Integrations
WHMCS
Let clients pay hosting, VPS, domain and SaaS invoices by card while you receive USDC.
Requirements#
- WHMCS 8.x
- PHP 7.2 or newer
- Your WHMCS installation must be reachable over HTTPS.
- A PayLio account with an API key and a Polygon wallet.
Install the module#
- 1
Get the module ZIP
Request the latest WHMCS module from our team on Telegram.
- 2
Upload the files
Extract the ZIP into your WHMCS root directory so the files merge into
/modules/gateways/. - 3
Activate the gateway
In the WHMCS admin, go to Configuration › System Settings › Payment Gateways and activate PayLio.
- 4
Configure and save
Fill in the settings below.
- 5
Pay a test invoice
Create a small invoice for a test client and pay it. The invoice is marked paid automatically.
Settings#
| Setting | Description |
|---|---|
| PayLio API URL | Leave the default https://paylio.org/api/payments/create. |
| PayLio API Key | Required. Create one in Dashboard › API Keys. |
| Merchant ID or Email | Your PayLio account email or Merchant ID. |
| Settlement USDC Wallet | Your Polygon wallet (0x…) that receives USDC. |
| Card Provider | multi (default) or a single provider ID, see Providers. |
| Fee Handling | Absorb the fee, or add it to the client's invoice. |
| Payment Gateway Title / Checkout Description | Text clients see on the invoice. |
| Enable Logging | Writes requests and webhooks to Utilities › Logs › Module Log. |
How invoices are updated#
When a client clicks Pay now, the module creates a PayLio payment and redirects to the checkout. After payment, PayLio sends a signed webhook to modules/gateways/callback/paylio.php. The module verifies it, confirms the payment via the API and adds the payment to the invoice. Recurring billing and automatic provisioning keep working as usual.
Webhooks are sent once
If the callback cannot reach WHMCS (maintenance mode, firewall, Cloudflare challenge), the invoice stays unpaid. Check the payment in your PayLio dashboard and apply it manually under the invoice's Add Payment tab.