

API documentation

covers each request and every webhook payload. Our

crypto payments API

guide explains what each endpoint is for.

EukaPay does not issue stablecoins and is not the chain infrastructure layer. If your product has to give your own users wallets, that is a separate build from this integration. For a business taking payments and paying out, EukaPay's API covers the sequence from invoice to settlement. Our guide to

choosing a crypto payment gateway with an API sandbox

covers what to test before you commit.

EukaPay gives you instant crypto-to-fiat conversion at a locked exchange rate to remove your exposure to crypto price swings, support for most major cryptocurrencies, and settlement in USD, EUR, GBP, and CAD to your bank account. EukaPay locks the exchange rate on every conversion by default, on pay-ins and on payouts. A crypto payment confirms on-chain, so protection against chargebacks is a property of the payment method.

Build the seven steps in staging first, in the order above, and move to production once the webhook handling passes. EukaPay is the gateway we would put behind that integration, because the same account takes the payment, settles it, and sends the payout.

Read the

API documentation

for the invoice, customer, balance transfer, and crypto payout endpoints. Then

create an account

, open a staging account, and build the first invoice there.

What is a crypto wallet payment gateway integration?

It is the set of API calls and webhook events that connect a crypto payment gateway to your order system. The payer's wallet sends the funds, and your integration records the result against the right order.

Does my customer need a specific crypto wallet to pay?

No. The payer opens EukaPay's hosted payment page and sends the transfer from the wallet they already use.

How do I know a crypto payment has been completed?

EukaPay sends a

webhook when the sum of payments for the invoice matches the requested amount. Mark the order paid from that event, not from the redirect.

What happens if a customer underpays a crypto invoice?

EukaPay sends a

webhook, and the invoice status reads Underpaid. EukaPay takes your transaction tolerance settings into account when it compares the payment to the requested amount.

How do I stop duplicate invoices when a request times out?

Send an

header on the create request. A retry with the same key returns the original result. Keys can be removed once they are 24 hours old.

Can I test the integration with testnet cryptocurrencies?

Yes. EukaPay's staging environment accepts testnet cryptocurrencies and uses the same exchange rates as production.

Which cryptocurrencies can customers pay with?

Most major cryptocurrencies like BTC, ETH, LTC, SOL, USDC, USDT on the pay-in side.

Can crypto payments settle to my bank account?

Yes. Set

to fiat, and EukaPay settles to your own bank account in USD, EUR, GBP, or CAD.