tmux-layout — Operator-Side Visualization Substrate

Status: PROPOSED per ADR-0007 (docs/adr/0007-tmux-visualization-substrate.md). Opt-in skill — NOT default. Project-instruction file resolution: this is CLAUDE.md on Claude Code / Cursor IDE; the equivalent on Codex CLI is AGENTS.md. See skills/_shared/instruction-file-resolution.md.

Purpose

Render a prepared tmux layout for operator-side observability of the session's asynchronous side-channels — STATE.md updates, CI status, events.jsonl wave/gate transitions. NOT a coordinator chat surface, NOT a wave-agent host. The coordinator chat remains in the operator's original terminal, period (per AUQ-001 in .claude/rules/ask-via-tool.md).

When to Use

During a long deep-session when you want CI status visible alongside Quality-Gate output without polling glab ci status manually.
During /debug Phase 2 hypothesis testing (use --layout debug).
Anywhere tail -F .claude/STATE.md + a CI watcher would speed up your loop.

When NOT to Use

For wave-agent visualization — wave agents are in-process Agent() calls; no PID, no TTY, no pane to attach.
For autopilot multi-story panes — autopilot.jsonl currently shows 11 entries / 8 dry-runs; below the value threshold for a pane-per-story UI.
As your coordinator chat surface — that stays in the terminal where you invoked /tmux-layout.

Usage

/tmux-layout                        # default layout (4 panes)
/tmux-layout --layout debug         # debug layout (4 panes, /debug companion)
/tmux-layout --json                 # machine-readable output (no attach)
/tmux-layout --session-name my-ws   # custom tmux session name
/tmux-layout --force                # replace existing session (PSA-003 escape hatch)
/tmux-layout --help                 # full CLI usage

The skill prints a one-line tmux command. Paste it into a SECOND terminal (do not run it where /tmux-layout was invoked). That second terminal becomes the layout. Your original terminal (the coordinator chat) stays where it is.

Default Layout (4 panes)

Pane	Content	Command
1	Shell (operator scratch — NOT claude)	`bash` (interactive)
2	STATE.md tail	`tail -F <state-dir>/STATE.md`
3	CI watch (poll-loop wrapper)	`while true; do clear; glab ci status --pipeline-id LATEST --output json \| jq ...; sleep 15; done`
4	events.jsonl wave/gate filter	`tail -F .orchestrator/metrics/events.jsonl \| jq --line-buffered 'select(.event \| test("wave\|gate\|spiral"))'`

<state-dir> is resolved via resolveStateDir() from scripts/lib/platform.mjs (.claude/, .codex/, or .cursor/). Pane 3 command is vcs-aware (glab for gitlab, gh pr checks for github, informational echo fallback when no CLI).

Debug Layout (4 panes — `--layout debug`, depends-on #562)

Pane	Content	Command
1	Shell (operator scratch)	`bash` (interactive)
2	Hypothesis-test runner	`npm test -- --watch <scope>` (or per-skill-config)
3	Debug-artifact tail	`tail -F .orchestrator/debug/*.md`
4	Diff-watch	`watch -n 2 'git diff --stat \| head -30'`

Architecture

Three sibling modules under scripts/lib/tmux-layout/:

layouts.mjs — renderDefaultLayout(), renderDebugLayout(), detectVcsCommand().
vcs-detector.mjs — detectVcsCommand({config, projectRoot}) returns {bin, args, fallback, blocking} per vcs key.
tmux-shell.mjs — detectTmuxVersion(), session-collision policy helpers.

Entry point: scripts/tmux-layout.mjs (parseArgs from node:util, dispatcher to layout functions).

PSA-003 Compliance

Session-collision policy: refuse + --force. The skill NEVER kills, overwrites, or modifies a tmux session it did not create unless the operator passes --force explicitly. See .claude/rules/parallel-sessions.md § PSA-003.

AUQ-001 Compliance

The coordinator chat (where AskUserQuestion fires) stays in the operator's ORIGINAL terminal. Pane 1 of the tmux layout is intentionally a scratch shell, NOT a new claude session — there is no second AUQ surface, no decision-authority split. See .claude/rules/ask-via-tool.md § AUQ-001.

Telemetry & Promotion Gate (#563)

This skill emits structured events to .orchestrator/metrics/events.jsonl:

tmux-layout.invoked
tmux-layout.degraded (tmux missing, version too old, session collision without --force, etc.)
tmux-layout.completed (when the user closes the tmux session)

Promotion criteria from opt-in skill to default-recommended in session-start banner: invocation count ≥ 5 across ≥ 3 distinct deep sessions over ≥ 2 calendar weeks, layout-completion rate ≥ 80%, zero AUQ-001 / PSA-003 regressions. See ADR-0007 § Follow-ups.

Troubleshooting

tmux not found → install: brew install tmux (macOS) / apt install tmux (Linux). Minimum tmux ≥ 3.0.
Session already exists → use --force (acknowledges PSA-003) or --session-name my-other.
CI pane shows nothing → glab or gh not installed, or vcs: not set in ## Session Config. Pane will show a clear fallback message.