revealui-checkpoint

name	revealui-checkpoint
description	Checkpoint checklist for RevFleet sessions. Validates the 6 coherent-tracking surfaces, inventories tracking state, writes a rolling handoff fragment + workboard log fragment, re-renders CURRENT-HANDOFF/workboard locally for read convenience, and commits ONLY append-only fragments (docs/handoffs/rolling + .claude/workboard.d) per ADR 2026-07-23-jv-coordination-merge-model. Worktree-gated when a peer is live. Never commits derived CURRENT-HANDOFF.md or workboard.md. Never master-handoff regen or auto-merge with --admin.
license	MIT
allowed-tools	Bash, Read, Write, Edit
metadata	{"author":"RevealUI Studio","version":"0.12.1","website":"https://revealui.com"}

Checkpoint orchestrator. Run before ending a meaningful session to ensure the next agent can pick up cleanly. Wires together the 6 coherent-tracking validators + 4 inventory surfaces + writes a rolling handoff fragment (docs/handoffs/rolling/) + a workboard log fragment (.claude/workboard.d/), renders $JV_REPO/docs/handoffs/CURRENT-HANDOFF.md and workboard.md locally only (read convenience), and commits only append-only fragment paths (ADR 2026-07-23-jv-coordination-merge-model / jv#601). Concurrent sessions must not stack: unique fragment filenames merge without rewriting shared derived files. Then reports CHECKPOINT-READY + emits the archive-readiness next-agent prompt.

Authority on locations + tiers: master-handoff.md (active at docs/HANDOFF-*.md root; archive at docs/handoffs/archive/). Authority on doc-location enforcement: jv-doc-locations.md.

Load helpers:

. "$HOME/revfleet/revskills/scripts/lib/session-state.sh"

Step 1 — Resolve context

IDENTITY="$(ss_identity)"
REPO="$(ss_active_repo)"
JV_ROOT="$JV_REPO"
WORKBOARD="$JV_ROOT/.claude/workboard.md"
ISO_DATE="$(date -u +%Y-%m-%d)"
ISO_DATETIME="$(date -u +%Y-%m-%dT%H:%MZ)"
# Rolling handoff — always merged into this one file.
CURRENT_HANDOFF="$JV_ROOT/docs/handoffs/CURRENT-HANDOFF.md"

Rolling handoff read surface per ~/.claude/rules/model-allocation.md §Session handoff loop: $JV_REPO/docs/handoffs/CURRENT-HANDOFF.md (rendered). Durable write surface: docs/handoffs/rolling/<ISO>-<id>.md only. Every session adds a fragment rather than creating a dated handoff file. Renderer caps history (--max, default 12); optional --gc archives rolling fragments older than 7d (Step 4b).

Step 1b — Load the auto-checkpoint snapshot (fidelity source)

A session snapshot is captured mid-session by the /snapshot skill (nudged by the track-session context advisory at the soft-context line), while fidelity is still high. When one exists it is the PRIMARY source for the narrative sections in Step 4 — more trustworthy than reconstructing from now-deep session memory.

Resolve it by this session's id, never by mtime — a peer's snapshot must be structurally unreachable (GAP-317):

SNAP_DIR="$HOME/.claude/coordination/snapshots"
SID="${CLAUDE_CODE_SESSION_ID:-}"
SNAPSHOT=""
[ -n "$SID" ] && [ -f "$SNAP_DIR/$SID.md" ] && SNAPSHOT="$SNAP_DIR/$SID.md"
if [ -n "$SNAPSHOT" ]; then
  echo "snapshot for this session: $SNAPSHOT"
else
  echo "no snapshot for this session (${SID:-no-session-id}) — Step 4 falls back to session memory"
fi

If $SNAPSHOT is set it is unambiguously THIS session's (the filename equals $CLAUDE_CODE_SESSION_ID), so no content-matching guesswork is needed. READ it and use its five sections (Resume-From-Here, What-Shipped, Active-Constraints, Do-Not-Repeat, Open-Loose-Ends) as the spine of the Step 4 merge; they map onto the rolling file's sections. With no snapshot — no threshold was crossed, or /snapshot was not run — Step 4 proceeds from session memory as before. Do NOT fall back to the most-recent file on disk; an unmatched id means no snapshot for this session.

Step 2 — Run coherent-tracking validators

Capture pass/fail per check. Do NOT auto-fix anything destructive.

2a. Doc locations

cd "$JV_ROOT" && ~/revfleet/revealui/node_modules/.bin/tsx scripts/doc-locations-check.ts --quiet

Exit 0 = clean. Exit 1 = drift (e.g., handoffs at docs/handoffs/ top-level, lane plan missing).

2b. Workboard freshness

node "$JV_ROOT/scripts/workboard-check.js"

Read-only. Warns on stale Active Sessions / Coordination Notes / Log entries. Never blocks.

2c. MASTER_HANDOFF staleness

node "$JV_ROOT/scripts/master-handoff-staleness.js"

Recomputes staleness-status (FRESH / STALE / EXPIRED) in docs/MASTER_HANDOFF.md frontmatter. Read-only against body.

2d. Lane plans

node "$JV_ROOT/scripts/lanes-check.js"

Validates each lane's frontmatter + plan.md presence.

2e. M-1 ADR tracking-issue compliance

~/revfleet/revealui/node_modules/.bin/tsx "$JV_ROOT/scripts/m1-adr-tracking-check.ts" --base-ref=origin/main --head-ref=HEAD --mode=ci

Every ADR (post-2026-05-16 cutoff) must carry tracking-issue: frontmatter. The check needs a diff range: origin/main...HEAD scopes it to ADRs on the current branch not yet on main (empty on a fresh main → exit 0). Invoking it with no range exits 2 with a usage error — that was the Step 2e bug, fixed 2026-06-06. Requires origin/main to be fetched (the inventory step already hits the network, so a stale ref is the only failure mode).

2f. M-1 frontmatter staleness

~/revfleet/revealui/node_modules/.bin/tsx "$JV_ROOT/scripts/m1-frontmatter-staleness-check.ts" --mode=ci

Lane plan last-updated: must not be older than the most-recent ADR's date: field.

Step 3 — Inventory tracking state

Surface what's currently tracked. Read-only.

3a. branches.json — active branches

BRANCHES_JSON="$HOME/.claude/coordination/branches.json"
if [ -f "$BRANCHES_JSON" ] && command -v jq >/dev/null 2>&1; then
  ACTIVE_COUNT="$(jq '.branches | map(select(.status == "active")) | length' "$BRANCHES_JSON")"
  echo "active branches: $ACTIVE_COUNT"
  jq -r '.branches | map(select(.status == "active")) | .[] | "  - \(.project):\(.branch) (\(.pr // "no PR"))"' "$BRANCHES_JSON"
fi

3b. Open PRs across RevFleet repos

for repo in revealui revealui-jv revvault revdev revforge revkit revskills revcon; do
  count="$(gh pr list --repo RevealUIStudio/$repo --state open --json number 2>/dev/null | jq 'length' 2>/dev/null)"
  if [ "${count:-0}" != "0" ]; then
    echo "$repo: $count open"
    gh pr list --repo RevealUIStudio/$repo --state open --json number,title,headRefName --jq '.[] | "  - #\(.number) \(.title) [\(.headRefName)]"' 2>/dev/null
  fi
done

3c. .jv git state

cd "$JV_ROOT" && git -c core.fileMode=false status --short && echo "---" && git log --oneline -5

3d. Active lanes (from INDEX)

# Count rows in the generated lanes-index block.
awk '/^<!-- BEGIN GENERATED:lanes-index -->/,/^<!-- END GENERATED:lanes-index -->/' "$JV_ROOT/docs/lanes/INDEX.md" | grep -cE '^\| [a-z][a-z0-9-]+ \|'

3e. Master tier-1 surfaces

# DIRECTION.md last-modified mtime — flag if updated this session.
stat -c '%Y' "$JV_ROOT/.claude/DIRECTION.md"
# MASTER_PLAN.md staleness check is part of M-1 (covered by 2f).

3f. Pending hotfixes → durable (GAP-405; read-only)

Surface registered debt so wrap-up cannot clear without naming the durable follow-up. Prefer durable root-cause fixes; registry is admitted debt only. Control layer: revealui-harnesses hotfix (store ~/.local/share/revealui/hotfixes). Adapter thin entry still works.

# Prefer control-layer CLI; fall back to Studio adapter (forwards to control layer).
if command -v revealui-harnesses >/dev/null 2>&1 && revealui-harnesses hotfix store >/dev/null 2>&1; then
  revealui-harnesses hotfix check 2>/dev/null || true
  revealui-harnesses hotfix list 2>/dev/null || true
elif [ -f "$HOME/.claude/scripts/hotfix.js" ]; then
  node "$HOME/.claude/scripts/hotfix.js" check 2>/dev/null || true
  node "$HOME/.claude/scripts/hotfix.js" list 2>/dev/null || true
else
  echo "hotfix control CLI missing — build @revealui/harnesses (GAP-405)"
fi

Read-only. Capture output for Step 6 HOTFIXES and Step 4 fragment Owner-gated / Outstanding when any entry is pending. Do not call resolve here. Pending entries never block CHECKPOINT-READY alone, but they must appear under OUTSTANDING.

Step 4 — Write rolling handoff fragment + local render

Contention-free path (2026-07-21, amended 2026-07-23): do not hand-edit $CURRENT_HANDOFF when a peer may be live. Write a new fragment under docs/handoffs/rolling/, then render locally for the report/prompt. Sibling of workboard fragments (ADR 2026-07-04). Do not commit the render (ADR 2026-07-23-jv-coordination-merge-model; CI Coord paths guard fails PRs that edit CURRENT-HANDOFF.md / workboard.md).

Compose the delta PRIMARILY from the Step 1b snapshot when present, supplemented by session memory + Step 2-3 results. With no snapshot, fall back to session memory.

Security content: CITE, don't restate (owner ruling 2026-07-16). When the session touched security findings / exploits / confinement / crypto, the delta references the artifact only — never re-describes the technique. Applies to the fragment, the workboard log (Step 5), and the next-agent prompt (Step 8).

4a. Write the fragment

# Compose body with at least ## Last merge (renderer extracts it for the top block).
# Include Live board / In-flight / Ordered next / Owner-gated as needed.
HANDOFF_BODY="$(cat <<'EOF'
## Last merge

<ISO_DATE> — <IDENTITY>: <≤15 words what landed>

## Live board

| Surface | State |
|---------|--------|
| … | re-verify with gh |

## In-flight

- …

## Ordered next actions

1. …

## Owner-gated

- …

## Pending hotfixes (if any from Step 3f)

- none | list id — title — durable target
EOF
)"
printf '%s\n' "$HANDOFF_BODY" \
  | node "$JV_ROOT/scripts/handoff-fragment.js" --id "$IDENTITY"
# Local read convenience only — derived view, not a commit path:
node "$JV_ROOT/scripts/handoff-render.js"
# Optional GC of rolling fragments older than 7d:
# node "$JV_ROOT/scripts/handoff-render.js" --gc

Never create a dated docs/HANDOFF-YYYY-MM-DD-*.md for the rolling train. Prefer session-specific truth in the fragment (unique path). After peers land, git fetch + re-render so $CURRENT_HANDOFF reflects all fragments.

4b. Size control

Rolling history is capped by handoff-render.js --max (default 12 fragments). Older fragments age out with --gc (7-day mtime → docs/handoffs/archive/rolling/). Do not hand-prune GENERATED blocks.

Step 5 — Workboard log entry

Compose this session's Log line (do NOT hand-edit ## Log — the workboard ## Log block is now GENERATED from per-session fragments per ADR 2026-07-04-workboard-fragment-store, the contention-free write path):

- [YYYY-MM-DD HH:MM] <IDENTITY>: [CHECKPOINT] → rolling fragment only | tracking: <X pass / Y fail> | next: <one-line next action from §Ordered next actions>

Step 5b writes it as a fragment (.claude/workboard.d/log/<ts>-<id>.md — a new per-session file that can never collide with a peer) and re-renders workboard.md locally only, in the correct checkout (main for SOLO, the worktree for PEER). Set the volatile parts as single-quoted literals so a next-action containing backticks / $(…) / quotes is never command-substituted (§Ordered next actions holds exact commands + paths, which routinely use backticks):

TS="$(date -u '+%Y-%m-%d %H:%M')"
TRACK='<X pass / Y fail>'
NEXT='<one-line next action from §Ordered next actions>'   # single-quoted literal; a literal ' inside → close+reopen: '\''

Step 5b assembles the line with printf %s (never re-evaluates) and pipes it to workboard-fragment.js on stdin. Because the log line is a fresh file (never an edit to the shared workboard.md), it sidesteps both the rogue-workboard hook and the dirty-file guard, so this step can never strand the checkout.

Step 5b — Commit + converge the .jv delta (worktree-gated; fragments only)

DEFAULT: commit append-only fragment paths only and converge them to origin/test:

• docs/handoffs/rolling/**
• .claude/workboard.d/**

Never stage docs/handoffs/CURRENT-HANDOFF.md or .claude/workboard.md in a session checkpoint PR (derived renders; concurrent rewrites always conflict). CI Coord paths guard on revealui-jv fails those paths unless labeled coord:allow-render-commit (escape hatch only).

Local render in Steps 4–5 remains required so the CHECKPOINT REPORT and next-agent prompt can read a fresh board; after git fetch origin test, re-run handoff-render.js / workboard-sweep.js --render-only to refresh derived views.

Pass --no-commit to skip Step 5b and leave fragment writes UNSTAGED for owner review — then jump to Step 6 and list them under OUTSTANDING.

CRITICAL — never strand the main checkout. A naive commit on the MAIN .jv checkout was the root cause of the 8-session checkpoint-merge divergence: it left the main checkout on a chore/checkpoint-* branch that later merged+deleted, so every subsequent checkpoint merged onto the dead branch and never converged. The fix is the .jv Single-Writer Discipline — when a peer is live, do the commit from a throwaway $JV_REPO-wt/ worktree so the main checkout never moves.

Determine the writer mode (count live interactive, non-headless claude sessions):

PEERS="$(node "$JV_ROOT/scripts/jv-single-writer-check.js" --count 2>/dev/null \
  || (pgrep -af claude | grep -ivE ' -p |grep|pgrep' | grep -c claude))"
STAMP="$(date -u +%Y%m%dT%H%M%SZ)"
CMSG="/tmp/cmsg-ckpt-${STAMP}.txt"   # write the commit message here (Step 5b uses -F)

If jv-single-writer-check.js has no --count mode yet, the pgrep fallback is authoritative.

Throughout: core.fileMode=false on every .jv commit; explicit pathspec (fragments only) -- docs/handoffs/rolling .claude/workboard.d (NEVER stage CURRENT-HANDOFF.md, workboard.md, tmp/, or peer-WIP untracked); -F "$CMSG"; --body-file PR bodies; --head/--base explicit; merge-COMMIT only, never squash on .jv protecteds (repo squash disabled + label merge:merge-commit required by CI); add that label on the checkpoint PR; NO --admin/--no-verify/--force-push.

SOLO (PEERS ≤ 1) — commit on the current .jv branch (fragments pathspec only):

cd "$JV_ROOT"
BR="chore/checkpoint-${ISO_DATE}-${IDENTITY}"
# Step 4 already wrote handoff rolling fragment + local render. Workboard log:
printf -- '- [%s] %s: [CHECKPOINT] → rolling fragment only | tracking: %s | next: %s\n' "$TS" "$IDENTITY" "$TRACK" "$NEXT" \
  | node "$JV_ROOT/scripts/workboard-fragment.js" --kind log --id "$IDENTITY"
node "$JV_ROOT/scripts/workboard-sweep.js" --render-only
# Fragments only — do not add CURRENT-HANDOFF.md or workboard.md
git add docs/handoffs/rolling .claude/workboard.d
git -c core.fileMode=false commit -F "$CMSG" -- \
  docs/handoffs/rolling .claude/workboard.d
git push origin "HEAD:refs/heads/$BR"
gh pr create --base test --head "$BR" --body-file "$CMSG"
gh pr edit <n> --repo RevealUIStudio/revealui-jv --add-label "merge:merge-commit"
# Owner disposes merge unless authorized; always --merge (never --squash):
gh pr merge <n> --repo RevealUIStudio/revealui-jv --merge --delete-branch
git fetch origin test && git merge --ff-only origin/test
node "$JV_ROOT/scripts/handoff-render.js"   # refresh local derived view after land

PEER LIVE (PEERS > 1) — do NOT commit on the main checkout; use a dedicated worktree:

cd "$JV_ROOT"
WT="$JV_REPO-wt/ckpt-${ISO_DATE}-$$"; BR="chore/checkpoint-${ISO_DATE}-${IDENTITY}"
# Prefer fragment-only dirty state (rolling/ + workboard.d). If CURRENT-HANDOFF.md
# is dirty from a local render, leave it unstaged (or restore) — never commit it.
git fetch origin test && git merge --ff-only origin/test
git worktree add "$WT" -b "$BR" origin/test
cd "$WT"
# Re-write this session's fragments INTO the worktree:
printf '%s\n' "$HANDOFF_BODY" \
  | node "$JV_ROOT/scripts/handoff-fragment.js" --id "$IDENTITY" --base "$WT/docs/handoffs/rolling"
node "$JV_ROOT/scripts/handoff-render.js" --base "$WT/docs/handoffs/rolling" --out "$WT/docs/handoffs/CURRENT-HANDOFF.md"
printf -- '- [%s] %s: [CHECKPOINT] → rolling fragment only | tracking: %s | next: %s\n' "$TS" "$IDENTITY" "$TRACK" "$NEXT" \
  | node "$JV_ROOT/scripts/workboard-fragment.js" --kind log --id "$IDENTITY" --base "$WT/.claude/workboard.d"
node "$JV_ROOT/scripts/workboard-sweep.js" --render-only --workboard "$WT/.claude/workboard.md" --base "$WT/.claude/workboard.d"
# Fragments only
git add docs/handoffs/rolling .claude/workboard.d
git -c core.fileMode=false commit -F "$CMSG" -- \
  docs/handoffs/rolling .claude/workboard.d
git push origin "HEAD:refs/heads/$BR"
gh pr create --base test --head "$BR" --body-file "$CMSG"
gh pr edit <n> --repo RevealUIStudio/revealui-jv --add-label "merge:merge-commit"
gh pr merge <n> --repo RevealUIStudio/revealui-jv --merge --delete-branch
cd "$JV_ROOT" && git worktree remove "$WT"
git fetch origin test && git merge --ff-only origin/test
node "$JV_ROOT/scripts/handoff-render.js"

Cleanup + failure handling. On success the temp worktree is removed and the chore branch deleted (--delete-branch). On ANY failure — the initial converge is not a clean fast-forward, an unresolved stash pop conflict, or a push/merge error — DO NOT silently drop the delta: surface the stash ref (git stash list) or the worktree path, fall back to the --no-commit end state (writes left for the owner), and leave the main checkout on its original branch. Never leave the main checkout on a chore/checkpoint-* branch.

Step 5c — Prepare-for-exit verifier (read-only, runs after 5b converges)

Runs the seed prepare-for-exit workflow's read-only session-exit verifier (GAP-314 §5) — 7 report-only checks. Capture output verbatim. Check 6 may still phrase "CURRENT-HANDOFF.md committed"; under fragments-only the durable artifact is docs/handoffs/rolling/** (and workboard.d). Treat check 6 as PASS when the rolling fragment is on origin/test even if the derived render was not committed. Optional follow-up: update prepare-for-exit.js wording to "handoff fragments committed".

node "$JV_ROOT/scripts/prepare-for-exit.js"

Runs unconditionally, in both the default (5b committed) and --no-commit paths — under --no-commit its check 6 (handoff committed + pushed) is expected to WARN, which is informative, not a bug. Capture the full output verbatim; do not re-derive or re-implement its checks here. Exit code is always 0 (report-only, never blocks) — this step never changes the CHECKPOINT-READY verdict.

Step 6 surfaces this output as the PREPARE-FOR-EXIT section of the CHECKPOINT REPORT.

Step 5d — Archive the consumed snapshot + GC stale ones (GAP-317 lifecycle)

Now that Step 4 folded this session's snapshot into the rolling handoff, retire it so the active dir only ever holds live sessions' records (acceptance: none older than 7 days active). This is the agent-invoked mover — no hook writes these files, by the hooks read-only invariant.

SNAP_DIR="$HOME/.claude/coordination/snapshots"
ARCH="$SNAP_DIR/archive"; mkdir -p "$ARCH"
SID="${CLAUDE_CODE_SESSION_ID:-}"
# GC: sweep any active-dir snapshot older than 7 days into archive/ (bounded active dir)
find "$SNAP_DIR" -maxdepth 1 -type f -name '*.md' -mtime +7 -exec mv {} "$ARCH/" \; -printf 'GC-archived stale snapshot: %f\n' 2>/dev/null || true
# Archive THIS session's consumed snapshot (default path only — see note)
[ -n "$SID" ] && [ -f "$SNAP_DIR/$SID.md" ] && mv "$SNAP_DIR/$SID.md" "$ARCH/" && echo "archived consumed snapshot: $SID.md"

Under --no-commit: run the GC line but skip the $SID.md move (the handoff edit was not committed, so the snapshot must stay active as the fidelity source until a real checkpoint captures it). If Step 1b found no snapshot for this session, the $SID.md line is a no-op — nothing to archive.

Step 6 — Report

Print this structured summary to the user (NOT just the assistant log — actual user-facing report):

=== CHECKPOINT REPORT — <ISO_DATETIME> ===

Handoff fragment:     <path under docs/handoffs/rolling/>
Workboard fragment:   <path under .claude/workboard.d/>
Derived render:       local only (CURRENT-HANDOFF + workboard re-rendered; not committed)
Commit:               <#N merged to .jv test | committed locally <branch> | --no-commit: left unstaged for owner>

TRACKING SURFACES (6)
  [PASS|FAIL]  doc-locations-check.ts
  [PASS|WARN]  workboard-check.js
  [FRESH|...]  master-handoff-staleness.js
  [PASS|FAIL]  lanes-check.js
  [PASS|FAIL]  m1-adr-tracking-check.ts
  [PASS|FAIL]  m1-frontmatter-staleness-check.ts

INVENTORY
  active branches (branches.json):    <N>
  open PRs across fleet:              <N>
  active lanes:                       <N>
  uncommitted .jv changes:            <N files>

HOTFIXES → DURABLE (GAP-405, read-only; prefer durable fixes)
  [NONE|N pending]  revealui-harnesses hotfix check
  <for each pending: id — title — durable one-liner — resolve command>

PREPARE-FOR-EXIT (7, read-only, report-only)
  [PASS|WARN]  1. Fleet repo checkouts (main checkout) clean
  [PASS|WARN]  2. No worktree created this session remains
  [PASS|WARN]  3. No unpushed commits on any branch
  [PASS|WARN]  4. Registered temp scripts confirmed or surfaced
  [PASS|WARN]  5. Memory files created this session are indexed in MEMORY.md
  [PASS|WARN]  6. Handoff/workboard **fragments** committed and pushed (derived render optional/local)
  [PASS|WARN]  7. Scratchpad files that look like owner-run helpers are flagged
  <under each WARN, the verifier's own remediation line>

OUTSTANDING (action by owner or next agent)
  - <enumerate each FAIL item with suggested fix>
  - <enumerate uncommitted/unpushed work>
  - <enumerate owner-gated items>
  - <enumerate each PREPARE-FOR-EXIT WARN with its remediation line>
  - <enumerate each pending hotfix id + durable target (from Step 3f); never omit>

CHECKPOINT-READY: <YES | NO — see outstanding>

CHECKPOINT-READY rules:

• YES only when: all 6 validators PASS (or only master-handoff-staleness is STALE which is non-blocking) AND uncommitted .jv changes are zero (or explicitly peer-WIP untracked files only) AND every open PR for the active branches is either GREEN-AND-MERGEABLE or owner-gated.
• NO otherwise. Owner must address outstanding items before letting the session close.
• PREPARE-FOR-EXIT WARNs do NOT gate CHECKPOINT-READY — the verifier is report-only by design (it can never fail, per prepare-for-exit.js's own contract). List its WARNs under OUTSTANDING for visibility; do not flip YES to NO on their account alone.

Step 7 — Optionally notify daemon

If the RPC daemon is up (ss_daemon_alive) and nc is installed, post a checkpoint event (advisory — not required):

DAEMON_NOTIFIED="no"
DAEMON_NOTIFY_REASON=""
if ! command -v nc >/dev/null 2>&1; then
  DAEMON_NOTIFY_REASON="nc-missing"
elif [ ! -S "$DAEMON_SOCKET" ]; then
  DAEMON_NOTIFY_REASON="socket-absent"
elif ! command -v jq >/dev/null 2>&1; then
  DAEMON_NOTIFY_REASON="jq-missing"
else
  PAYLOAD="$(jq -cn --arg file "$CURRENT_HANDOFF" --arg from "$IDENTITY" \
    '{type:"checkpoint", file:$file, from:$from}')"
  if printf '%s\n' "$PAYLOAD" | nc -U -w 1 "$DAEMON_SOCKET" >/dev/null 2>&1; then
    DAEMON_NOTIFIED="yes"
  else
    DAEMON_NOTIFY_REASON="nc-write-failed"
  fi
fi

Daemon notification is non-blocking. If it fails for any reason, the handoff is still valid: next session's SessionStart hook discovers it via filesystem — session-start.js prints the [menu] CURRENT-HANDOFF §Ordered next actions pointer whenever the rolling handoff exists, which is the next-session orientation surface. (The former Step 7.5 invoked a session-note skill that was never built; removed in 0.6.1.)

Step 8 — Emit copy-pasteable next-agent prompt (LAST output — nothing after this)

Per ~/.claude/rules/coordination.md §"Archive-Readiness Convention" (2026-05-11): the final output of any checkpoint flow MUST be a copy-pasteable "next-agent prompt" the owner can drop straight into a new Claude Code session — no synthesis required, no jumping between docs. The prompt is non-negotiable. Without it, the owner has to do friction work (read CURRENT-HANDOFF.md + workboard + memories + figure out the first action) every multi-session handoff. That friction compounds across the fleet.

Compose the prompt with these 5 sections (in order):

1. First line — Session <session-id> — read first: $JV_REPO/docs/handoffs/CURRENT-HANDOFF.md. The path is the absolute filesystem path to the rolling handoff file.
2. TL;DR — 1–2 sentences with the single most important next action. Mirror §"Ordered next actions" item 1 from CURRENT-HANDOFF.md; do not re-summarize.
3. Ordered next-actions — numbered list with EXACT commands / values / file paths. No "investigate X" / "decide Y" / "look into Z" — those belong in CURRENT-HANDOFF.md body. Pre-resolve every path, hash, branch name, PR number. If the next-agent has to fill in <paste prod URL here>, the convention has been violated.
4. Locked-posture reminder — one line. HARDLINES: core.fileMode=false on every .jv commit; fragments-only pathspec (rolling + workboard.d, never derived CURRENT-HANDOFF/workboard); -F /tmp/cmsg-*.txt; --body-file; --head/--base explicit; gh pr merge --merge only on revealui-jv (label merge:merge-commit); no --auto/--no-verify/--admin/--force-push/--squash; audit-first; no authored regex; revvault-first secrets; durable-only.
5. Owner-gated deferrals — one short list of items the next agent must NOT auto-pick up without explicit owner sign-off.

Emit the prompt wrapped in a single triple-backtick fenced code block. The block must be the LAST thing emitted in the turn — no commentary, no "and that's it" trailer, nothing.

If the Step 6 verdict is CHECKPOINT-READY: NO, the TL;DR must lead with BLOCKED: <reason>. Resolve before next session. and the NEXT ACTIONS list must enumerate the blockers (failed validators, uncommitted state, open PRs without owner-gate clearance) as items to clear first.

If the session was a no-op (nothing shipped, no in-flight work), still emit the prompt — TL;DR reads SESSION END — no follow-up required. Next agent starts fresh. and NEXT ACTIONS list is empty (the section header still appears for symmetry).

The same content should be in CURRENT-HANDOFF.md §"Next-agent prompt" (optional Step 4 section). The chat emission is for immediate copy-paste; CURRENT-HANDOFF.md is for recovery if chat closes before paste.

Do not

• Do NOT emit ANY text or tool call after Step 8's fenced prompt block. The block is the last thing in the turn — the owner triple-clicks to select.
• Do NOT auto-commit on the MAIN .jv checkout — committing there strands it on a chore/checkpoint-* branch (the 8-session divergence bug). Commit ONLY via Step 5b (worktree-gated when a peer is live), or pass --no-commit to defer to the owner. Still NEVER auto-merge with --admin or squash.
• Do NOT commit docs/handoffs/CURRENT-HANDOFF.md or .claude/workboard.md in a session checkpoint PR (derived renders; ADR 2026-07-23). Commit fragments only.
• Do NOT run master-handoff-regen.js — that's a separate audited operation (agent-invoked, owner-attended, expensive).
• Do NOT create dated standalone handoff files (docs/HANDOFF-YYYY-MM-DD-*.md) — the rolling CURRENT-HANDOFF.md is the target. Do NOT write to $JV_REPO/.claude/handoffs/ (non-canonical, retired 2026-05-19).
• Do NOT write to /tmp/agent-handoff-*.md (orphaned by design).
• Do NOT move or delete handoff files — the 7-day sweep handles dated files; the CURRENT-HANDOFF.md prune (Step 4b) handles the rolling file.
• Do NOT modify lane plans or MASTER_PLAN.md — validators here are READ-ONLY against body content.
• Do NOT reference tmux, tmux windows, panes, or TMUX_PANE — Studio-native.
• Do NOT attempt to spawn a new agent process — the user (or Studio UI) controls session creation.

When to invoke

• End of a meaningful session (something shipped that needs handoff).
• Before a planned absence (owner stepping away mid-flight).
• When the user types /checkpoint, /checkpoint <topic>, or the Stop hook decides to run a final check.
• NOT for one-off questions, read-only sessions, or aborted starts.

Arguments: /checkpoint --no-commit skips Step 5b and leaves fragment writes UNSTAGED for the owner to review/commit — use it when the handoff needs an eyeball before it lands. The default (no flag) commits + converges fragments only to .jv test per Step 5b (merge-commit; label merge:merge-commit).

Relationship to /handoff

/handoff is the predecessor — writes a basic handoff doc to the (now non-canonical) .claude/handoffs/ location with no tracking-surface validation. /checkpoint supersedes it: rolling fragments + local CURRENT-HANDOFF render + 6 validators + inventory + structured report. Recommend the slash command symlink at ~/.claude/commands/handoff.md be retargeted to this skill in a follow-up (separate revskills PR).

Related ADRs (.jv)

• docs/decisions/2026-07-23-jv-coordination-merge-model.md — fragments-only PRs; concurrent land-as-ready
• docs/decisions/2026-07-23-jv-merge-commit-only.md — merge-commit policy + label
• docs/decisions/2026-07-21-current-handoff-rolling-fragments.md — rolling fragments (amended)
• docs/decisions/2026-07-04-workboard-fragment-store.md — workboard.d fragments