Deploy and Host T3 Code on Railway

T3 Code is the open-source "agent harness control surface": a server that runs coding agents (Claude Code, Codex, OpenCode and more) on a machine, and web, desktop and mobile apps that drive them from anywhere. This template makes that machine a Railway service: a cloud agent box with Claude Code, Codex and OpenCode preinstalled, so your agents keep working with the laptop closed and you check in from your phone.

About Hosting - Setup

Add this template
Once the application is deployed, copy T3_SETUP_PASSWORD from the service's Variables tab
Open the public link from railway (click the instance, then Settings, and it's under Networking). Until a browser is paired, the link opens the /railway-pair page, which also explains where to find the password
Enter that password, then click Pair this browser. For your phone, scan the QR code in the T3 Code app (Settings → Environments → Add). Reload the page for a new link for each device

Agent configs

Because of it running in a container the agents are instructed to install tools in a way that persists. The instructions are at default global agent.md - placed at the top of the global instructions for Claude Code, Codex, OpenCode, Antigravity/Gemini, Pi and fx. Your own text in those files, outside the marked block, is kept.

Common Use Cases

Going to work and then closing your laptop
Using your phone to code
It has browser preinstalled so that the agent can access and check itself even when you close the lid of your laptop

Dependencies for T3 Code Hosting

You will need to have an ai subscription that works with one of the providers supported with T3 code. Chatgpt or claude for example. OpenCode's free models work without one.

Why Deploy T3 Code on Railway?

Railway is a singular platform to deploy your infrastructure stack. Railway will host your infrastructure so you don't have to deal with configuration, while allowing you to vertically and horizontally scale it.

By deploying T3 Code on Railway, you are one step closer to supporting a complete full-stack application with minimal burden. Host your servers, databases, AI agents, and more on Railway.

It's a one click setup for an ai agent where you own the data.

Remote Docker

Railway can't run a Docker daemon, but the image has the docker CLI (with compose and buildx) and can use a daemon on another machine over SSH. Agents then use docker and docker compose as usual. This is required for local supabase for instance. For the setup instructions visit

https://github.com/tpkowastaken/railway-t3-code

Disclaimer

This is not affiliated with Theo. You are welcomed to fork, expand and contribute. Railway doesn't support docker in docker setups.