tmux support

No libtmux port requires a tmux newer than 3.3a. The ports, the MCP servers and the workspace builders support tmux 3.3a and newer, except Python and Elixir, which state an earlier floor. A port that enforces its minimum refuses an older daemon before the requested operation has any effect.

Minimum by port¶

• Python (libtmux) and libtmux-mcp: tmux 3.2a.
• tmuxp: tmux 3.2a, the floor of the libtmux release it depends on. Its own README and quickstart say 3.2.
• Elixir: tmux 3.3.
• Every other port, with its MCP server and workspace builder: tmux 3.3a.

The core minimum¶

The minimum for ordinary reads, writes, batches, raw commands, workspace loading and MCP tools is the port’s own, tmux 3.3a for most ports. Releases compare in full, including patch letters, so 3.3 is below a 3.3a minimum and 3.3a is the first supported release. A development build such as next-3.9 ranks below the release it precedes, and a release candidate ranks below its release. A version the library cannot read is refused, not assumed to be new enough.

Libraries judge the daemon that answers on the selected socket, not the tmux executable that sends the command. The two can differ, for example when a newer client binary talks to a server started by an older one. The rules are:

• An existing server is checked by the version it reports. A newer client binary does not authorize an older daemon.
• With no server on the socket, the library validates the executable that would start one.
• A server that restarts on the same socket is checked again before ordinary operations use it.
• Typed methods, raw commands, command batches, workspace loading and MCP tools all pass the same check. A lenient listing call reports the refusal instead of returning an empty list.
• The refusal raises the port’s version error and happens before the command runs, so a refused call leaves no session, window, option or buffer behind.

The Python library does not refuse an older tmux by itself. Its has_minimum_version helper compares the version that the tmux executable reports with 3.2a, and no library operation calls it. The Elixir port declares its floor and tests it, and has no runtime refusal.

Running tmux -V or tmux -h on an older executable still works; see the command reference. Their output does not authorize later operations.

The check assumes tmux’s built-in commands keep their meaning. A command-alias that redefines a built-in command the library uses to identify or guard the daemon is outside this guarantee, as are the contents of user-written aliases and shell programs a library only forwards.