mesimon

mesimon.dev

mesimon (Hebrew משימון, "the task instrument" — pronounced me-si-MON) is a terminal kanban board that runs your coding agents. Like Kubernetes is to containers, mesimon is to Claude Code and Codex.

Your agent is the real Claude Code or Codex, in its own terminal: step into it and you have the same prompt, the same slash commands and the same permission dialogs, and mesimon never sits between you and it.

_{Start an agent with Shift+Enter on the board. When its card lights, open the ticket and answer with Shift+Enter there, then merge its branch with m. Recorded with a scripted stand-in agent so the take is reproducible; assets/demo/ re-records it.}

Alpha. It works and it is used every day, and it will change under you. Each version's changes are in the CHANGELOG.

What it does

• Start an agent on a ticket with one key. Your ticket's title and description are its first prompt. Claude Code and Codex both work.
• Each agent can work in its own worktree, on its own branch, so several agents can change the same repo at once without touching each other's files.
• The card lights when the agent needs you. The board stays quiet while agents work, and a card moves to REVIEW on its own when its agent is done. It turns the one bright colour on the screen only when its agent asks you a question or waits on a permission.
• Review and merge with one key. v shows the branch's diff and m merges it, fast-forward only.
• Agents keep running when you close the board. A background process holds every session, and the next time you open the board everything is where you left it. Idle agents can sleep and wake into the same conversation.

Install

curl -fsSL https://mesimon.dev/install.sh | sh

Or with Homebrew:

brew install amitozalvo/tap/mesimon

Then run mesimon doctor. It checks your setup and prints fixes, and changes nothing.

You need macOS on Apple Silicon or Linux (x86_64 or aarch64, WSL2 included), git, and Claude Code or Codex, signed in. On Linux you also need tmux 3.3 or newer; on macOS mesimon brings its own. Requirements in detail covers the rest, and Updating says how new versions arrive.

First run

1. cd into a git repository and run mesimon.
2. Press o and type a task as the title, for example Add a --version flag.
3. Press shift+tab so the line under the title reads ⎇ worktree. The agent gets its own branch.
4. Press shift+enter. The ticket is saved, an agent starts on it, and its card spins while it works.
5. When the agent is done, its card moves to REVIEW. Press space on it to read what the agent said, then m twice to merge its branch.

If a card lights before then, its agent is asking you something. Press shift+enter on the card to answer it, or enter to go into the agent's own terminal; ctrl-] brings you back.

shift+enter needs a terminal that reports it, such as iTerm2, Ghostty, kitty or WezTerm. If ? does not list it, press enter in step 4 to save the ticket, then c to start its agent, and type the task into it.

? lists every key on the screen you are on. Closing the board does not stop your agents: Stopping everything says how to.

Tour

Your agent, your way. enter on a ticket with a working agent takes you into the agent itself: Claude Code or Codex, exactly as you know it.

_{enter steps into the agent's own terminal, where you type to it as you always do, and ctrl-] steps back out while it keeps working.}

The ticket page. tab on a card writes its description, and ctrl-k lists the links in its notes.

_{tab adds two lines to the brief, enter opens the page with the note its agent left, and ctrl-k opens one of that note's links.}

Search. / finds any ticket by a few letters of its title, key, column or tag.

_{Three letters narrow fifteen tickets to one, and enter scrolls the board to its card.}

The crown. ctrl-o on a card lets its agent file, move, tag and start the other tickets.

_{The crowned agent runs the board, and you keep the crown: ctrl-o on its card takes it back. More on the crown.}

Three promises

1. A strict write allowlist. mesimon writes to a short list of paths, every one named, and nowhere else: never your shell rc, your git config, your agent configuration or your tmux config.
2. No config mutation. mesimon doctor prints fixes for you to apply; it never applies one itself.
3. Zero prompt injection. mesimon adds, removes and reorders no token of your conversation. The board tools it gives its agents, and a brief you can switch on, are shown in full.

The promises in full, with every path mesimon writes. If you find mesimon breaking one, report it.

Learn more

• Using mesimon: the board, settings, keyboard layouts, pictures in notes, what your agents can see, updating and stopping everything.
• What is useful to report, and how to report a security issue.
• All the docs, including the design record and the architecture.

License

Apache-2.0. See LICENSE, NOTICE and TRADEMARK.md.