linux-game-haptics-router

Routes Linux game force-feedback (rumble) into buttplug/Intiface toy vibration commands. An eBPF probe watches games writing FF effects to /dev/input/eventN via the EVIOCSFF ioctl, translates whatever they send (rumble/periodic/constant/ramp) into a vibration schedule, and streams it to a running Intiface/buttplug server.

Install

Grab the tarball for your architecture from the latest release and drop the binary in /usr/local/bin:

# amd64
curl -LO https://github.com/madrigal-eschat/linux-game-haptics-router/releases/latest/download/game-haptics-router-<tag>-linux-amd64.tar.gz
# or aarch64
curl -LO https://github.com/madrigal-eschat/linux-game-haptics-router/releases/latest/download/game-haptics-router-<tag>-linux-aarch64.tar.gz

tar xzf game-haptics-router-<tag>-linux-*.tar.gz
sudo install -m 755 game-haptics-router-<tag>-linux-*/game-haptics-router /usr/local/bin/game-haptics-router

Replace <tag> with the actual release tag (e.g. v1.2.0) shown on the releases page — GitHub doesn't support a version-agnostic asset URL.

Usage

Loading the eBPF probe and reading raw evdev nodes both need root. Start Intiface Central (or another buttplug server) first, then:

sudo game-haptics-router --ws-url ws://127.0.0.1:12345 --scale 0.8

ws://127.0.0.1:12345 is Intiface Central's default WebSocket address.

Other flags:

sudo game-haptics-router --list-devices   # print FF-capable evdev devices as JSON, then exit

sudo game-haptics-router --ws-url ws://127.0.0.1:12345 \
  --scale 1.0 \
  --device-map '{"usb-0000:00:14.0-1/input0": [0, 1]}'   # route one evdev device to specific toy indices; omit or use null to broadcast to every connected toy

While running, the global scale can be updated live by writing a JSON line to stdin:

echo '{"scale": 0.5}' | sudo tee /proc/$(pgrep game-haptics-router)/fd/0

(or just pipe it in directly if you're supervising the process yourself).

Caveats

• Only detects evdev force-feedback devices — anything a game drives through a different haptics path (e.g. DualSense adaptive triggers/haptics over its non-evdev HID report, or some kind of libusb-based direct-to-controller communication) is invisible to this tool. Adding support for additional feedback detection isn't out of scope, but it's also not currently a priority.
• Must be started before the game launches. The eBPF probe only sees EVIOCSFF calls that happen after it attaches — effects uploaded to a device before game-haptics-router is running are missed until the game re-uploads them (e.g. on a restart).
• No per-game or per-controller filtering yet — every FF-capable evdev device found on the system gets routed, and all captured effects across every process are translated and played. If you have multiple FF devices or games running at once, they'll all drive your toys.

Project setup & build

Workspace of three crates: linux-game-haptics-router (userspace daemon, built as game-haptics-router), linux-game-haptics-router-ebpf (the eBPF program), linux-game-haptics-router-common (shared types). See CLAUDE.md for the full architecture breakdown.

Building the eBPF program needs a nightly toolchain (for aya-build) plus bpf-linker, alongside the stable toolchain used for the rest of the workspace. --exclude linux-game-haptics-router-ebpf is required on every command below: that crate is #![no_std]#![no_main] with its own #[panic_handler] and can only compile through aya-build's cross-compile (invoked from linux-game-haptics-router's build.rs, which still runs and produces the real embedded bytecode regardless of the exclude) — building it directly as a normal workspace member links std and collides with its #[panic_handler].

rustup toolchain install nightly --component rust-src
cargo install bpf-linker

cargo build --workspace --exclude linux-game-haptics-router-ebpf          # debug build
cargo build --workspace --exclude linux-game-haptics-router-ebpf --release

Run the test suite:

cargo test --workspace --exclude linux-game-haptics-router-ebpf

Cross-compiling for aarch64 additionally needs the target and a cross linker:

rustup target add aarch64-unknown-linux-gnu
sudo apt install gcc-aarch64-linux-gnu   # Debian/Ubuntu
CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER=aarch64-linux-gnu-gcc \
  cargo build --workspace --exclude linux-game-haptics-router-ebpf --release --target aarch64-unknown-linux-gnu

Running the built binary (whether via cargo run or the installed binary) needs root, same as Usage above.

End-to-end tests

e2e/run.sh boots a QEMU VM and runs the full pipeline (real eBPF probe, real daemon, a virtual FF gamepad, and an in-process fake buttplug server) against a handful of gesture scenarios. See CLAUDE.md for details.