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cordless v0.8: Tab Groups, Custom Launchers & Bring-Your-Own Copilot

Running so many agent sessions they overflow the screen? cordless v0.8 gives them Chrome-style tab groups, lets you define your own launchers (and ships a built-in GitHub Copilot CLI profile), renames tabs, and keeps each session's scrollback across a reboot. Plus a real installer — and the story of a graceful-shutdown bug that only failed on Linux.

ai4goodcliterminalcoding-agentstab-groupsgithub-copilot

TL;DR — cordless is a CLI-first tool that manages your remote terminal / coding-agent sessions and puts them on your phone. v0.8 is about organising the swarm: Chrome-mobile-style tab groups, custom launchers (bring any command as a profile), a built-in GitHub Copilot CLI profile, renameable tabs, and persisted scrollback history so a reopened session after a reboot shows what it was doing. There’s also a proper cordless setup installer. Six features, each on its own branch — designed with GPT-5.6 Sol, built with GitHub Copilot CLI.

cordless v0.8 — tab groups, custom launchers, Copilot

v0.7 taught cordless to tell me which of my eight agent sessions needs me. v0.8 is the next problem: once you’re running that many, they stop fitting on the screen. You need to organise them — like browser tabs, because that was the whole metaphor from day one. So this release is six features that make a big session swarm manageable.

Tab groups

The headline. Sessions can now live in named, colored groups — think “API migration”, “Website”, “Flaky tests” — exactly like Chrome mobile’s tab groups.

In the terminal dashboard, groups render as collapsible headers with a live per-group waiting/session count:

── Sessions (6) ──
▼ API migration          2 waiting · 3 sessions
  ! claude   build pipeline            waiting
  ● codex    api tests                 working
  ○ shell    api ~/src/api             idle
▶ Website                              2 sessions
▼ Ungrouped                            1 session
    ○ copilot scratch                  idle

Press g for the group menu (new / assign / ungroup / collapse / rename / delete), and f to cycle a smart-view filter — All · Attention · Claude · Codex · Copilot · Shell. Those filters are views, not groups; collapse state is per-device. On the phone you get the same idea as a chip strip above the tabs (All · Unread · one chip per group, with counts and color dots) plus rename/move in the details sheet.

The design decision I kept going back and forth on — and where Sol was firm — was manual groups over continuous auto-grouping. Auto-sorting your tabs by directory sounds clever until a session changes cwd and silently jumps groups. So groups are something you choose; deleting one never kills its sessions, it just ungroups them.

Custom launchers (and a built-in Copilot)

Until now cordless had three profiles: shell, claude, codex. v0.8 makes profiles yours. Drop this in ~/.cordless/config.json:

"profiles": {
  "api": { "command": "pwsh", "args": ["-NoLogo"], "cwd": "C:/src/api" },
  "notes": { "command": "nvim", "args": ["~/notes.md"] }
}

…and cordless new api spawns it directly (resolved against the daemon’s PATH, not a shell string — no sh -c injection surface). A missing executable doesn’t crash anything; it shows as unavailable with a reason, and cordless profiles lists every launcher with its source and availability.

And because the agent world moved, v0.8 ships a built-in copilot profile — the standalone GitHub Copilot CLI — right next to claude and codex. The nice part: attention detection is now preset-driven, so copilot (and any custom profile you tag attentionPreset: "agent") gets the same waiting / finished heuristics the other agents get, for free.

Rename tabs

Small feature, big daily quality-of-life. cordless rename <id> "API migration", or the dashboard e key, or a long-press on the phone. Titles are Unicode-normalized, control-stripped and length-capped, an empty title restores the generated default, and the change broadcasts live to every connected client (with a monotonic revision so a stale update can’t clobber a newer one).

Persisted history — survive the reboot

This is the one that turned into a proper engineering story. A cordless session already survives a daemon restart (it reopens the same shell in the same directory). But it came back blank — you lost the scrollback. v0.8 fixes that: the daemon persists a capped, plain-text copy of each session’s scrollback (2000 lines / 512 KB, gzipped, user-only) and, on restore, shows it as frozen context above the reopened session with a ── session reopened after system restart ── banner.

A couple of decisions worth calling out:

  • Normalized text, not raw bytes. Sol talked me out of persisting a truncated ANSI stream (it can start mid-escape-sequence and depends on terminal state you’ve discarded). We store logical lines from the headless terminal buffer instead.
  • Don’t write it into the fresh terminal. My first version injected the old scrollback into the reopened shell — which promptly wiped it, because a shell like PowerShell clears its own screen on startup. So restored history is kept beside the live session and rendered above it.
  • Save periodically, not just on shutdown. A reboot doesn’t send you a polite shutdown signal, so history is flushed every few seconds while the session runs.

The bug that only failed on Linux

Here’s the part I’m glad CI caught. My persisted-history tests were green on Windows and I shipped v0.8.0. The Linux and macOS CLI builds went red on the exact same test.

The cause is a lovely cross-platform trap. On a graceful stop, the daemon catches SIGTERM and runs shutdown(): it saves each session’s history, then kills the PTYs. Killing a PTY fires its exit handler — and that handler deleted the just-saved history and rewrote the “reopen these on restart” manifest without the now-exited session. So on Linux the session came back with no history; on macOS it didn’t come back at all.

Why did Windows pass? Because on Windows SIGTERM from another process is an uncatchable hard-kill — shutdown() never runs, the exit handler never fires, and the periodically-flushed history file just… survives. The platform that “worked” only worked by accident.

The fix is a _shuttingDown flag so the exit handler preserves history and the manifest during a graceful stop. What I like about it: I reproduced the Linux-only failure on Windows by driving shutdown() directly in a unit test (the harness’s SIGTERM can’t), so the regression is now locked shut on every platform. Re-tagged, rebuilt, and v0.8.0 went out clean with the full asset set.

How it was built

Same loop, tightened further: me on GitHub Copilot CLI, GPT-5.6 Sol as the design partner — and this time with a rule I’m keeping for good: every feature on its own branch, merged --no-ff, with clean well-documented code. The v0.8 program was six branches (feature/persisted-history, feature/custom-profiles, feature/copilot-profile, feature/session-rename, feature/session-groups, feature/group-ui-phone) plus a fix/history-shutdown. The daemon’s test harness grew to 24 suites — the pure profile/attention/render checks, live rename + groups over the WebSocket, the dashboard-driven resume regression, and persisted-history across a real restart — and CI runs all of it on Windows, Linux and macOS before building and smoke-testing the self-contained binary.

The good

The feeling I was chasing: open cordless with a dozen agents running and not feel underwater. The waiting ones surface (v0.7); the rest are filed into groups you named, launched from profiles you defined, titled how you think about them — and if the box reboots overnight, each one comes back with its history intact. It’s the browser-tabs promise, finally delivered for a swarm of terminals.

Try it

Part of the #AI4Good series. Built one day at a time. — @naveenneog