claude_mac/lib/challenge-plan.md

Challenge the plan — shared orchestrator include

Runs in the ORCHESTRATOR MAIN LOOP after a plan / reflection is elaborated and BEFORE it is executed. Turns a fresh plan into a hardened one by attacking it from three independent angles, then RE-THINKING every aspect a challenger lands. Loop + synthesis decisions live here, in the main loop (BDR-066: reflection runs on the big model; verify-secure-loop.md: fresh blind gates, decisions in the loop). It never merges, executes, or edits code — it hardens the plan and hands it to the orchestrator's existing human gate.

The challenge is ADVISORY into that gate — no new hard block — but a BLOCKER is never silently carried past: it is either closed by a NAMED plan change or explicitly deferred for the human.

Inputs the caller must have ready

• PLAN: path to the plan ON DISK. If your plan is still inline (a printed checklist / diagnosis / fix plan), FIRST persist it to .claude/tasks/plans/<date>-<slug>-<HHMM>.md — the challengers read from disk and judge blind, exactly like the verifier reads the contract.
• KIND: build-plan | proposals | fix-bundle — tunes the lens framing below; the mechanism is identical.
• SCOPE: the files/dirs the plan touches (grounds the critique).
• CONSTRAINTS (optional): the decided trade-offs / rejected alternatives from the design step, so a lens does not re-litigate a settled choice.

Nominal path is cheap for a small, clean plan: three parallel challengers return SOLID, synthesis is a no-op. It only costs more when a lens lands a real finding — which is the point.

DISPATCH — three fresh challengers, in parallel, blind

Dispatch THREE fresh plan-challenger subagents IN PARALLEL, one per LENS, each blind to the others and to this conversation:

Agent(subagent_type="plan-challenger", description="challenge:<lens>", prompt="""
  PLAN: <the PLAN path>
  LENS: <correctness | robustness | simplicity>   # one per agent — all three
  SCOPE: <SCOPE>
  CONSTRAINTS: <CONSTRAINTS, if any>
""")

MODEL (BDR-076, supersedes the BDR-066 inherit): plan critique is AUDIT JUDGMENT — the challengers are model: opus-pinned in their frontmatter: a big tier, session-independent, off the session model. The session model (Fable) keeps only this loop — synthesis, RE-THINK, gate. Never sonnet: that would silently downgrade the judgment. (The executor gates stay sonnet.)

Lens framing by KIND (the agent's three lenses, read against the artifact):

• build-plan — will it WORK / will it BREAK / is it needlessly COMPLEX.
• proposals — are these the RIGHT items & priorities / what did the audit MISS or under-rate as risk / is the backlog over- or under-scoped.
• fix-bundle — will each fix ACHIEVE its goal / could it BREAK or regress the page / is there a simpler fix, or an unnecessary one.

FAIL-SAFE — never fail open

A challenger that returns a malformed/empty verdict, a missing PROOF, or dies → retry ONCE with a fresh challenger; a 2nd failure on that lens → STOP and escalate to the human, NAMING the lens. Never carry "plan challenged" into the gate on a silently dropped lens (verify-secure-loop.md: "a mute verifier is NEVER a PASS").

SYNTHESIZE + RE-THINK (main loop, big model)

Parse each CHALLENGE — LENS: … — VERDICT: line and merge the FINDINGS:

• Severity-driven, not consensus. Any [BLOCKER] from ANY single lens is must-address — the lenses are orthogonal, so a lone security/rollback finding is real, never outvoted by lens-count. Cross-lens agreement only RANKS the MINORs.
• RE-THINK the aspect the challenge pointed at. For each BLOCKER (and each MAJOR you accept): revise the plan on THAT aspect — a NAMED, diffable change to the plan, never a self-authored "addressed" line. A BLOCKER you consciously keep is tagged [deferred <date>] for the human to accept at the gate.
• Re-challenge once if the plan materially changed — a fix can open a new flaw. Re-persist the revised PLAN, dispatch ONE fresh confirmation challenger, max 1 extra pass, then the gate.

OUTPUT — into the existing human gate

Feed the orchestrator's gate:

• the REVISED plan, and
• a CHALLENGE SUMMARY: each BLOCKER raised → the named change that closed it; anything [deferred]; and any lens that failed to return.

The human remains the decider.