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Fed.run – online collaborative Rust IDE and Markdown editor

Fed.run – online collaborative Rust IDE and Markdown editor

by oinoom·May 23, 2026·2 points·0 comments

AI Analysis

MidCozyShip It

Yjs-powered Rust editor but Replit and GitHub Codespaces already do this better.

Strengths
  • Rooms deallocate automatically after idle timeout — no persistent storage overhead.
  • rust-analyzer diagnostics and cargo test support work inside the browser sandbox.
  • Progressive web app design enables home screen installation on mobile devices.
Weaknesses
  • Not open source yet — hard to verify security claims about sandboxing.
  • No mention of conflict resolution edge cases or offline sync capabilities.
Target Audience

Rust developers, pair programmers, mobile coders

Similar To

Replit · GitHub Codespaces · StackBlitz

Post Description

I’ve been fascinated by CRDTs for the last while and wanted to make something practical with them. I also like to code on my phone but was kind of disappointed with what I’ve tried. So I made fed.run. It’s a progressive web app (so you can add it to your home screen). The frontend uses CodeMirror 6 for the text editor. It also uses Yjs and Hocuspocus for the collaborative aspect (less hands-on than I wanted for CRDTs but, after working on this myself and running into struggles with Loro, I decided to use a higher-level approach). The backend is written in Rust and is responsible for room lifetime management. Every room is ephemeral and the code execution is sandboxed. There is no code or execution output stored outside of the ephemeral room, and the room’s resources deallocate shortly after the last person in the room leaves or goes idle for long enough. There is also rust analyzer diagnostic and code completion support. You can also run cargo tests.

I haven’t open sourced this yet but I’m thinking of doing that soon. Honestly would love to make a little hosted interview helper product out of this and perhaps open source the self-hosted solution.

Feedback and ideas appreciated!

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