muster

Muster

A session manager for concurrent Claude Code sessions: a Go daemon (musterd) plus a web dashboard, with interactive terminal panes backed by tmux. One place to see which session is working, which one is waiting on you, and how much context each has left.

Personal tool, macOS only, single user. Not a product. What remains before v1 is in TODO.md.

Install

curl -fsSL https://raw.githubusercontent.com/Zalaras/muster/main/scripts/install.sh | sh

That takes the latest release for your Mac's architecture, verifies it against the release's published SHA-256, and puts musterd in ~/.local/bin. The dashboard is compiled into the binary (//go:embed), so that one file needs nothing beside it.

Piping a script into sh unread is a fair thing to refuse — download it first instead:

curl -fsSL -o install.sh https://raw.githubusercontent.com/Zalaras/muster/main/scripts/install.sh
less install.sh
sh install.sh

Either way, --help lists every option; each has an environment-variable equivalent:

sh install.sh --version v0.9.0          # pin a release instead of taking the latest
sh install.sh --bin-dir /usr/local/bin  # somewhere else on your $PATH

Then confirm it worked — both lines, not just the second:

command -v musterd   # must print the path you just installed to
musterd -version     # prints the musterd version and the Claude Code verified range

If command -v prints some other path, an older musterd earlier in your $PATH (usually /usr/local/bin/musterd) is shadowing the new one and -version is reporting that stale binary. The installer warns when it detects this. Delete the old copy, or re-run with --bin-dir pointing at the directory it lives in.

The binary is unsigned, but curl does not set the com.apple.quarantine xattr, so it runs without a Gatekeeper prompt. A browser download does — clear it with xattr -d com.apple.quarantine musterd.

Verifying a first install yourself

The installer's SHA-256 check guards integrity, not authenticity: checksums.txt comes from the same host as the archive it vouches for. Releases are minisign-signed — a separate matter from the Apple code signing above, and every checksums.txt since v0.12.1 ships a checksums.txt.minisig — but install.sh deliberately does not check it, because a public key it downloaded alongside the payload is no more trustworthy than the payload (ADR). Signature checking begins the moment musterd is on disk, against the key compiled into it — see below.

To check a release yourself first (brew install minisign):

tag=v0.12.2; arch=amd64   # uname -m: x86_64 -> amd64, arm64 -> arm64
base=https://github.com/Zalaras/muster/releases/download/$tag
curl -fsSLO $base/checksums.txt
curl -fsSLO $base/checksums.txt.minisig
curl -fsSLO $base/musterd_${tag#v}_darwin_$arch.tar.gz
curl -fsSLO https://raw.githubusercontent.com/Zalaras/muster/main/internal/selfupdate/minisign.pub

minisign -Vm checksums.txt -p minisign.pub                          # key 7FA9D01D017D739A
grep " musterd_${tag#v}_darwin_$arch.tar.gz\$" checksums.txt | shasum -a 256 -c
tar -xzf musterd_${tag#v}_darwin_$arch.tar.gz -C ~/.local/bin musterd

minisign.pub there is the same key musterd embeds, so Signature and comment signature verified means the release came from the project's own pipeline.

Updating

musterd checks GitHub Releases once a day for a newer version (turn it off with the Check for updates daily box in Settings — off means no request at all). When one exists, the masthead Settings button gains a dot; the dialog's Updates section then offers Update (swaps the binary, then asks you to restart) and Update and restart (swaps and re-execs in place — every Claude session keeps running and is re-adopted; only plain-terminal shells close, and the confirm step names them). From a terminal, musterd -update does the swap without restarting anything. Every download is verified twice: the release's checksums.txt must carry a valid minisign signature against the public key compiled into the binary, and the archive's SHA-256 must match that signed file — nothing is installed otherwise. A musterd installed by Homebrew is updated with brew upgrade musterd once the tap exists, and the dialog says so instead of offering the buttons.

Requirements

• macOS. Muster is single-user, macOS-only tooling — see SPEC.md.
• tmux 3.2 or newer. Every session runs in tmux, on Muster's own dedicated socket, never your default server. musterd checks this at startup and refuses to start if tmux is missing or too old, naming the remedy:

  brew install tmux    # not installed
  brew upgrade tmux    # older than 3.2
  

• Claude Code, verified against 2.1.246–2.1.296. Its auto-updater is deliberately left on — see below.

Claude Code versions

Muster does not disable Claude Code's auto-updater; that would freeze your everyday install. It detects and classifies instead: musterd compares the installed version against the canary-verified range and warns on either side of it — below the floor means "update Claude Code", above the ceiling means Muster hasn't been tested there yet — without ever refusing to start. A green make canary run extends the range automatically. Full rituals: docs/claude-code-versions.md.

Development

git clone https://github.com/Zalaras/muster && cd muster
nvm use && make build        # ./bin/musterd, dashboard embedded

make help      # list targets
make check     # lint + unit tests
make web       # frontend dev server
make e2e       # Playwright suite (needs: npx playwright install chromium)
make canary    # assert the installed Claude Code still emits what Muster needs

Toolchain: Go 1.27.1, Node 24.21.0 (pinned in .nvmrc), Vite 8, TypeScript 7, Playwright 1.63. Claude-Code-specific knowledge is confined to internal/claudecode/.

Issues and contributions

Issues are welcome; pull requests are not accepted at this time — see CONTRIBUTING.md, which also covers what the dashboard's Issue button attaches and what it never sends. Forks are fine; the MIT licence permits it.

Docs

Licence

MIT.