Compared

Murmell vs Codex cloud

Codex cloud takes a task off your hands and works on it somewhere else. Murmell keeps the Codex CLI in front of you, in a window, on a machine we run, in the same directory as every other agent on the canvas.

The real difference

The two products are not aimed at the same moment. OpenAI describes Codex cloud as a way to “run tasks in isolated cloud environments, work in parallel, and start work from the web, GitHub, Linear, or Slack”, with dedicated environments for the long ones and a summary and diff at the end. Isolation is the design, and the diff is the handoff.

Murmell has no handoff, because there is nothing to hand back. The agents are already in the working tree. Codex claims the paths it is about to touch, the board keeps one holder per path and refuses everyone else until it is released, and Claude Code waits its turn on the same files. That rule is enforced by the server, not suggested to the model.

And Murmell is not the agent. It runs the CLIs. Switching from Codex to another agent leaves the directory, the reservations and the history where they are, because those belong to the canvas rather than to whichever CLI is attached to it.

Where Codex cloud wins

The model and the reach of it. Codex is on the web, in a desktop app, in your editor, in the terminal and inside ChatGPT, all on one account, and you configure the dependencies and setup steps a repository needs once. Work can be started from Slack or Linear without anybody opening a browser tab that looks like a desk.

If what you want is a task delegated and forgotten until it is reviewable, Codex cloud is already good at that and Murmell does not try to be.

Which to pick

Pick Codex cloud when one agent can finish the job alone and the diff is all you need to see.

Pick Murmell when you want more than one agent on the same files at once, when you want to read the terminal instead of the summary, or when someone else should be watching. The machine that executes agent code holds no database and no decryption key, so an agent that gets out of its box finds nothing to take. See what the canvas is.