A pane costs about three descriptors — the pty master and the pipes behind it
— and the daemon took whatever soft limit its launcher happened to have. On
the historic macOS default of 256 that is a ceiling around eighty panes,
against a `MAX_PANES` of 16,384, and nothing in the failure said so:
tty7: spawning a shell: daemon refused Spawn: dup of fd 93 failed
That sentence does not contain the word "file". Measured with an inherited
soft limit of 96, the daemon stopped at 26 extra tabs.
Two halves. The soft limit is now taken up to the hard limit at startup, which
is the ordinary thing a long-lived server does, needs no privilege, and leaves
an administrator who lowered the *hard* limit in charge of the ceiling. Capped
at `OPEN_MAX` because macOS refuses `RLIM_INFINITY` outright and a refused
request would leave the low limit in place, which is the one outcome worth
avoiding. Same measurement afterwards: past 45 tabs and still going.
And when the hard limit genuinely is the ceiling, the refusal says what it is
and what to do, keeping the original in parentheses for whoever needs it. The
re-wording sits where the spawn handler turns the error into a reply, not at
`openpty`: several calls along that path can hit the limit, and libc's "Too
many open files" and portable-pty's "dup of fd N failed" both arrive there.
Matched on the text because portable-pty hands back a message, not a code —
so the test covers both spellings and, more importantly, that a missing
program and a permission error are left exactly as they were.
Verified against a live daemon in both configurations: a low soft limit is
raised past, and a low hard limit produces the new sentence with the daemon
still serving afterwards.
tty7
A terminal workbench: persistent sessions, remote work, agents.
Pure Rust · GPU rendering on Zed's gpui · VT core from Alacritty
English · 简体中文
Why
A background server owns your shells and panes — not the window. Everything below follows from that.
- 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
- Agent-aware — Claude Code, Codex & co.: status, notifications, and git context for every repo at once
- Scriptable by agents — one agent opens a pane for another, hands off a task, waits, and reads the result, with or without the GUI running
- Editor-grade input — suggestions, completion, highlighting, history search, with no plugin to install
- Remote development — files, repos, panes, and git data stay on the remote machine, over a native SSH stack
- Git beside the terminal — source control, diffs, and worktrees without leaving the window
Install
Native builds for macOS, Windows, and Linux 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
| Agent-aware | per-pane detection (19 CLIs) · status dot · notifications · branch + diff · tray icon when input is needed · resume after reboot · tab sidebar grouped by repository |
| CLI + Skills | bundled tty7 CLI · agent skill · run streams a command and exits with its code · split · send · wait --until free · capture |
| 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 · ⌘ J panel with process tree and listening ports · 13 themes, your own YAML, iTerm2 import · IME |
| Shell integration | injected when a pane starts, nothing to install · prompt marks · working directory · exit codes · command-finished notifications · zsh, bash, fish, nushell, PowerShell, WSL, remote panes |
| Remote workspaces | remote files, repos, changes, diffs, worktrees, tabs, and panes · reconnect from any client and continue where you left off |
| SSH | native russh stack: profiles with keychain secrets · SFTP panel · port forwarding · jump hosts · one-time, unprivileged tty7-server install |
| Git | panel follows the focused pane · stage, commit, amend, branch, push, stash · side-by-side or unified diffs · commit graph with cherry-pick, revert, and reset · a new worktree opens its own tab |
Supported agents
Detection is free: brand avatar, branch + diff, tab title.
Status takes one click under Settings → Agents to install that agent's hook,
and brings the status dot, notifications, the tray icon, tty7 wait, and resume
after a reboot. Fork needs both — the agent's own fork command, and the hook
that tells tty7 which session to fork.
The full support matrix, all nineteen
| Agent | Detected | Status · resume | Fork |
|---|---|---|---|
| Claude Code | ✓ | ✓ | ✓ |
| Codex | ✓ | ✓ | ✓ |
| Grok | ✓ | ✓ | ✓ |
| OpenCode | ✓ | ✓ | ✓ |
| Oh My Pi | ✓ | ✓ | ✓ |
| Droid | ✓ | ✓ | ✓ |
| Qwen Code | ✓ | ✓ | ✓ |
| Goose | ✓ | ✓ | ✓ |
| Gemini | ✓ | ✓ | |
| Copilot | ✓ | ✓ | |
| Kimi Code | ✓ | ✓ | |
| Pi | ✓ | ✓ | |
| Aider | ✓ | ||
| Amp | ✓ | ||
| Cursor | ✓ | ||
| Auggie | ✓ | ||
| Hermes | ✓ | ||
| Vibe | ✓ | ||
| Antigravity | ✓ |
None of them are wrapped or proxied — the agent you start is the agent you get,
in a normal PTY, with its own interface. An agent launched through a wrapper
script can be mapped to one by name with agent_commands in config.json.
Documentation
Full documentation lives in docs/ —
keyboard shortcuts ·
config.json ·
CLI reference. The agent-facing CLI interface is also
documented in skills/tty7/SKILL.md.
Install the skill with:
npx skills add l0ng-ai/tty7 # install
npx skills update tty7 # update later
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/.
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