ShyFrpc

ShyFrpc

Open your LAN world to the internet without touching your router.

ShyFrpc is a client-side Minecraft mod that launches a local frpc
process from inside the game, so you can forward your singleplayer LAN world through an
FRP tunnel. No port forwarding, no NAT configuration, no external launcher — just a slash
command.

Built for the exact problem every host hits: you want to play with a friend, you open your
world to LAN, and then you realize your ISP put you behind CGNAT and port forwarding is
simply not an option.

Features

• No port forwarding. Works behind CGNAT and carrier-grade NAT.
• Pure client-side. Nothing to install on the other player’s side. They just need your
  tunnel address.
• Two modes. Point it at your own frpc config file, or use SakuraFrp credentials with
  a single command.
• Live output. Everything frpc prints goes straight to your in-game chat and to
  logs/latest.log, so you can see the tunnel address and spot auth failures immediately.
• Auto-start. Turn it on and frpc starts the moment you open your world to LAN.
• Automatic cleanup. Close the LAN room, leave the world, or quit the game — frpc is
  stopped for you. No zombie processes.
• English and Chinese localization.
• No third-party runtime dependencies.

Requirements

For SakuraFrp mode you also need a SakuraFrp account with a
tunnel already created in their panel.

Installation

1. Download the jar matching your mod loader and drop it in your mods folder.
2. Install frp and note the full path to
   frpc.exe / frpc.
3. Launch the game, load a singleplayer world, and configure ShyFrpc with the commands
   below.
4. Share the tunnel address that appears in chat with your friends.

Commands

All commands require operator permission. In singleplayer you have it by default.

Usage

Using your own frpc config

If you already have a working frpc setup, point ShyFrpc at it:

/shyfrpc set app "C:\frpc\frpc.exe"
/shyfrpc set toml "C:\frpc\minecraft.toml"
/shyfrpc mode default
/shyfrpc on

ShyFrpc runs:

frpc.exe -c C:\frpc\minecraft.toml

The -c path is resolved to an absolute path before launch, and frpc’s working directory
is set to your game directory — so relative references inside your .toml still resolve
the way you expect.

Using SakuraFrp

Create a tunnel in the SakuraFrp panel, then copy the user token from your account page
and the tunnel ID from the tunnel list:

/shyfrpc set app "C:\frpc\frpc.exe"
/shyfrpc set sakura token 123
/shyfrpc mode sakura
/shyfrpc on

ShyFrpc runs:

frpc.exe -f token:123

Fully automatic

Once configured, this is all you need to do each session:

/shyfrpc auto-start true

Then just press Escape → Open to LAN → Start LAN World. frpc starts on its own,
and stops when you close the room or leave the world.

Configuration file

Settings are stored in config/shyFrpc/config.yaml and written by the commands above.
You can edit the file by hand — it is re-read every time you run a /shyfrpc command, so
no restart is needed.

app: "C:\\frpc\\frpc.exe"
toml: "C:\\frpc\\minecraft.toml"
mode: default
sakura-token: ""
sakura-tunnel: ""
auto-start: false

If the file is ever corrupted, ShyFrpc falls back to defaults and logs a warning — it will
never delete your configuration for you.

Lifecycle

ShyFrpc treats frpc as a child process of Minecraft:

Stopping is graceful: frpc gets a normal termination signal, and is force-killed only if it
has not exited within three seconds.

Troubleshooting

“frpc executable not found”
The path is resolved relative to your game directory if it is not absolute. Run
/shyfrpc status — it prints the fully resolved path and marks it [missing] if it does
not exist.

The tunnel connects but my friend cannot join
Start the LAN world before or right after running /shyfrpc on — frpc has nothing to
forward until the world is published to LAN. Also make sure the tunnel’s remote port
matches the port shown in the “Local game hosted on port …” chat message.

frpc output shows an authentication error
Double-check the token and tunnel ID with /shyfrpc status — the token is masked there, so
set it again if you are unsure. Make sure the tunnel exists and is not disabled in the
SakuraFrp panel.

Nothing appears in chat
frpc output is forwarded to the player only while you are in a world. If you started frpc
and then returned to the main menu, check logs/latest.log instead.

Building from source

./gradlew build

The jars land in fabric/build/libs, forge/build/libs and neoforge/build/libs.

License

Apache License 2.0