l0ng-ai 422ac027d8 feat(daemon): upgrade the daemon in place instead of killing every shell
Picking up a new build meant stopping the daemon, and stopping the daemon
means every pane dies: the pty master is a descriptor this process holds,
so when the process goes the slave side raises SIGHUP and takes the shell,
the agent and the half-finished command with it. That is why the update
path leaves the old daemon serving and Settings has to offer the restart
as a thing you schedule for a quiet moment.

`execve` does not have that problem. It replaces the image and keeps the
process: same pid, same children, same descriptors, same file locks. The
daemon now rewrites itself that way on `ClientMsg::Handoff` — it writes
what it knows about each pane into a blob, clears FD_CLOEXEC on the pty
masters, the blob and the singleton lock, and execs the new binary, which
picks the panes back up on the other side.

- **the seat travels on the command line, not in the blob.** The lock is
  still held by this process, so the new image must adopt the descriptor
  rather than ask for the lock again — asking would be refused by its own
  lock and it would stand down in favour of itself. A daemon that loses
  its panes is a bad afternoon; a daemon that exits leaves the machine
  with nothing serving, so that one fact has to survive an unreadable blob.
- **the blob is unlinked before it is written.** It holds every pane's
  ring, which is the output `scrollback` makes people opt into storing;
  a handoff must not be a back door for writing it to disk.
- **the exec is the last step.** Everything is staged first, so any
  failure before it costs a log line and the daemon carries on serving —
  which is what lets callers treat a failed handoff as "fall back to a
  restart" without having lost anything on the way.

Native SSH panes cannot cross — their session is cipher state in memory,
not a descriptor — so they are hung up first and the far end sees a clean
close. Windows has neither execve nor a transferable ConPTY handle, so it
keeps the stop/start path; the dialogs there still promise what they
always did, and the new copy is shown only where it is true.

Also retries flock on EINTR: a signal landing mid-call said nothing about
the lock, but was reported as "could not be evaluated", which starts a
second daemon beside the first — the split machine singleton exists to
prevent.

The end-to-end test sets a variable in the shell, hands over, and reads it
back. Nothing but the original process can answer that, and the daemon's
instance id changing while its pid does not is what says an exec really
happened.
2026-08-09 23:03:40 +08:00

tty7

tty7

A terminal workbench: persistent sessions, remote work, agents.

Pure Rust · GPU rendering on Zed's gpui · VT core from Alacritty


CI Version License Discord

English · 简体中文

Why

  • Performance — ~2× the throughput of Alacritty, Ghostty, or Kitty (benchmarks)
  • Persistent sessions — quit or reboot; your shells and supported agent sessions keep running, no tmux
  • Editor-grade input — suggestions, completion, highlighting, history search
  • Remote development — files, repos, panes, and git data stay on the remote machine
  • Native SSH — profiles, SFTP, port forwarding, and jump hosts
  • Agent-aware — Claude Code, Codex & co.: status, notifications, git context
  • CLI + Skills — agents create panes, run commands, and inspect output

Install

Native builds for each platform on Releases:

macOS …-macos-arm64.dmg · …-x86_64.dmg drag into Applications
Windows …-setup.exe · portable ….zip
Linux …-x86_64.AppImage chmod +x and run — X11/Wayland libraries bundled

What's inside

Editor-grade input ghost suggestions from history · explained tab completion · syntax highlighting · multi-line editing · click places the caret · ⌃ R fuzzy history
Window tabs & splits · ⌘ P palette · ⌘ F scrollback search · nine themes · IME
Agent-aware per-pane detection (18 CLIs): status dot · notifications · branch + diff · resume after reboot · tray icon when input is needed
Remote workspaces remote files, repos, changes, diffs, worktrees, tabs, and panes · reconnect from any client and continue where you left off
CLI + Skills bundled tty7 CLI · agent skill · pane/workspace control · real PTY commands · output, process, port, and agent status
SSH native russh stack: profiles with keychain secrets · SFTP panel · port forwarding · jump hosts · one-time, unprivileged tty7-server install

Terminal and keybinding reference: docs/features.md. The agent-facing CLI interface is documented in skills/tty7/SKILL.md.

Install the skill with:

npx skills add l0ng-ai/tty7

Benchmarks

Same machine, same day, same 155×40 grid — Apple M1 Pro, macOS 26.3.1, five-run averages (2026-07-04):

tty7 Alacritty Ghostty Kitty
Plaintext I/O — 11 MB cat (lower = better) 95 ms 239 ms 179 ms 185 ms
DOOM-fire frame rate (higher = better) 888 fps 485 fps 552 fps 617 fps
Cold-launch memory 116 MB¹ 105 MB 128 MB 130 MB

¹ GUI 105 MB + the persistent server 11 MB.

Methodology and one-command reproduction: scripts/bench/.


S
Description
A terminal workbench in pure Rust: shells, persistent sessions, SSH, coding agents. GPU-rendered on Zed's gpui, VT core from Alacritty.
Readme Apache-2.0
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