How to Create a Free FiveM Server License Key (Cfx.re Keymaster)

Running a FiveM server requires a license key issued by the Keymaster, the official Cfx.re system. Without it, FXServer refuses to boot with the message invalid license key specified and the server won’t appear on the public list. The good news: there is a free key. All you need is a Cfx.re forum account and the IP address of the server where FXServer will run.

This tutorial is for anyone setting up their first FiveM server — whether on a VPS, dedicated server, or local test environment. We’ll cover Keymaster registration, key generation tied to the correct IP, configuration in server.cfg, and the most common validation errors that appear in the first few minutes of operation.

Prerequisites

Before generating the key, make sure you know which IP will host the server. The license is bound to that address — if you generate it with the wrong IP, you’ll need to update the binding afterward.

If you don’t have a server yet, decide where it will run before continuing. The key supports three binding modes:

For production, use a fixed IP. Localhost works for development on your own machine. Wildcard is functional, but Cfx.re may revoke wildcard keys used on public servers with high player counts.

Create a Cfx.re Forum Account

Keymaster authenticates via the official Cfx.re forum — you don’t create an account directly on the key panel. Instead, you register on the forum, which acts as SSO for the entire FiveM ecosystem.

https://forum.cfx.re/

https://keymaster.fivem.net/

Generate the License Key in Keymaster

With an active account, key generation takes under a minute. The system allows up to roughly 9 keys per account for free — enough for multiple servers or staging environments.

curl -4 ifconfig.me

cfxk_XXXXXXXXXXXXXXXXXXXXX_YYYYYYY

Configure the Key in server.cfg

The key must be declared in the configuration file that FXServer reads during boot. By default, this file is located at ~/server-data/server.cfg on Linux or in the server folder on Windows.

nano ~/server-data/server.cfg

sv_licenseKey cfxk_XXXXXXXXXXXXXXXXXXXXX_YYYYYYY

cd ~/server-data
bash ~/fxserver/run.sh +exec server.cfg

Verification

A server with a valid key displays specific messages in the console during boot. You confirm success by observing these logs.

Look in the console for a sequence similar to:

Authenticating with [Cfx.re]...
Server license key authentication succeeded.
Server is now available on the server list.

If authentication fails, FXServer exits with the message Invalid license key specified, or RCON password not set. In that case, review the key and the bound IP.

You can also verify via FiveM’s public API whether the server appears listed. Replace IP:PORT with your endpoint:

curl http://IP:PORT/info.json

The response should contain a JSON with vars, version, and resources. If it returns a connection error, the issue is firewall or port — not the key.

Troubleshooting

Error: invalid license key specified

The most common cause is a wrong IP in Keymaster. Go back to the dashboard, edit the key (pencil icon), and update the IP. The change is instant, but FXServer must be restarted to revalidate.

Second cause: the key was copied with an invisible character (space, line break). Delete the entire line in server.cfg and re-enter it, or use echo to ensure a clean format:

echo 'sv_licenseKey cfxk_YOUR_KEY_HERE' >> server.cfg

Error: license key has expired or been revoked

Keymaster keys don’t expire by time, but are revoked in three scenarios: public leak detected by Cfx.re, terms of service violation (commercial use without adequate licensing for large servers), or manual deletion by the account owner. Generate a new key from the dashboard.

Server starts but doesn’t appear on the public list

In this case, the key worked, but there’s another issue. Check that sv_endpoints is configured correctly and that port 30120 (UDP and TCP) is open in the firewall:

sudo ufw allow 30120/tcp
sudo ufw allow 30120/udp

The server may take up to 2 minutes to appear on the public list after the first successful boot.

Next Steps

With the key configured, the server is technically operational. From here, consider:

• Setting up txAdmin to manage the server via web (start/stop, remote console, backups)
• Enabling OneSync if you plan for more than 32 simultaneous players
• Adjusting sv_maxClients and performance parameters in server.cfg
• Configuring essential resources: ESX or QBCore for roleplay frameworks
• Implementing automated backups for your MySQL database and resources folder

If you’re taking the server to production with more than 32 slots, a Hostini VPS with NVMe storage and low latency to the Cfx.re backbone reduces tickrate drops during peak hours — FiveM’s typical bottleneck is database I/O and single-thread CPU, both addressed by plans with dedicated vCPU.