Crate tmux_companion 

tmux-companion: one daemon that draws the tmux status bar, and the tools around a tmux server that a plugin manager used to provide.

Most people want the binary:

cargo install --locked tmux-companion
tmux-companion doctor

and the manual, man tmux-companion, or the README for what it does.

The library

The same crate is a library, for a program that wants a part of what the binary does without running the binary for it. Three parts are meant to be used from outside, and the documentation shows only those:

• Asking the daemon. daemon::Daemon sends one request to a running tmux-companion server and returns its answer, with the request and response types and each command’s arguments in proto. It’s blocking, needs no async runtime, and never starts or replaces a daemon.
• Parsing and drawing. segments::git parses git status --porcelain=v2 --branch into segments::git::GitStatus and renders it as a segment; tmux::format builds tmux style strings and turns them into ANSI for a terminal; segments::network is the arithmetic behind a transfer rate; keyroute::spell translates key names from nvim, fzf, zsh, nano and Claude Code into tmux’s spelling. None of these touch tmux or a socket.
• Session snapshots. sessions::Snapshot is a whole tmux server as data: sessions::capture builds one from tmux’s own listings, sessions::render and sessions::parse write and read the file format, sessions::store keeps generations of them, sessions::portable moves one between machines, and sessions::import reads what tmux-resurrect saved.

use tmux_companion::segments::git::GitStatus;

let porcelain = "\
# branch.oid 1f2e3d4c5b6a
# branch.head main
# branch.upstream origin/main
# branch.ab +2 -0
1 .M N... 100644 100644 100644 aaaa bbbb src/lib.rs
? notes.txt
";
let status = GitStatus::parse_porcelain_v2(porcelain);
assert_eq!(status.branch, "main");
assert_eq!(status.ahead, 2);
assert_eq!(status.unstaged.modified, 1);
assert_eq!(status.untracked, 1);

Stability

The parts above follow semver: before 1.0 a breaking change to them bumps the minor version and has a line in the changelog. Everything else in the crate is the binary’s own code. It’s public so the integration tests can link against it, it’s hidden from these docs and it changes whenever the binary needs it to, in any release.

The library pulls in everything the binary uses, tokio and ratatui included; there are no feature flags to trim it yet.

Modules

daemon

Asking a running tmux-companion daemon for a segment, from another program.

keyroute

keys that tmux and the apps in its panes both want: what each layer binds, and where they collide

proto

The daemon’s protocol: one JSON Request line in, one JSON Response line out, and one arguments struct per command.

segments

One module per thing the status bar can draw.

sessions

Snapshots of the whole tmux server, and the generations they are kept in.

tmux

Everything that knows about tmux’s own formatting language.