A self-hosted web UI for Claude Code

Manta is a web UI for Claude Code that runs on your own box in real tmux. The same transcript, the same live tool output, the same approvals, in any browser on any device, with the same session on every one.

https://a3f9…b21c.boxes.mantaui.com

Ethernal

feat/auth

refactor/db!

main

Marketing

hero-copy

Infra

deploy

ethernal / feat/auth · box-fra-1

You

add a device-code pairing flow to the auth module

Manta

Reading the current auth module before I change anything.

› read src/server/auth.mjs

› edit src/server/auth.mjs +38 −4

$ npm test ✓ 41 passed · 2.1s

What is on the page

The full client, in a browser tab

Everything you can do at the desktop is here, because the browser client is the same React app served from the box.

✓Full chat transcript. Read every turn the agent has produced, scroll back through the whole session, jump to any tool call.
✓Live tool output. Bash stdout streams at roughly four hertz, with the same context bar you see on desktop.
✓Permission cards. Approve, deny, or write a clarification. The same cards, the same buttons.
✓Voice dictation. Hold the mic, dictate a reply. The same command classifier picks dictation from a question.
✓File upload and screenshots. Drag in an image or a log, the agent gets it as a file path.
✓A real tmux terminal. Switch from chat to terminal in the same window, attach to the same session the chat talks to.

What is on the box

The same box, real tmux underneath

A web UI is only useful if the work survives the tab. Here it does, because the agent lives on your hardware and the browser is a client.

✓Real tmux sessions. The server owns tmux. Close the browser, the agent keeps running, and you can SSH in alongside it and attach to the same window.
✓A worktree per session. New sessions in a git repo branch their own sibling worktree, so several agents work in parallel without standing on each other.
✓A system service. The server runs as a systemd user unit, so a reboot does not kill it. There is nothing to keep alive by hand.
✓Schedules, webhooks and secrets. The agent can put work on a timer, wake up when CI finishes, and read secrets by file path without the value ever appearing in the transcript.
✓Peer sessions. Two agents in the same workspace can see each other, so one can warn another before touching a file it is editing.

How the box reaches you

You do not pick the transport

The installer checks whether Tailscale is already running on the box. If it is, your devices connect over your tailnet and nothing is published to the public internet. If it is not, the box gets its own hostname and a Let's Encrypt certificate.

✓Tailnet when Tailscale is already up. Devices reach the box at a tailnet IP over plain HTTP. Caddy, public DNS and Let's Encrypt are skipped entirely.
✓A per-box hostname otherwise. The installer registers <your-box>.boxes.mantaui.com, provisions the certificate, and reloads Caddy.
✓Pair once per device. Each browser pairs with a six-digit code the box prints. The token is stored locally, sent on every request, and rotated by signing out.
✓Forceable either way. Set MANTA_INGRESS=public or MANTA_INGRESS=tailnet at install time if you want a specific path regardless of what is detected.

FAQ

Questions about the web UI

Four questions, answered in full.

Does the web UI work in every browser?

Yes. The browser client is a standard React app served by the box. Chrome, Safari, Firefox and Edge all work. Mobile browsers on iOS and other phones work too. There is no extension to install.

Do I need to expose the box to the internet?

No. The installer detects whether Tailscale is already running and chooses a tailnet path when it can. Nothing is published to the internet in that case. If you do not run Tailscale, the installer provisions a hostname and a Let's Encrypt certificate for you, and that is the only thing that is public.

How is this different from opening Claude Code's local dev server?

Claude Code's local dev server runs on your laptop and dies when the laptop closes. Manta's web UI is served from a server that runs on a box you own, as a system service, and the agent lives in a real tmux session there. The web UI is a client. Close every browser tab and the work continues, because the agent never lived in the tab.

Does the agent keep running if I close the browser?

Yes. The browser is a client to the box, not the place where the agent runs. Close the tab, shut the laptop, lose the connection. When you open a browser again and pair the device, the same session is there with the full history. The remote page describes the same property from the server end.

Put it on your own box

Free, open source, MIT. Runs on a Linux VPS or a Mac you already own.

$ curl -fsSL https://mantaui.com/install.sh | bash

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