webtmux v0.1.0

webtmux v0.1.0

First tagged release of this fork. Until now every binary reported its version as
dev, because the repository carried no tags for git describe to find — so this
release exists as much to make a binary able to say what it is as to publish one.

0.1.0 rather than 1.0.0 deliberately: this is a personal fork and makes no
compatibility promise yet. 1.x would also collide with gotty's lineage.

What this fork adds over upstream

A browser UI built around watching many tmux windows at once, rather than
attaching to one:

• Stoplights and work alerts — every window reports green (working) / amber
  (prompting you) / red (waiting for work) via the tmux option @wt_working, and
  anything showing that window flashes when it changes while you are looking
  elsewhere. Built for keeping an eye on a fleet of coding agents.
• Four ways to monitor and reach a window — Exposé mosaic, picture-in-picture
  and preview bar, sidebar window tree, and a most-recently-used tab strip.
• Hover previews — pointing at any window paints it full-size in a real
  terminal region, and puts back what you were looking at when you move away.
• Split view — side-by-side live regions, each an independent tmux view backed
  by its own grouped session.
• State persistence — the UI's visual state survives a reload, stored in tmux
  itself.
• webtmux-launch — run webtmux against a remote machine from your laptop.
  It installs webtmux on the target over SSH and supervises the tunnel; the target
  needs only ssh and tmux.

Authority and hardening

Most of the features above were built assuming a trusted browser on a loopback
port. This release closes the gaps that assumption left, because the launcher now
makes remote use ordinary:

• -w (read-only) means watch again. It gated exactly one thing — keystrokes
  reaching the pty — while everything the browser learned to ask for afterwards
  (select/kill/rename a window, switch or kill a session, rewrite the shared UI
  state, write a file on the machine tmux runs on) arrived with no authority check.
  A read-only server handed any authenticated client the whole tmux server plus a
  filesystem write primitive. Every client→server message is now classified once
  and enforced before dispatch; view-only is the set that changes nothing another
  client can observe.
• Saving a pane buffer is confined to declared directories. An absolute path
  was honored as typed and a relative one could climb out with ../. A resolved
  path must now land inside a directory somebody actually named as a destination,
  with symlinks resolved on both sides. A save also never replaces an existing file
  without asking.
• tmux commands no longer guess. Every mutation targets an exact window or
  session, listings put machine-readable fields first so an arbitrary window name
  cannot break parsing, identity reads are keyed by format rather than position,
  and websocket reads and capture fan-out are bounded.
• The UI state protocol converges. Concurrent browsers adopt the server's copy
  per section instead of overwriting each other.

Read-only is still not a sandbox — it is a browser-facing authority boundary. Bind
loopback and tunnel over SSH, as the install steps below do.

Install

Binaries are release assets, one per platform, named webtmux-<os>-<arch>. The
repository is public, so no token and no gh is needed:

curl -fsSL -o webtmux \
  https://github.com/sparant/webtmux/releases/download/v0.1.0/webtmux-linux-amd64
chmod +x webtmux
./webtmux -a 127.0.0.1 -w tmux new-session -A -s main

Bind loopback as above unless you mean otherwise: the default address is 0.0.0.0,
and authentication is HTTP basic auth over plain HTTP.

SHA256SUMS covers every binary in this release:

curl -fsSL -O https://github.com/sparant/webtmux/releases/download/v0.1.0/SHA256SUMS
sha256sum --check --ignore-missing SHA256SUMS

See the README's Installation section for a full fresh-machine walkthrough
(tmux prerequisite, ~/.local/bin, macOS quarantine xattr).

Notes

• Asset names are an interface. webtmux-launch builds its download URLs from
  them, so they will not be renamed. Adding platforms is safe.
• The browser UI still loads xterm.js and Tailwind from a CDN at runtime; removing
  that dependency is planned, not done.
• Built with CGO_ENABLED=0; the binaries are static and embed their assets.