Integrations
WHMCS
Let clients pay hosting, VPS, domain and SaaS invoices by card while you receive USDC.
Requirements#
- WHMCS 8.x
- PHP 7.4 or newer with cURL
- The WHMCS cron must run (it re-checks open payments).
- 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
Download the latest version from the WHMCS module page.
- 2
Upload the files
Extract the ZIP into your WHMCS root directory so the files merge into
/modules/gateways/and/includes/hooks/. - 3
Activate the gateway
In the WHMCS admin, go to System Settings › Payment Gateways › All 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 |
|---|---|
| Display Name / Description | Text clients see on the invoice. English and German texts are included. |
| API key | Required. Create one in Dashboard › API Keys. The connection is checked when you save. |
| Payout wallet (optional) | A Polygon wallet (0x…) for these invoices. Empty uses the wallet from your PayLio dashboard. |
| Payment provider | All providers (the client chooses) or one fixed provider, see Providers. |
| Processing fee | Included in your price, or added to the client's total. |
| Show payment icon / Custom icon URL | The card icon on the invoice, or your own https image. |
| Advanced | API base URL (leave the default) and debug logging 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.
A missed webhook is caught
If the callback cannot reach WHMCS (maintenance mode, firewall, Cloudflare challenge), the WHMCS cron re-checks the payment for up to a week. On the invoice you can also click Check PayLio status in the PayLio box.After paying, the client is sent back to the invoice (after 5 seconds, or at once with the Back to button). The invoice shows its own status; arriving there never marks it paid.