Deploy and Host OpenAI Codex CLI on Railway

Codex CLI is OpenAI's coding agent for the terminal — it reads your repo, writes and edits code, runs commands, and opens pull requests. This template runs the real codex TUI on a persistent Railway box with two ways in: railway ssh from your terminal, or a browser terminal on a public domain — both attached to the same tmux session, with repos, auth and sessions on a volume that survives redeploys.

About Hosting OpenAI Codex CLI

One container runs the actual Codex CLI, not a reimplementation of it. ttyd serves a persistent tmux session on a password-protected Railway domain, and railway ssh --session codex attaches to that very same session — so a dropped connection, a closed tab, or a switch from laptop to phone never loses your place. A /workspace volume keeps repos, config.toml, auth.json and your Codex session history across redeploys, so codex resume still works. git and the GitHub CLI are preinstalled, and the Codex version is pinned so two deploys of the same commit build the same agent. The deploy form asks for no credentials at all — you authenticate inside the box the same way you do locally, with codex login --device-auth on your ChatGPT plan, or by adding an OPENAI_API_KEY variable if you would rather bill at API rates.

Why Deploy Codex CLI on Railway?

The real TUI, not a clone — you type codex and get exactly what you get locally. Codex ships no self-hostable web UI; rather than fake one, this template gives you the genuine terminal, twice.
Your laptop can sleep — the agent keeps working; reattach from the browser or railway ssh and pick up mid-task.
Nothing is lost on disconnect — tmux holds the session, and both doors attach to it.
Sign in from a phone — the browser terminal makes codex login --device-auth work without installing anything, anywhere.
Persistent — repos, auth and codex resume history sit on a volume, so a redeploy never logs you out or loses your working tree.
Secure by default — the browser terminal sits behind HTTP basic auth with a unique password generated for your deploy and shown in your Variables tab; SSH is Railway-authenticated. Codex runs with approval_policy = "on-request", so the agent asks before it acts.

Common Use Cases

A cloud coding-agent workstation reachable from a terminal or a browser tab.
Long-running refactors or migrations that keep going regardless of your local machine.
A shared, reproducible agent environment with a pinned Codex version across repositories.

Dependencies for Codex CLI Hosting

A ChatGPT plan (Plus / Pro / Business / Edu / Enterprise) for codex login --device-auth, or an OPENAI_API_KEY (billed at API rates).
The Railway CLI for terminal access (railway ssh); the browser terminal needs only a browser.

Deployment Dependencies

Codex CLI — OpenAI's open-source coding agent (@openai/codex on npm, version-pinned in the image).
ttyd — serves the terminal over HTTP.
GitHub CLI — bundled so the agent can manage issues and pull requests.

Why This Template?

One click gives you a persistent Codex box you can reach from a terminal or a browser, with a pinned agent version and credentials, repos and session history that outlive every redeploy. Source and docs: github.com/yuting1214/codex-railway.