Model committee

Model Committee

Run GPT-5.6 "Sol" and Claude Opus 5 as a deliberating committee under a Claude Opus 5 chair. Keep the line to model-council-voting sharp: a council measures independent disagreement, while this committee deliberately exposes each member to the other's argument and returns one decision.

Read reference/protocol.md completely before running a committee. It carries the use-case gate, the brief template, the three round contracts, the decision rule, and the decision.md schema.

The two sibling skills deliberate the same pairing and differ only in who chairs after round 3: model-committee-sol (GPT-5.6 "Sol" chairs, with the GPT member dropped to gpt-5.6-terra so the chair is not also a member) and model-committee-fable (Fable 5 chairs). Score aggregation and the tie rule are mechanical whoever chairs; schema validation and compatible-component synthesis carry the chair's own judgment, which is what the choice of variant buys.

Gate the workflow

Run only when the user invokes /model-committee or asks for Sol and Opus to deliberate. Six external calls draw plan credits or API spend on both providers — surface that and get confirmation unless the user has already accepted it. Apply the protocol's use-case gate first; if the task does not qualify, name the right alternative and call neither model.

Before the first call:

1. Confirm the decision that must be returned.
2. Confirm the material may be sent to both providers.
3. Precommit the evaluation criteria, weights, and tie rule.

Preflight both members

Resolve SKILL_DIR as the directory containing this SKILL.md, then run:

"$SKILL_DIR/scripts/codex-member.sh" --check
"$SKILL_DIR/scripts/claude-member.sh" --check

Default pins:

• GPT member: gpt-5.6-sol (reasoning effort: xhigh)
• Claude member: claude-opus-5 (reasoning effort: high)

These are exact pins, not moving aliases. If one is unavailable, report it and ask whether to stop or use a named replacement — never substitute silently.

Run the committee

Create a temporary working directory such as .committee-tmp/<slug>/. Follow the protocol's prompt contracts and produce these artifacts:

brief.md
round-1-gpt.prompt.md       round-1-gpt.md
round-1-opus.prompt.md      round-1-opus.md
round-2-gpt.prompt.md       round-2-gpt.md
round-2-opus.prompt.md      round-2-opus.md
round-3-gpt.prompt.md       round-3-gpt.md
round-3-opus.prompt.md      round-3-opus.md
decision.md

Invoke each member through the bundled read-only driver:

"$SKILL_DIR/scripts/codex-member.sh" \
  --prompt-file <prompt.md> --out <output.md> --effort xhigh -C <working-directory>

"$SKILL_DIR/scripts/claude-member.sh" \
  --prompt-file <prompt.md> --out <output.md> --effort high -C <working-directory>

Launch both calls in a round concurrently when the runtime supports it. Sequential execution is acceptable only if the second prompt was frozen before the first result arrived — otherwise round 1 stops being blind.

Chair without becoming a third debater

The chair is Claude Opus 5 — normally the model already running in-session, but verify rather than assume. Claude Code injects a line into every session's context naming the model actually running (e.g. "You are powered by the model named …"); read it before picking a branch. This is the failure a sibling orchestration skill (fable-orchestrate) hit in practice: a benchmark run silently executed a full task under the wrong model and recorded it as the intended one, because nothing checked.

On Opus, chair directly at /effort high — aggregation and the tie rule are mechanical, but the compatible-component synthesis and the escalate-or-synthesize call are where the effort earns its cost. On any other model, delegate only the post-round-3 chair step, bundling the brief and all round outputs into chair.prompt.md:

"$SKILL_DIR/scripts/claude-member.sh" \
  --prompt-file chair.prompt.md --out decision.md --model claude-opus-5 --effort high -C <working-directory>

Chairing is procedural: validate the round outputs against the protocol's schemas, aggregate the predeclared weighted scores, apply the precommitted tie rule, and synthesize only components both revisions explicitly marked compatible. Never introduce a new substantive option, and never break a tie by confidence, eloquence, or model identity — the chair sharing a family with the Claude member is precisely why it must not vote a third time. If the evidence stays genuinely unresolved, return the exact fork to the user; a forced but unsupported answer is not committee consensus.

Deliver

Return a compact decision record containing:

1. use case and why committee treatment was justified;
2. decision and decision rule;
3. strongest reasons and evidence;
4. what changed during deliberation;
5. surviving dissent or uncertainty;
6. implementation or verification next step.

Delete .committee-tmp/ after delivery unless the user wants the full transcript kept. Implement only once the decision is accepted.