Step 9: Convergence verify

Sub-agent type: explore; budget: 3 min.

Inputs

• PrNumber.
• The pushed HeadOid from step 7 (for the independent sanity check).
• Whether the loop is in normal mode or single-iteration mode (decided at step 1).

Return contract

{ converged, head_oid, latest_review_commit_oid, submitted_at,
  open_thread_count, open_threads_awaiting_reply, escalated_threads }

converged is the single source-of-truth boolean — Converged: true returned by 02-check-review-status.ps1.

Procedure

Run the status check, passing -SingleIteration iff the loop took the fallback at step 1:

pwsh ./scripts/02-check-review-status.ps1 -PrNumber <n>
# single-iteration variant:
pwsh ./scripts/02-check-review-status.ps1 -PrNumber <n> -SingleIteration

Then run an independent HEAD-vs-LatestCopilotReview.commitOid sanity check — the parent's recorded HeadOid from step 7 should match HEAD and (in normal mode) match the latest review's commitOid.

Decision: loop back or exit

After the status check, the parent agent must branch on converged:

if converged == true:
    run step 10 once (cleanup outdated)
    call task_complete with proof (HeadOid, LatestCopilotReview.commitOid, submittedAt)
    DONE — exit the loop
else:
    # non-converged = a fresh Copilot finding OR an unresolved human thread.
    # round = count of Copilot review submissions in the PR's history,
    #         read deterministically from the API (NOT a mental tally):
    #             pwsh ./scripts/09-review-round.ps1 -PrNumber <n>   -> {Round, RecapDue}
    if RecapDue == true:                        # Round is 10, 20, 30, ...
        RUN THE RECAP GATE (see "Round cap & recap gate" below) BEFORE looping:
            recap ALL prior rounds, then pick CONTINUE / REVERT-AND-SHIP / HAND-OFF.
            CONTINUE        -> fall through and start another round
            REVERT-AND-SHIP -> drop drifted commits, ship the in-scope result, exit
            HAND-OFF        -> escalate to the user with the recap, exit
    GO BACK TO STEP 1 — start another round
    (re-trigger via 01-request-review.ps1, wait via 02-wait,
     list via 03-list-threads, triage, fix, push, reply+resolve,
     re-check via this step)

A non-converged result is never terminal on its own — each round addresses the open review feedback on the previous round's HEAD, whether that's a Copilot finding or a human review comment (this skill handles both). The loop terminates only when there are no new review comments from either source AND every open thread — Copilot or human — has a reply from the agent (a thread the agent escalated to the user counts as replied; it stays open in OpenThreadCount as an explicit hand-off, not as loop work). But "never terminal" must not be read as "infinite": a bot-review loop has no guaranteed fixed point and can drift into over-engineering or oscillation. No script enforces a cap or stops the loop — capping is a reasoning decision the parent owns at the round-cap recap gate below. What is scripted is the round count itself (09-review-round.ps1), so the gate's trigger is deterministic rather than a fallible mental tally (and oscillation — the same finding re-raised across rounds — is broken earlier per 04-triage.md).

-SingleIteration mode is the one exception: by definition, it runs one round only (the trigger path is unavailable), and the converged result is taken as terminal whichever way it goes.

Convergence semantics

02-check-review-status.ps1 implements a PR-state guard plus three Converged branches (see the Converged = if (...) block near the end of that script for the canonical source):

• PR State guard (overrides everything) — if State != 'OPEN' (CLOSED / MERGED), Converged: false regardless of all other flags. The agent cannot push to a non-OPEN PR; surface the state change to the user and abort the loop rather than calling task_complete.
• Normal (Copilot-driven) mode — a Copilot review exists OR CopilotPending: true: Converged: true iff ReviewAtHead && NoNewComments && OpenThreadsAwaitingReply == 0.
• Single-iteration mode (-SingleIteration passed because the loop took the fallback at step 1): Converged: true iff OpenThreadsAwaitingReply == 0. The stale-review checks can never advance without a new Copilot review, so they're omitted.
• No Copilot review ever observed AND not pending (brand-new PRs with zero findings, or PRs where the trigger silently failed and the script wasn't called with -SingleIteration): Converged: true iff OpenThreadsAwaitingReply == 0. Do NOT trust this as "loop done" before step 1 has fired — it just means there's no human-thread work pending. The parent agent MUST run 01-request-review.ps1 first (per step 1) and re-check; treating brand-new-PR convergence as terminal will short-circuit the entire loop.

OpenThreadCount MAY be > 0 when escalated-to-user threads stay open — that's an explicit human hand-off, not a loop failure. Return the list of escalated thread_ids so the parent can include them in the convergence proof.

Round cap & recap gate (circuit breaker)

No script enforces a max-rounds cap or stops the loop — a hard number can't tell a productive round from a drifting one. Instead the parent agent runs a recap gate as reasoning: default STOP at every 10th round (10, 20, 30, …) before looping back to step 1, recap all prior rounds, and decide whether the loop is still serving the PR's original scope.

What is scripted is the count, so the gate's trigger is deterministic instead of a fallible mental tally. A round is one execution of step 1 — one Copilot-review trigger at the top of the loop — which produces exactly one Copilot review submission. 09-review-round.ps1 counts those submissions straight from the PR's API history and reports whether the cadence is hit:

pwsh ./scripts/09-review-round.ps1 -PrNumber <n>
# {"PrNumber":<n>,...,"Round":20,"RecapInterval":10,"RecapDue":true}

Run it at the top of the non-converged branch and gate on RecapDue. Because the count is derived from history, not remembered, it can't drift even across a 100+ round run — the exact failure this gate exists to catch. The cap counts review rounds (Copilot review submissions), not sub-agent calls, tool calls, or individual fix edits — so a round that triages five threads still counts as one. The cadence is the -RecapInterval knob (default 10). The script reports the trigger only; it never decides the verdict.

This exists because an unbounded bot-review loop is the failure mode this skill was built to survive: a real run drifted for 156 rounds — later rounds "fixing" things the PR never set out to change, eventually reverting their own earlier fixes. The gate catches that class of drift early, every 10 rounds, instead of once at the end.

What the recap reviews (ALL prior rounds, not just the last 10)

1. Original PR scope — the issue/PR title and the diff at the PR's base. This is the yardstick; everything else is measured against it.
2. Per-round ledger — for each round so far: the Copilot finding, the disposition (fixed / declined / escalated), and the resulting change (files + intent in one line).
3. Drift signals across the whole history:
   • Out-of-scope — a change that doesn't trace back to the original issue/PR goal (new feature, adjacent refactor, polish the PR never promised).
   • Over-engineering — defensive layers, abstractions, or config added solely to satisfy bot nits, not the PR's actual goal.
   • Wrong-direction — a fix that later rounds had to undo, work around, or re-fix (self-revert / oscillation across rounds).
   • Belongs-in-separate-PR — a legitimate improvement that is nonetheless unrelated to this PR's stated change.
   • Scope/complexity growth — diff size or file count climbing while the original goal was met rounds ago.

Verdicts

The trigger is scripted but the verdict is agent reasoning — deliberately. 09-review-round.ps1 makes the count deterministic (so the gate can't be missed), but which verdict to pick stays a judgment call: no number can tell a productive round from a drifting one. The recap is cheap (read the per-round commits + the PR base diff); the cost of skipping it is another runaway loop.

• Trust 02-check-review-status.ps1's Converged flag, not your own re-derivation. The script enforces all three conditions (normal mode) or the simplified condition (single-iteration) and is the canonical source.
• Don't call task_complete until converged == true. Print the proof (HeadOid, LatestCopilotReview.commitOid, submittedAt, OpenThreadsAwaitingReply: 0, list of escalated threads if OpenThreadCount > 0) in the completion message.
• -SingleIteration is sticky to the fallback decision. If step 1 took the fallback, every step 9 in this loop uses -SingleIteration; don't flip it mid-loop.
• PR State != OPEN aborts the loop. If State is CLOSED or MERGED, Converged is forced false by the script's state guard. The parent agent cannot push to a non-OPEN PR — surface the state change to the user and stop the loop rather than retrying or calling task_complete.