With the recent uprise in games being reverse engineered and decompiled using AI I decided to reverse engineer STEEPs server with a combination of decompiling the game and capturing the games traffic. Here is the repo: https://github.com/SomeRandomNiko/powder
Right now it provides most of the functionality that the normal STEEP servers provide, including multiplayer (currently only freeroam, not multiplayer matchmatking).
Basically you can download the Powder launcher from the latest release. It's a python launcher that detects your installed game (both Ubisoft and Steam work) and launches a private server and redirects the the traffic that Ubisoft Connect and STEEP send to it. This requires setting up hosts file entries (or DNS server if you have one) and installing a certificate on windows. The launcher does both automatically. You can either play alone, host the server for someone else or join someone elses server (currently only in the same LAN is supported).
You can create multiple accounts in the launcher and log in with them in Ubisoft Connect (everything is stored locally). This allows you to play with multiple players or just have multiple saves for yourself. All accounts on the server automatically show up as friends.
Some stuff like achievements or medals requires data scraped/recorded from Ubisoft server. I legally can not distribute that data. Which is why it currently requires loading a "game data pack" .zip file in the launcher to have these things. I will later make a tool where you can record that data and generate the data pack yourself.
It's currently a work in progress and not very polished, but I will improve it going forward. I will later also make this available as a docker image with a web based admin panel so that it can be hosted on a VPS or something and be joined by other people across the internet.
If you have any questions feel free to post them here. Also if you find any problems you can open an issue in the repo.
TL;DR: You can host a private STEEP server that has most functionality of the normal steep server but fully offline!
Source: r/Steep · by /u/SomeRandomNiko