WHMCS Plugin

Requirements

PHP >= 7.4 (with curl, json and openssl extensions; bcmath recommended)
WHMCS >= 8.0

Description

Accept payments in Bitcoin, Bitcoin Cash, Litecoin, Ethereum, USDT and many other cryptocurrencies and tokens directly to your crypto wallet, without any sign-ups or lengthy processes. All you need is to provide your crypto address.

Let your customers pay their invoices with crypto

The CryptAPI module extends WHMCS, allowing your customers to pay their invoices in cryptocurrency directly on the invoice page. The customer picks a coin, the module generates a payment address for the exact invoice value and shows it with QR codes and live payment progress — and the invoice is marked as paid automatically as soon as the payment is confirmed on the blockchain.

Accepted cryptocurrencies & tokens include:

• (BTC) Bitcoin
• (ETH) Ethereum
• (BCH) Bitcoin Cash
• (LTC) Litecoin
• (TRX) Tron
• (BNB) Binance Coin
• (USDT) USDT
• (SHIB) Shiba Inu
• (DOGE) Dogecoin
• (POL) Polygon
• (SOL) Solana

Value conversion

Invoices are charged in their own WHMCS currency; the module automatically converts the invoice value to the cryptocurrency your customer chooses, using real-time exchange rates, and can keep re-quoting the rate on a schedule you control while the customer has not paid yet.

Note: CryptAPI will not exchange your crypto for FIAT or other crypto, just convert the value.

Why choose CryptAPI?

CryptAPI has no setup fees, no monthly fees, no hidden costs, and you don't even need to sign up! Simply set your crypto addresses and you're ready to go. As soon as your customers pay, we forward your earnings directly to your own wallet.

CryptAPI has a low 1% fee on the transactions processed. No hidden costs.

Installation

1. Download the latest whmcs-cryptapi-vX.Y.Z.zip from the Releases page
2. Extract the archive into your WHMCS root directory. It mirrors the WHMCS folder layout, so the files land exactly where they belong:

<whmcs>/modules/gateways/cryptapi.php
<whmcs>/modules/gateways/callback/cryptapi.php
<whmcs>/modules/gateways/cryptapi/…

3. All done! There is no database migration step — the module sets itself up automatically.

Updating

Extract the new release over the existing files, overwriting them. As always, ensure you backup your site just in case.

Configuration

1. Log in to your WHMCS admin area
2. Go to Configuration → Apps & Integrations, select the Payments category and choose CryptAPI Cryptocurrency (on older versions: Setup → Payments → Payment Gateways)
3. Activate the gateway
4. Input your addresses next to the cryptocurrencies you wish to accept, and leave the others empty. This is where your funds will be sent to, so make sure the addresses are correct
5. Click "Save Changes"
6. All done!

Frequently Asked Questions

Do I need an API key?

No. You just need to insert your crypto address for the cryptocurrencies you wish to accept. Whenever a customer pays, the money will be automatically and instantly forwarded to your address.

If you prefer an API-key based setup with dashboard-managed addresses and a hosted checkout page, use the BlockBee module for WHMCS instead.

How long do payments take before they're confirmed?

This depends on the cryptocurrency your customer uses. Bitcoin usually takes up to 11 minutes, Ethereum usually takes less than a minute.

How does WHMCS know an invoice was paid?

CryptAPI notifies your WHMCS installation through a cryptographically signed callback for every payment it sees — first as pending, then as confirmed. The module verifies the RSA signature against CryptAPI's public key, matches the notification to the exact payment session it created, and only records the payment once the confirmed total covers the invoice — duplicates and forgeries are rejected automatically.

What happens if a customer underpays or pays in several transactions?

Partial payments are tracked per transaction and shown to the customer on the invoice page, together with the remaining amount still owed. The invoice is only marked paid once the full converted value is confirmed. You can optionally allow a small underpayment tolerance (0–10%) in the module settings to absorb exchange withdrawal fees.

Is there a minimum for a payment?

Yes, the minimums change according to the chosen cryptocurrency and can be checked here. If the invoice total is below the chosen cryptocurrency's minimum, the customer is asked to pick a different coin.

Does the module support refunds?

No. Cryptocurrency payments are not reversible, so WHMCS' "Refund through gateway" option stays disabled for CryptAPI transactions. Refunds, if you choose to give them, are manual payouts handled outside WHMCS.

Changelog

1.0.0

• Initial release.