Phase-Open / Phase-Close Prompt Pair

ELI5

Two prompts bookend every phase. The opener checks the door is unlocked before letting you in. The closer checks the room is tidy before letting you out — and even when the room looks tidy, it forces a final friction sweep so anything missed leaks into the next phase as a numbered milestone, not into the closing phase as a retrofit.

Technical Deep Dive

The pair in motion

sequenceDiagram
  autonumber
  participant H as Human
  participant P as Planner (01-phase-open)
  participant I as Implementer
  participant A as Auditor
  participant R as Reviewer (02-phase-close)
  participant V as Verification round (03)
  participant M as MILESTONES.md
  participant D as docs/decisions/

  H->>P: paste 01-phase-open.md (N)
  P->>P: re-read intent, MILESTONES §N, prior close, MR-1/2/10/11
  P->>P: Step 2 — entry criteria verdict (met/not-met/n/a)
  alt any not-met
    P-->>H: stop + surface missing
  else all met
    P->>D: write YYYY-MM-DD-phase-N-open.md
    P->>M: status=open, set Active phase pointer
    P-->>H: handoff: M{N}.1 + owner subagent
  end

  loop per milestone
    I->>A: ship + session log
    A->>I: audit.fail back-edge if blocked
    A->>A: pass / advisory
  end

  H->>R: paste 02-phase-close.md (N)
  R->>R: Step 1 verify acceptance evidence per gate
  alt any block
    R-->>I: route back, stop
  else all pass
    R->>V: invoke 03-verification-round inline
    V-->>R: findings list
    R->>R: classify closed/in-budget/deferred
    R->>M: append M{N+1}.x.y for deferred (same commit)
    R->>D: write YYYY-MM-DD-phase-N-close.md
    R->>M: phase N=closed, phase N+1=next
    R-->>H: deferred count + next prompt
  end

Phase-open — the six steps (01-phase-open.md)

1. Re-read ground truth — intent.md, MILESTONES § Phase N, prior phase-close decision doc, CLAUDE.md invariants + drift watches, META-RULES (MR-1, MR-2, MR-10, MR-11).
2. Check entry criteria — one-line verdict per criterion: met / not-met / n/a with citation. Any not-met → stop (overriding is how the system rots).
3. Re-evaluate scope — three questions: still serves north-star? deferred items still relevant? gates still falsifiable? Vague gates (“we’ll know it when we see it”) get flagged.
4. Write the phase-open decision doc at docs/decisions/<TODAY_ISO>-phase-N-open.md — short on purpose; richness lives in MILESTONES.md and the prior close.
5. Update MILESTONES.md — set status open, point Active-phase block at this phase, set open date.
6. Hand off — first milestone owner subagent named; do not start implementer work in the open session.

Phase-close — the six steps (02-phase-close.md)

1. Verify acceptance evidence per gate — auditor evidence located in docs/roles/auditor/outputs/, vague evidence is block. Any block → route to implementer; the close prompt was premature.
2. Run the verification round inline — read prompts/03-verification-round.md as the next instructions, do not start a new session. MR-10 — even smooth phases run one.
3. Classify and update MILESTONES.md — deferred items as M{N+1}.x.y before the close decision doc commits; phase N → closed; Active-phase pointer to N+1 (next).
4. Write the phase-close decision doc — fixed structure with ## Acceptance gate verdicts, ## Invariants table, ## Friction budget (closed/in-budget/deferred subsections), ## Anti-shape audit per drift watch, ## Handoff to phase N+1.
5. Self-audit — every deferred has a milestone ID; no block verdicts; auditor evidence cited; MILESTONES status correct; no MR-7 silent edits.
6. Hand off — counts of in-budget vs deferred; if deferred > 3, surface a warning (“Phase N deferred a lot. Consider re-reading scope before opening N+1.” — leading indicator of north-star realignment).

Why the prompts are deliberately interactive

CLAUDE.md (in petrova-hq) marks the prompts as load-bearing: “each prompt is deliberately interactive and stops at checkpoints; do not ‘streamline’ them by removing the stops.” The interactivity exists because the human is the right tiebreaker for not-met, block, drift suspicion, and the friction-budget classifications — agents prone to forward motion will paper over these without the explicit stop.

Phase-open writes vs phase-close writes

Key Terms

• Active phase pointer — block at MILESTONES.md top naming the currently open phase. Owned by planner on open, by reviewer on close.
• Friction budget — ## Friction budget section of the phase-close decision doc; the place MR-2 classifications live.
• audit.fail back-edge — legitimate remediation loop in the AGENTS.xml handoff graph (auditor → implementer); exempt from the intra-phase DAG check.

Q&A

Q: What forces phase-close to invoke the verification round inline? A: 02-phase-close.md Step 2 says explicitly: “invoke prompts/03-verification-round.md inline (do not start a new session). Read it as your next instructions, perform the round, then return here.” MR-10 makes the round mandatory; running it inline keeps the reviewer’s context for classification.

Q: What happens when a phase-open Step 2 verdict is ‘not-met’? A: The planner stops and surfaces what’s missing. The prompt explicitly forbids overriding: “don’t override it. The criteria exist because the prior phase’s verification round earned them. Override is how the system rots.”

Q: Where do deferred friction items land before the close commit lands? A: As M{N+1}.x.y entries in MILESTONES.md, written in the same commit as the phase-close decision doc. Step 3 enforces ordering: deferred items → MILESTONES.md update → close decision doc. Otherwise the lineage between the deferred item and its phase-N origin breaks.

Examples

Reviewer pastes 02-phase-close.md for KAHN’s Phase 6. Step 1 verdicts: 3 gates pass, 1 advisory. Step 2 round surfaces six findings: one trivial typo (closed), one accepted partial-coverage note (in-budget — “telemetry seam ships in M7.3”), four deferred. Step 3 writes M7.2.1, M7.2.2, M7.3.1, M7.3.2, then writes 2026-05-06-phase-6-close.md, then flips MILESTONES status. Step 6 hands off with deferred=4 warning since count >3.