Notes

Unlike E4MC, StealthPipe requires both clients to have the mod installed, since it completely rewrites Minecraft's networking to work with WebSockets in order to achieve the benefits listed above.

Version 3.0.0 introduces a parallel connection architecture, enabling the relay to utilize multi-core processing for significantly faster packet forwarding and improved horizontal scalability.

Version 5.0.0 introduces a packet batching system (enabled by default, can be disabled) that batches packets that are sent at around the same time (1ms difference). This measure reduces the packets per second count by around 10x (500 packets per second to 50 packets per second on average). The lower packets per second count allows the connections to have a higher reliability and less random drops from firewalls. However, this brings an additional 8ms to 30ms of ping. This feature can be disabled in the mod config. As of version 5.0.1, the additional latency is almost gone, but an 8-30ms added ping can sometimes still be present in some cases (can be reduced by rejoining).

Version 6.0.0 introduces peer-to-peer connections when possible (WebRTC), reducing ping by up to 50%!

Backend source code can be found here: https://github.com/CariLT01/stealthpipe-relay

More Important Notes

• 2.1 MB packet size limit: The public relay enforces a 2.1 MB packet size limit for stability. Since Vanilla Minecraft defaults to a 2 MB limit, this limit is normally fine when playing with a minimal amount of mods. However, this means that mods like Packet Fixer or XXL Packets will not work on the public relay; the relay will disconnect the client before the mod can bypass the limit.

  If your modpack requires larger packets, you must host your own relay and adjust the limit in the source code.

• Throttling if consuming too much bandwidth: To protect the server's bandwidth usage, your connection may be throttled or disconnected if you are sending too much data. The threshold depends on the duration of sustained high bandwidth usage and the number of clients connected to the current world. Normal vanilla gameplay should never trigger this. You may resolve this by hosting your own relay, see the self-hosting section above.

• Proof of Work: To prevent automated Botnets from spamming and crashing the free public relay (DDoS protection), the server requires a 'Handshake Ticket.' The client generates this ticket by solving a small mathematical puzzle (SHA-256 hashing), also called Proof of Work. This ensures that every room creation is backed by a real computer's effort, making it extremely difficult for a script to create 10,000 rooms per second.

The public relay may get upgraded if this mod starts becoming too popular.

Why?

In many network environments, peer-to-peer connections are blocked and most ports other than 443 are restricted, like in airports and hotels. Since Minecraft’s Open to LAN relies on direct connections and non-443 ports, it simply doesn’t work in these conditions.

Also, in many of these places, QUIC (technology used behind the popular e4mc mod) is also blocked, but e4mc fundamentally relies on it.

StealthPipe solves this by tunneling LAN multiplayer traffic through secure WebSockets over port 443, allowing players to connect where traditional LAN hosting (and e4mc) would normally fail.

StealthPipe is a protocol-specific relay; it only handles Minecraft game packets and cannot be used as a general-purpose VPN or proxy. It also cannot connect to public servers such as Hypixel.

How?

It achieves this by sending Minecraft traffic over WebSockets, making it appear as normal browser traffic. This mod is similar to e4mc, but it routes traffic through WebSockets instead of using QUIC.

Technical overview can be found here: https://github.com/CariLT01/stealthpipe-relay/blob/main/TECHNICAL.MD

Usage

1. Host: Press "Open to LAN" and share the generated link or code.
2. Join: Guests enter the code to join.
3. Requirement: All players must have the mod installed.

You can configure which relay to use in the mod settings. Use a third-party relay or host your own if needed. The relay backend is open-source and MIT-licensed. The default relay in this mod is completely free to use.

Self-Hosting a Relay

It is highly recommended to host your own relay for control and stability. The relay is designed to be easily portable and can run everywhere, regardless of the environment by using Docker containers. The entire relay consists of three files. StealthPipe relay is multithreaded, lightweight, and portable. It uses less than 32 MB of memory.

The guide is available here: https://github.com/CariLT01/stealthpipe-relay/blob/main/HOSTING.md

Alternative relays

The default relay hosted on Render.com can sometimes be slow and unreliable depending on external factors. The default relay is hosted on Render's free tier as a proof-of-concept; users are encouraged to self-host for production-level stability. Explore these alternative relays if you have issues with the default one:

• Default (sometimes offline): https://mcpipeservice-go.onrender.com/
• HF Space Relay (backup relay, probably slower and higher ping, may be offline): https://publicuser22222222-mcpipeservice-go.hf.space

Mod Compatibility

Krypton may cause some issues with StealthPipe. Although it remains mostly usable if you accept the occasional disconnects.

This mod cannot be installed on a dedicated server. Otherwise, it should be compatible with most content mods.