Changelog

Every user-visible change, release by release. The format follows Keep a Changelog and versions follow Semantic Versioning; what counts as a breaking change is in Versioning. Release files are on GitHub Releases.

Unreleased

0.1.5 - 2026-10-21 Latest

Fixed

• C-c, C-\ and C-z typed at a job in a shell with job control (zsh, bash -i) run through zeropty-tty went to the shell, not the job: sleep 30 could not be stopped. A job leads its own process group, and the shell's tcsetpgrp was swallowed by the shim. The shim now reports it, and zeropty signals that group as a tty does its foreground group, so C-z and fg work too, pipelines included. Only a process group with a member under the session's program is taken. A shell started before the upgrade keeps the old shim: start it again.

0.1.4 - 2026-10-21

Fixed

• zeropty-tty: a passphrase typed at ssh, ssh-keygen, ssh-add or any program using readpassphrase or getpass was echoed onto the session's screen, and so stayed in capture-pane output and the scrollback. libc turns echo off there with its own internal calls, which the shim did not reach; the shim now handles these two functions itself on the session's terminal. This covers a program the shim is in, such as zeropty-tty ssh-keygen; /usr/bin programs typed at a shell in the session still run without the shim. Outside a session nothing changes.

0.1.3 - 2026-10-21

Added

• Each release now carries a prebuilt macOS archive, zeropty-<version>-darwin-universal.tar.gz (Apple silicon and Intel, macOS 11 or later), and SHA256SUMS, so zeropty installs without Rust: download, shasum -a 256 -c SHA256SUMS, unpack, and run from the folder. It holds zeropty, shim.dylib, zeropty-tty, claude-zeropty and the licenses, signed ad hoc. The embedding libraries and the bash builtin still come from ./build.sh (README).

0.1.2 - 2026-10-20

Fixed

• zeropty-tty: /dev/tty opened for reading and writing (fzf with its stdin piped in) could read keys but every write failed with EBADF, so fzf drew no list and took no pick. A session's terminal is now one socket, as a PTY is one file: stdin, stdout and stderr are that socket (stdin was a pipe), and /dev/tty in any mode is it. C-d still ends input for good, and output keeps flowing after it. As on a PTY, O_NONBLOCK set on one of stdin, stdout and stderr is now set on all three. Sessions started by an older server and kept by restart-server keep their input pipe; sessions started by this version should not be handed back to 0.1.1 or earlier (C-d would not reach them).

0.1.1 - 2026-10-20

Fixed

• zeropty-tty: the shim treated any program's fds 0-2 as a terminal, so a program whose stdout was piped or redirected got \e]zeropty-tty;N\a mode signals mixed into that output, a program reading /dev/null as stdin failed (kqueue EINVAL), and children inherited the effect. Now only the session's own pipe and socket count, named by the server in the new ZEROPTY_TTY_ID variable, and mode signals go only to the session's output.
• zeropty-tty: the signed copy took the name of the link's target (claude ran as claude.exe), so ps and pgrep claude did not find it. A program, copied or not, now runs under the name it was run by.
• display-message with -t naming a session that does not exist now prints the format with the session's variables empty and exits 0, as tmux does, instead of failing with exit 1. To test whether a session exists, use has-session. Every other command still fails with exit 1, as in tmux.
• A missing -t target is now reported in tmux's words. Without a :, a bare name gives can't find pane: x (capture-pane, send-keys, pipe-pane, paste-buffer, resize-pane) or can't find window: x (resize-window), an id gives the session, window or pane error for $, @ or %, and x.0 gives can't find window: x; set-environment gives no such session: and the target as given. Exit codes are unchanged (1).

0.1.0 - 2026-10-20

The first public version: a session engine for programs that drive many terminal programs (coding agents, scripts, test harnesses), which accepts tmux's command format without a PTY. macOS only. Tagged v0.1.0 on the first public commit, c612089.

Known limitations: macOS only (kqueue, the DYLD shim). One program per session, so there are no windows, panes, status line, copy mode, key bindings or configuration file. wait-pane is not available as an embedded function call, only over the socket (including an embedded listen). Programs protected by SIP or signed with the hardened runtime cannot load the shim, so zeropty-tty runs a re-signed copy instead, and setuid or entitlement programs (top, ps) do not work. End of file with C-d closes the session's input (a pipe has no one-time EOF). Before 1.0, a MINOR release may break the interfaces in docs/VERSIONING.md.

Added

• Server and CLI (zeropty), with the same arguments as tmux: new-session, has-session, kill-session, list-sessions, kill-server, send-keys (key names compared byte for byte with tmux 3), capture-pane (-p -e -J -N -S -E -b -q), load-buffer, paste-buffer, display-message, pipe-pane, rename-session, resize-window/resize-pane, set-environment -g/show-environment -g, attach-session (-r read-only), -V, and 25 tmux format variables. Unknown flags are errors. The first new-session starts the server.
• Commands tmux does not have: wait-pane (waits for text or for quiet without polling), grep-panes (searches the screens of all sessions), pull-sessions/push-sessions (moves running sessions to another process without touching the programs), restart-server (upgrades the server without ending sessions).
• No PTY: a session's program talks to pipes, and the engine emulates the line discipline (Enter, the C-c signal, line editing, echo, C-d). For programs that need a terminal (claude, vim, less, python), shim.dylib, claude-zeropty and zeropty-tty answer isatty, tcgetattr, the window size and /dev/tty.
• Screen emulator: 6 bytes per cell, compared with the vt100 crate (0.16) on recorded claude sessions and random input. Quiet screens are folded away and later compressed with zstd.
• Socket protocol: one JSON line per request and per reply on ~/.zeropty/mux.sock (ZEROPTY_SOCK), an optional raw reply format, and attach frames.
• Embedding: the C ABI (libzeropty_c.dylib, zeropty.h: zeropty_open, zeropty_command, zeropty_listen, and zeropty_open_polled/zeropty_fd/zeropty_timeout_ms/zeropty_process for polled use) and the Node module (zeropty.node, client/embedded.mjs) run the engine inside your process. listen serves the same socket protocol from the host process.
• Clients: client/zeropty.mjs (Node, keeps one connection open), and a zsh function (shell/zeropty.zsh) and a bash builtin (shell/zeropty_bash.c) that talk to the socket without starting a process.
• Environment variables ZEROPTY_SOCK, ZEROPTY_HISTORY, ZEROPTY_COALESCE_MS, ZEROPTY_FREEZE_MS, ZEROPTY_COLD, ZEROPTY_COLD_DIR, ZEROPTY_RECORD (docs/USAGE.md).
• Benchmarks measured interleaved with tmux 3.7c on one Mac mini M1 (docs/BENCHMARKS.md): 11 of the 14 measured items are at 10x or better, and 3 are not there yet (memory with 400 idle sessions on the standalone server at 6.2x, and send-keys against tmux control mode at 8~10x embedded and 2.2~2.8x over the socket). The reasons are in that document.
• A plugin system (Plugin API): plugins receive session create, exit, rename and output events and add new commands. The Rust Plugin trait (API_VERSION 1), plugin-attach over the socket (any language, out of process), C callbacks with zeropty_add_plugin, dylib plugins with zeropty plugin-run/zeropty_load_plugin, an opt-in autostart directory ZEROPTY_PLUGIN_DIR, and a status check with list-plugins. With no plugins there is no cost, and a plugin that panics, hangs or is slow cannot hold up the engine.
• Command calls that do not wait: C zeropty_command_start, zeropty_call_poll, zeropty_call_due_ms, zeropty_call_free, and Node Engine.commandStart.
• zeropty --version: the same output as zeropty -V (zeropty 0.1.0). The zsh function, the bash builtin and client/zeropty.mjs also answer it by running the program, as they do for -V.
• The format variable #{version}: the version of the running server (or embedded engine). A display-message -p that uses only this variable works without a session (zeropty display -p '#{version}').
• C ABI: ZEROPTY_VERSION_MAJOR, _MINOR, _PATCH, _PRERELEASE, _IS_PRERELEASE, _STRING and _NUMBER in zeropty.h, and zeropty_version(), which returns the version of the linked library. ZEROPTY_VERSION_NUMBER does not include the prerelease, so 0.2.0-rc.1 and 0.2.0 have the same value; tell them apart with ZEROPTY_VERSION_IS_PRERELEASE.
• Node: version() in zeropty.node and client/embedded.mjs, and VERSION in client/zeropty.mjs and client/embedded.mjs.
• The versioning policy docs/VERSIONING.md: the compatibility surface whose changes count as breaking (the CLI's arguments, output and exit codes, the socket protocol, the session record, the C ABI, the Node API, environment variables, dist/ names) and the MSRV (Rust 1.88). Before 1.0, a MINOR release may break this surface, and such changes are announced as **BREAKING** entries.
• zeropty --help (-h, help) prints the list of commands and options, and zeropty help <command> prints that command's usage and a link to its documentation. It answers without a server.
• Documentation: a reworked Korean README, a documentation index (docs/README.md), a FAQ, runnable examples (examples/), and rustdoc with examples for every public Rust item.

Fixed

• The CLI no longer panics when the reader closes the pipe early (zeropty capture-pane -p ... | head -1).