Explained

What is Murmell?

Murmell is a canvas in your browser where you open real coding agents, Claude Code and Codex, inside windows that hold real terminals. The agents run on a cloud machine rather than on your laptop, and several of them work in one project directory. Each agent reserves a file before it writes, so the second one to reach a file is refused instead of quietly overwriting the first.

Send the link to somebody and they are in the canvas with you, watching the same terminals scroll, with their name on their cursor.

What you look at

A light dotted canvas with windows on it, drawn the way macOS draws a window. Each window is one agent’s terminal, showing the output of the actual CLI on our machine in the characters it printed. Windows sit next to each other, so five agents are five windows on one screen and you read all of them at once.

The canvas on the home page is the same object, drawn.

One directory, and a board that says who holds what

Give three agents the same checkout with no rules and they overwrite each other inside a minute. Last write wins, silently, and nobody finds out until a test breaks for no reason anybody can see.

So an agent claims the paths it is about to touch before it touches them. The board records one holder per path and refuses everyone else until the holder releases it. That refusal comes from our server, so it is not an instruction in a prompt that a model can decide to skip. A write that collides anyway is snapshotted before it lands.

Nobody writes without asking first.

Multiple AI agents on one repo goes through the board properly, including what we measured when we watched two agents use it.

The people in the room

A read link is free and there is no limit on how many you hand out. Edit links are capped by your plan. Whoever opens a link sees the windows where they are and the terminal output as it arrives, and sees the other cursors move with a name on each one.

Closing your tab does not kill the agents. They belong to the canvas, so the work carries on without you and is still running when you come back. Multiplayer coding with AI agents covers what two people on one canvas can each do.

Where the code goes

Every project gets a private repository, and the work is pushed to it as the project goes. A machine about to be torn down pushes one last time before it goes, so the disposable part is the machine and never the code.

The machine that executes agent code holds no database and no decryption key. An agent that escapes finds a project directory and nothing to steal. A cloud sandbox for AI agents says which secrets live where.

Where the name comes from

Murmell is from murmuration, the shape a flock makes when thousands of birds move as one. The same word means a low sound, a murmur, and that is the logo: a single wave.

Straight answers