Your terminal,
in any browser tab.

Q: What do I install?

A small daemon on each Mac or Linux machine you want to reach. It dials out to Merkur, so there is no SSH, no open port and no VPN. Link it once, then open it from any browser.

Q: Which browsers work?

Chrome and Edge 113+, Safari 26.4+ on macOS, iOS and iPadOS, Firefox 141+ on Windows and 145+ on Apple Silicon Macs with macOS 26, and Chrome 121+ on Android. The daemon runs on macOS 13+ and Linux.

Q: Can Merkur see my terminal?

No. The server signs you in, keeps your machine list and issues short-lived session tickets. It is never in the path of a keystroke. Sessions are sealed end to end with ML-KEM-1024 and Noise.

Q: What if my network blocks the direct connection?

Your browser connects straight to your machine over WebTransport. When a network blocks that, a relay carries the session instead. It forwards sealed frames and cannot read them.

Q: Does it work on a phone?

Yes. Merkur adds its own key row above the keyboard: Esc, Ctrl, Alt, Paste, PgUp, PgDn and Tab. Add the site to your home screen and a terminal bell can arrive as a notification.

Q: What does it cost?

It is free during the beta for up to 3 linked machines. Hosted boxes will not count toward the three. There is no paid plan.

Sessions that survive sleep, flaky Wi-Fi and switching devices. Leave Claude Code running at home and pick it up from your phone.

Start free How it works

Free for 3 machines · macOS and Linux

>the ticket tests fail since the refactor. find out why

Read(src/session/ticket.ts)

Read 84 lines

Search(pattern: "expiresAt", path: "src")

Found 3 files

Found it. expiresAt is stored in milliseconds, but isExpired() compares it with seconds, so every ticket reads as expired.

Edit file

src/session/ticket.ts

37export function isExpired(t: Ticket, now = Date.now()) {

38 - return t.expiresAt < now / 1000;

38 + return t.expiresAt < now;

39}

Do you want to make this edit to ticket.ts?

1. Yes

2. Yes, allow all edits during this session (shift+tab)

3. No, and tell Claude what to do differently (esc)

Update(src/session/ticket.ts)

Updated src/session/ticket.ts with 1 addition and 1 removal

38 - return t.expiresAt < now / 1000;

38 + return t.expiresAt < now;

Bash(bun test src/session)

Running…

18 pass 0 fail

Fixed. Tickets compare in milliseconds now, and the session tests pass.

Investigating…Editing…Testing… (esc to interrupt)

? for shortcuts

Runs anything your shell runs

Claude Code
Codex
Neovim
tmux
Git
Docker

Leave it running. Answer from anywhere.

The session lives on your machine. When a program rings the terminal bell, your phone hears it.

01The bell reaches your lock screen.
02Answer with Esc, Ctrl and Tab on hand.
03Pocket it. The work carries on at home.

9:41

Mac.bbrouter Direct · 31ms12.8kB

Update(src/session/ticket.ts)

1 addition, 1 removal

Bash(bun test src/session)

18 pass 0 fail

Fixed. Tickets compare in milliseconds now, and the session tests pass.

? for shortcuts

9:41

Mac.bbrouter Direct · 31ms12.8kB

Found it. isExpired() compares ms with seconds.

Edit file

src/session/ticket.ts

-return t.expiresAt < now / 1000;

+return t.expiresAt < now;

Do you want to make this edit to ticket.ts?

1. Yes

2. Yes, allow all edits

3. No (esc)

EscCtrlAltPastePgUpPgDnTab

qwertyuiop

asdfghjkl

zxcvbnm

123spacereturn

Feels local, even underground.

Push the fader from fibre up to the Underground. Every key lands the moment it's pressed, and output follows one round trip later.Push the fader up. Keys still land straight away.

1mskeypress to glyph on the GPU · p50, measured

Fibre 15 ms · 0.0% loss

Text, not video

Your machine sends terminal cells, never pixels. WebGPU draws them in the tab, crisp at any zoom.
Only what changed

Each update carries just the rows that changed. A full screen is a few KB.
Compressed for your screen

zstd with a dictionary built from your own screen, so an update fits in one packet.
Repaired, not resent

Packets travel in groups with a parity shard. Lose one and it is rebuilt on arrival.

Not just another web terminal.

Screen state, not a byte stream

Your machine sends the rows that changed. Reconnect and you get the latest screen, not a replay.

Or from your own terminal

Run merkur in Ghostty, kitty or iTerm to open the same sessions, images included.

Renders like a native terminal

The grid comes from a patched Alacritty core, not xterm.js. Wide glyphs, box drawing and true colour look exactly as they do locally.

Images in the terminal

Kitty graphics work. Pixels travel apart from text, so a picture never slows your typing.

Merkur Boxes · coming soon

A machine for your agents, with a seat for you.

Hosted Linux boxes that open in the same tab as your own machines. I'll email you when they're ready.

Post-quantum, end to end.

A fresh ML-KEM-1024 exchange for every session. Traffic recorded today stays sealed.

Your browser

Mac.bbrouter

The keys exist only in your browser and on your machine.

post-quantum
ML-KEM-1024
X25519
ChaCha20-Poly1305

Mac.bbrouterSecure Enclave

Your browser verified

A copy of its diskno chip

Your browser refused

The machine's keys are made inside its chip and never leave it. Every proof carries an ML-DSA-87 and a P-256 signature.

hardware-bound
Secure Enclave
TPM 2.0
ML-DSA-87

Sign-in uses OPAQUE, so the server never holds your password. Once the session starts, it is out of the path.

never in the path
OPAQUE
ML-DSA-87 tickets

Also: signed updates that refuse downgrades, and image decoding in a sandbox.

Security model

AGPL-3.0

Open source. Read every line.

The daemon, the relay, the crypto and the renderer live, in one public repo. Audit what runs on your machine, or build it yourself.

View on GitHub $git clone github.com/merkur-sh/merkur

Questions

What do I install?

A small daemon on each Mac or Linux machine you want to reach. It dials out to Merkur, so there is no SSH, no open port and no VPN. Link it once, then open it from any browser.

Which browsers work?

Chrome and Edge 113+, Safari 26.4+ on macOS, iOS and iPadOS, Firefox 141+ on Windows and 145+ on Apple Silicon Macs with macOS 26, and Chrome 121+ on Android. The daemon runs on macOS 13+ and Linux.

Can Merkur see my terminal?

No. The server signs you in, keeps your machine list and issues short-lived session tickets. It is never in the path of a keystroke. Sessions are sealed end to end with ML-KEM-1024 and Noise.

What if my network blocks the direct connection?

Your browser connects straight to your machine over WebTransport. When a network blocks that, a relay carries the session instead. It forwards sealed frames and cannot read them.

Does it work on a phone?

Yes. Merkur adds its own key row above the keyboard: Esc, Ctrl, Alt, Paste, PgUp, PgDn and Tab. Add the site to your home screen and a terminal bell can arrive as a notification.

What does it cost?

It is free during the beta for up to 3 linked machines. Hosted boxes will not count toward the three. There is no paid plan.

Open your first machine.

One command on your Mac or Linux box. Free for three.

Start free $curl -fsSL merkur.sh/install | sh

Your terminal, in any browser tab.