Dual Pane Atm

$dual-pane-atm — Opus + Codex collaborative ATM orchestration

You are the single orchestrator. One operator (this session or a lead pane) spawns exactly two worker panes — Claude Opus and Codex gpt-5.5 — assigns disjoint roles, verifies engagement, tends liveness, and synthesizes evidence. Workers do the work; you do logistics, reserves, and convergence. Do not let both panes become co-orchestrators.

Repeatable pattern for collaborative cross-model ATM sessions: architecture design, build+review pairs, explore+implement splits, and lighter author+refuter loops. Distinct from adversarial duels (dueling-idea-wizards — Codex skill) and from N-way bead queues ($using-atm).

When to use (routing table)

Front door: if unsure whether any ATM is warranted, run $automation-shape-routing first.

Critical constraints

• ⛔ LAW 0 — never claude -p / claude --print. Claude work runs in an interactive Opus pane; Codex runs via TUI goal lifecycle or codex exec when headless is explicitly requested.
• One bead = one whole skill. Dispatch $rpi, $implement, $research, etc. as a single invocable unit per pane — never decompose RPI phases into ATM steps.
• Worktree-per-bead when either lane edits tracked files. No shared checkout writes from panes.
• Partition before lock. If write-sets can be disjoint, assign ownership — use am reserve only when partition fails.
• Evidence over agreement. Collaborative sessions still require artifacts (diffs, test tails, gate output) — not mutual praise.

Orchestrator workflow

1. ROUTE    → confirm dual-pane fits (table above); pick work-split pattern
2. BEAD     → optional: BEADS_DIR="$(ao beads dir)" br create/claim; bead_id = join-key
3. SPAWN    → atm spawn with --reserve paths (see references/spawn-checklist.md)
3b. VERIFY   → `atm mapping --session="$SESSION"` — confirm pane numbers before any send
4. DISPATCH → verify first lane engaged; then second lane (--codex-goal for Codex)
5. TEND     → meter lies; atm save / codex preflight; gate interrupts first
6. SYNTH    → merge artifacts → .agents/dual-pane/<session>-report.md
7. CLOSE    → am release, atm kill session, br close with evidence

Checkpoint: first lane shows engagement (artifact, wait-goal-engaged, or CPU) before dispatching the second.

Spawn contract

Minimal collaborative spawn (from CEP duel pattern):

LABEL=<short-name>   # e.g. cep-duel, claim-overlay
SESSION="agentops--$LABEL"
BEAD_ID=<optional>   # join-key for coordination ledger + br notes
# Disjoint lane globs; for smoke-only runs use e.g. /tmp/dual-pane-opus/ /tmp/dual-pane-codex/
RESERVE_GLOBS="docs/contracts/ cli/internal/"   # space-separated globs, one --reserve value

atm spawn agentops --label "$LABEL" --no-user \
  --cc=1:opus --cod=1:gpt-5.5 \
  --reserve "$RESERVE_GLOBS" \
  --no-cass-context --ready-timeout=2m --json

atm mapping --session="$SESSION"   # confirm Opus/Codex pane numbers before sends

# Opus (pane 1 when --no-user): prefer plain send; --json optional
atm send "$SESSION" --pane=1 --file packet-opus.md \
  --no-cass-check --force-non-interactive
# Advisory: if `--json` exits 1 with empty stdout, retry without `--json`

# Codex (pane 2 when --no-user): goal lifecycle — NEVER bare slash send
atm codex preflight --session "$SESSION" --pane 2 --json
atm send "$SESSION" --pane=2 --codex-goal --file packet-codex.md \
  --no-cass-check --force-non-interactive --json
atm codex wait-goal-engaged --session "$SESSION" --pane 2 --json

Full checklist: references/spawn-checklist.md.

Pane verify: after spawn, run atm mapping --session="$SESSION" (or the equivalent pane-layout inspect documented in $using-atm) and match pane numbers to the table below before atm send.

--reserve: pass one quoted flag value listing all lane globs space-separated (e.g. --reserve "/path/opus/ /path/codex/"). Do not pass two separate quoted arguments or bare tokens after --reserve.

Pane addressing (see checklist table):

With user attach, --agent=1 == --pane=2 (Opus). Prefer --agent for workers when tri-pane.

Codex cold engage: optional --codex-goal on first send may timeout before the TUI is warm. Retry the send and/or run atm codex wait-goal-engaged again — advisory only; does not block spawn/teardown.

Tri-vendor extension (Opus + Codex + AGY)

Optional three worker panes — Claude Opus, Codex, and AGY (Antigravity interactive TUI) — with --no-user. This is not the anti-pattern “three-pane dual” (user attach + two workers); tri-vendor is worker-only and smoke-tested as agentops--dual-pane-agy-smoke.

LABEL=dual-pane-agy-smoke   # or your session label
SESSION="agentops--$LABEL"
RESERVE_GLOBS="/tmp/dual-pane-opus/ /tmp/dual-pane-codex/ /tmp/dual-pane-agy/"

atm spawn agentops --label "$LABEL" --no-user \
  --cc=1:opus --cod=1:gpt-5.5 --agy=1 \
  --reserve "$RESERVE_GLOBS" \
  --no-cass-context --ready-timeout=2m --json

Pane map (--no-user, tri-vendor): 1 = Opus, 2 = Codex, 3 = AGY (tmux window :1 on typical ATM layouts).

Sends:

Verify panes: prefer spawn --json panes[] or tmux list-panes -t "$SESSION:1". When Agent Mail is unavailable, atm mapping --session="$SESSION" may be empty despite healthy panes — do not treat empty mapping as spawn failure.

Observability gap: atm activity may list only Claude + Codex lanes and omit AGY; use tmux capture on pane 3 for AGY liveness.

Checklist block: references/spawn-checklist.md § Tri-vendor (+AGY).

In-session duel (no durable panes)

For a one-shot one-way-door decision ("duel it out"), you don't need persistent panes — run the same mixed-model duel in-session:

• Spawn ≥3 perspective subagents via the Agent tool with model: override (e.g. opus + fable) — each argues one opposed thesis, attacks the others, names its own weakness. Independent contexts = a real duel.
• Add the cross-family voice with codex exec "<prompt>" </dev/null (</dev/null dodges the exec stdin-stall). Never claude -p (LAW 0).
• Winnow to a SynthesisPacket; opposed theses that converge on the same slice are the signal. This is the substrate $discovery's fanout gate runs.

Durable panes (above) for multi-session/long-running work; in-session for a single bounded decision. $reverse-engineer routes one-way-door steals here.

Work-split patterns

Pick one before spawn; declare it in the coordination ledger and both packets.

Matrix + selection guide: references/work-split-matrix.md.

Dispatch

• Whole skills per pane — e.g. atm send … --file packet.md where packet contains $implement ag-1234 or $rpi ag-1234 --auto, not per-phase ATM glue.
• Codex: always --codex-goal + preflight + wait-goal-engaged.
• Claude: direct --file or inline prompt; interactive pane only.
• Headless Codex only when operator explicitly requests it — use $codex-exec, not a TUI pane.

Example packets:

# packet-opus.md
$implement ag-xyz — own docs/contracts/claim-registry.yaml only.
Write progress to br note on ag-xyz every 30m. Coordinate via am; reserve before edit.

# packet-codex.md
$implement ag-xyz — own cli/internal/gates/claim*.go only.
Run tests; post test_tail to br note. Do not touch docs/contracts/.

Coordination

Join-key: bead_id (or epic id) threads br notes, reserves, and optional ledger. Both lanes reference the same id in mail subjects and commit messages.

Agent Mail (am):

am macros start-session   # each pane once
am file_reservations reserve <proj> <agent> "<path/glob>"
# cross-lane: am mail send --from <me> --to <peer> --subject "ag-xyz: …" --body "…"

Worktree-per-bead: mandatory for implementation splits — shared checkout discipline.

Optional ledger (.agents/dual-pane/coordination.json):

{
  "session": "agentops--cep-duel",
  "bead_id": "ag-xyz",
  "pattern": "disjoint-ownership",
  "lanes": {
    "opus": {"pane": 1, "reserve": ["docs/"], "skill": "$implement"},
    "codex": {"pane": 2, "reserve": ["cli/"], "skill": "$implement"}
  },
  "artifacts": [],
  "converged": false
}

Orchestrator updates artifacts and flips converged at synthesis. Ledger pane values assume --no-user (Opus 1, Codex 2); use 2/3 when a user pane is present.

Operator tending

This skill owns spawn + split + dispatch; live tending defers to $using-atm §Observing lanes and $vibing-with-ntm tick loop.

Essentials:

1. Meter lies — atm activity / context-% freeze for Codex; never respawn from meter alone.
2. atm save <session> — Claude pane truth; for Codex use atm codex palette-state --json / preflight --json.
3. Artifacts beat narrative — PR, branch, output file, br show, test tail.
4. Gate interrupts first — answer ACTION NEEDED / merge gate before broad watch.
5. Verify lane 1 before lane 2 — boot-race drops silent sends.

Convergence criteria

Session is done when all hold:

• Each lane's declared deliverable exists (file, PR, or bead note with evidence).
• No unresolved am reservation conflicts; write lanes released or handed off.
• For implementation splits: tests/gate pass on merged or separately verified trees.
• Orchestrator synthesis written (report or br close reason cites both lanes).
• atm kill agentops--<label> after capture — do not leave idle duel panes.

Anti-patterns

• ❌ Shared checkout writes from both panes — worktree-per-bead always.
• ❌ Decomposing $rpi into ATM steps — dispatch the whole skill once.
• ❌ Love-fest without evidence — require test tails, diffs, or gate output.
• ❌ Adversarial scoring when you need a build — use dueling-idea-wizards instead.
• ❌ Three-pane "dual" (user + two workers) — that's $using-atm attach + workers; re-scope. Tri-vendor worker-only (Opus + Codex + AGY, --no-user) is a documented extension above — not the same anti-pattern.
• ❌ claude -p for Codex parity — interactive pane or codex exec only.

Codex twin

Per AGENTS-CODEX.md: after stabilizing this skill, manually mirror to skills-codex/dual-pane-atm/{SKILL.md,prompt.md} and run scripts/regen-codex-hashes.sh --only dual-pane-atm. Not auto-generated.

References

• references/spawn-checklist.md — preflight + first-dispatch gates
• references/work-split-matrix.md — pattern selection + reserve examples
• references/dual-pane-atm.feature — acceptance scenarios for preflight and work-split gates
• $using-atm — substrate spawn, codex preflight, meter lies
• $vibing-with-ntm — tending tick loop once panes are live
• $automation-shape-routing — shape 0 vs ATM vs swarm front door