VirtFusion billing and automation, without a WHMCS module
VirtFusion runs your KVM hypervisors; invoices, payments and renewals come from the billing system you connect to it. The FluxBilling plugin is that billing side: a paid order creates the customer’s VirtFusion account, builds the server from the package you sold, and puts power, console, reinstall and a one-click login to the VirtFusion panel in the client area. Unpaid invoices suspend the server; termination deletes it.
The plugin is free. VirtFusion licensing stays between you and VirtFusion.
The VirtFusion plugin is listed at no charge on the FluxBilling marketplace and installs on every tier. FluxBilling plans are priced by the clients you bill, and by bare-metal servers if you sell those — not by the virtual servers VirtFusion runs for you.
You keep your VirtFusion licence and your hypervisors exactly as they are. The plugin only needs an API token.
- Plugin price
- Free
- Available on
- Every tier
- Authentication
- Admin API token
- Guests
- KVM virtual servers
- Customer link
- VirtFusion user per customer
- Plugin version
- 1.1.1
From a paid invoice to a built VirtFusion server
VirtFusion places the server on a hypervisor inside the group the customer chose. The plugin handles the account on either side and cleans up after itself when a build fails.
- 01OrderThe customer picks a location and an operating system from the ones you allowed on the product, and a hostname. The root password is generated and delivered with the welcome email.
- 02Find or create the VirtFusion userEach FluxBilling customer is linked to one VirtFusion user through VirtFusion’s external relation ID. An existing user is reused; a missing one is created.
- 03Collision checkIf a VirtFusion user is found but its email belongs to someone else, the order stops instead of attaching a server to the wrong account.
- 04Allocate the serverThe server is allocated from the package on the product, in the chosen hypervisor group, with an IPv6 range attached if you enabled it.
- 05BuildVirtFusion installs the operating system. If the build fails, the plugin releases the allocated server so it does not linger unbilled.
- 06DeliverServer details — addresses, operating system, location — appear in the client area, and the customer gets FluxBilling’s welcome email rather than VirtFusion’s unless you switch VirtFusion’s emails on.
What the customer can do with a VirtFusion server
Staff side. Staff see the same actions plus the build state and the access credentials, and can open the customer’s VirtFusion session from the admin panel.
A VirtFusion package becomes a product
VirtFusion packages already hold the CPU, RAM, disk and traffic sizes. A FluxBilling product picks one and decides what the customer may choose at checkout.
| Setting | What it decides |
|---|---|
| Package | The VirtFusion package — the CPU, RAM, disk and traffic preset — this product builds. |
| Available locations | The hypervisor groups the customer may choose from. VirtFusion places the server on a node inside the chosen group. |
| Available OS images | The operating system templates offered for this package. |
| Allow OS / location selection | Whether the customer chooses at checkout, or gets the first allowed option. |
| Hostname template | Generates hostnames from the service number with {{id}}. Empty lets the customer choose. |
| Assign IPv6 | Asks VirtFusion to attach an IPv6 range at build time. The hypervisor group needs an IPv6 block. |
| Swap | The swap space the build creates, in VirtFusion’s own sizes. |
Connect VirtFusion in four steps
- 01Create an API tokenIn VirtFusion: System → API → Create Token. If you use the token’s Access field, lock it to the IP address FluxBilling connects from.
- 02Install the pluginInstall VirtFusion from the marketplace in your FluxBilling admin panel. It is free.
- 03Enter the connectionPanel URL, token and how customers are linked — the fields on the right.
- 04Build a product and test itPick a package, locations and operating systems, then place one test order before selling. The customer link cannot be changed once real customers exist, so test first.
- VirtFusion panel URLThe panel’s HTTPS address, without /api/v1 and without a trailing slash.
- API tokenAn admin API token from System → API.
- Customer linkHow customers map to VirtFusion users. “Customer ID” sends the FluxBilling customer ID as VirtFusion’s relational identifier and needs VirtFusion 6.1 or newer; a numeric legacy mode exists for older panels.
- Let VirtFusion email customersOff by default, so customers get one welcome email — FluxBilling’s — instead of two.
- Termination graceMinutes VirtFusion waits before destroying a terminated server: 0 to 43,800. A window to undo a mistaken termination inside VirtFusion.
The invoice drives the server
| When | The plugin |
|---|---|
| Invoice paid | Creates or reuses the VirtFusion user and builds the server. |
| Overdue past your grace period | Suspends the server in VirtFusion. |
| Paid after suspension | Unsuspends it. |
| Upgraded | Moves the server to the new product’s VirtFusion package. |
| Terminated | Deletes the server, after the termination grace you set. A server already gone is treated as done, not as an error. |
Grace periods, reminders and the order in which renewals, payments and suspensions run are platform settings shared by every service — see Billing and Provisioning.
What it does not do
- Backups and snapshots are not offered through the plugin; manage them in VirtFusion.
- IP addresses come from VirtFusion’s own pools, not from FluxBilling’s IPAM.
- The “Customer ID” link needs VirtFusion 6.1 or newer. Verify one order on a test product first — the link format cannot be changed once customers exist.
VirtFusion and FluxBilling, answered
- What billing software works with VirtFusion?
- Any billing system with a VirtFusion module. FluxBilling ships one as a free marketplace plugin, so billing, the client area and provisioning live in one product instead of WHMCS plus a separately maintained module.
- Do I still need a billing system with VirtFusion?
- Yes. VirtFusion is the control panel for hypervisors and servers. Invoicing customers, taking payments, renewals and suspension for non-payment are handled by the billing system connected to it — with this plugin, FluxBilling.
- What does the VirtFusion plugin cost?
- Nothing. It is free on the FluxBilling marketplace and installs on every tier. Your FluxBilling plan is priced by clients, not by servers.
- Can customers log in to VirtFusion directly?
- Yes. “Open control panel” signs them in with a short-lived token, after the plugin checks the server belongs to the customer asking.
- Which VirtFusion version do I need?
- The default customer link uses VirtFusion’s relational identifier, added in VirtFusion 6.1. Older panels can use the numeric legacy mode.
- What happens to a server when the customer stops paying?
- It is suspended in VirtFusion once the invoice passes your grace period, and unsuspended when it is paid. Termination deletes it after the termination grace you configured.
VirtFusion is a trademark of its respective owner. FluxBilling is not affiliated with or endorsed by its owner; the name is used only to say which software the plugin connects to. Plugin facts read from plugin version 1.1.1, September 2026.
Around the VirtFusion plugin
- All pluginsEvery provider, gateway and notification plugin — each free on the marketplace.
- Proxmox VE pluginThe other common home for KVM hosting, cloned from cloud-init templates.
- SolusVM 2 pluginFor fleets still on SolusVM 2 — plans, locations and images per product.
- ProvisioningHow a paid order becomes a running service, for every provider.
- Hypervisor support comparedWhich panels each hosting billing platform documents, and in which edition.
- PricingTiers from Lite to Business, and the 14-day refund.
Try it on your own data. Refund inside 14 days if it’s not the fit.
Pick a tier and provision a tenant in under two minutes — isolated K3s namespace, your own database, the full product. If FluxBilling isn’t the right fit inside 14 days, open a ticket and we’ll refund the subscription. No sales call, no qualification gate. Want to look around first? The live demo opens the admin and client panels with sample data, no signup.
- 01.< 1 minPick a tierLite from €4.95/mo. Upgrade later, no migration.
- 02.< 2 minProvision the tenantIsolated K3s namespace + your own PostgreSQL database. Full product, your data.
- 03.d0 — d14Refund inside 14 daysNot the fit? Open a ticket within 14 days and we refund the subscription. No questions, no qualification gate.