RMHook-Win

A Windows port of RMHook for the reMarkable Desktop application. This repo builds a proxy DLL that hooks Qt network APIs and redirects reMarkable cloud traffic to a self-hosted rmfakecloud server.

Overview

RMHook-Win intercepts the reMarkable Desktop app's Qt networking layer and patches outgoing requests to the configured host and port. It is designed for the Windows reMarkable Desktop client and uses a DLL proxy for paho-mqtt3as.dll.

Features

• Network request interception and redirection
• WebSocket connection patching
• MQTT URI modification for screen sharing features

Compatibility

Tested and working on:

• reMarkable Desktop v3.27.1 (released 2026-06-05)

Installation and usage

⚠️ For legal reasons, this repository does not include a pre-patched reMarkable app. However, the latest compiled dylib is available in the Releases section.

Auto installation

Run in a PowerShell terminal with administrator privileges:

irm https://raw.githubusercontent.com/NohamR/RMHook-Win/refs/heads/main/scripts/download-and-install.ps1 | iex

Manual installation

Step 1: Build or obtain the proxy DLL

Build the paho-mqtt3as-proxy project with Visual Studio using paho-mqtt3as-proxy.slnx, or use an existing paho-mqtt3as.dll built from this repo.

Step 2: Install the hook

Use the installer script from the scripts folder. Note: Run from an elevated PowerShell session. The installer script will request administrator privileges if needed.

From PowerShell:

.\scripts\install-hook.ps1 -Action install

Or with the batch wrapper:

.\scripts\install-hook.bat -Action install

If you want to install a custom DLL build:

.\scripts\install-hook.ps1 -Action install -SourcePath "C:\path\to\paho-mqtt3as.dll"

The script expects the Windows reMarkable install folder at:

C:\Program Files\reMarkable

Step 3: Restore the original DLL

To remove the proxy and restore the original paho-mqtt3as.dll:

.\scripts\install-hook.ps1 -Action restore

Configuration

When you pair the app the first time, the in-app browser will open my.remarkable.com to fetch a one-time pairing code, close the browser and enter the code from rmfakecloud direclty into the app prompt.

Config path:

%LOCALAPPDATA%\RMHook\config.json

The config is loaded on app startup and changes require a restart to take effect. It specifies the host and port for redirecting reMarkable cloud traffic.

Example config:

{
  "host": "your-server.example.com",
  "port": 443
}

If the config file does not exist, it will be created automatically with default values on first launch.

Troubleshooting

Hook install fails

• Confirm the reMarkable install path is C:\Program Files\reMarkable
• Run PowerShell as administrator
• Verify the source DLL exists and is a valid proxy build

App crashes or misbehaves

• Restore the original DLL with -Action restore
• Check the config file for valid JSON
• Make sure the host and port values point to a reachable rmfakecloud server

How it works

The project builds a proxy DLL for paho-mqtt3as.dll that re-exports all original functions. It hooks specific Qt network functions (QNetworkAccessManager::createRequest, QWebSocket::open and MQTTAsync_createWithOptions) to intercept and modify outgoing requests from the reMarkable Desktop app. The hooks redirect traffic to the configured host and port, allowing the app to communicate with a self-hosted rmfakecloud server instead of the official reMarkable cloud.

Credits

• MinHook: TsudaKageyu/minhook - API hooking framework used by the project
• rmfakecloud: ddvk/rmfakecloud - Self-hosted reMarkable cloud
• xovi-rmfakecloud: asivery/xovi-rmfakecloud - Original hooking information
• rm-xovi-extensions: asivery/rm-xovi-extensions - Extension framework for reMarkable, used as reference for hooking Qt functions
  • qt-resource-rebuilder
  • xovi-message-broker
• dll-proxy-generator: maluramichael/dll-proxy-generator - Used to generate the initial proxy DLL code

License

This project is licensed under the MIT License. See the LICENSE file for details.

Disclaimer

This project is not affiliated with, endorsed by, or sponsored by reMarkable AS. Use at your own risk. This tool modifies the reMarkable Desktop application and may violate the application's terms of service.

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.