diff --git a/.github/labels.json b/.github/labels.json
index 628380ba7..f6bc13f5b 100644
--- a/.github/labels.json
+++ b/.github/labels.json
@@ -58,5 +58,10 @@
     "name": "risk:T3",
     "color": "D93F0B",
     "description": "T3 (PASS at the tip, green CI). Advisory; the controller labels it, the merge gate recomputes it"
+  },
+  {
+    "name": "pass",
+    "color": "006B75",
+    "description": "Reviewer PASS verdict at the merged head; set by pass-label, never removed"
   }
 ]
diff --git a/.github/scripts/pass-label.mjs b/.github/scripts/pass-label.mjs
new file mode 100644
index 000000000..3895c5340
--- /dev/null
+++ b/.github/scripts/pass-label.mjs
@@ -0,0 +1,132 @@
+// The `pass` label: a pull request that carried a PASS verdict while it merged keeps a visible trace
+// of it (#739). The verdict itself lives only in a comment thread, and `agent-pr` says nothing about
+// whether anything was reviewed.
+//
+//   node .github/scripts/pass-label.mjs --comment     # one new comment: label the PR when it is a PASS
+//   node .github/scripts/pass-label.mjs --backfill    # merged pull requests whose head carried a PASS
+//
+// Both paths read the verdict with `parseReport`, the parser `review-gate.mjs` and `merge-gate.mjs`
+// already use, so the fixed format (`Verdict: PASS at <sha>` first line, `Written-by:` second) is read
+// the same way everywhere. Three rules keep this a record and not a gate:
+//   - only a conclusion from someone GitHub ties to this repository counts (`OWNER`, `MEMBER`,
+//     `COLLABORATOR`), and only when its `Written-by:` names someone in the policy's `writers` (#676);
+//   - a `Correction from …` comment never labels, because it is text about a conclusion, not one —
+//     `parseReport` would happily find the `Verdict:` it quotes;
+//   - the label is only ever added. A later INC or a moved tip does not remove it: it records that a
+//     PASS was given, and `hold` stays the one manual stop.
+import { execFileSync } from 'node:child_process'
+import { readFileSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
+import { parseReport, loadPolicy } from './review-gate.mjs'
+
+export const PASS_LABEL = 'pass'
+export const ASSOCIATIONS = new Set(['OWNER', 'MEMBER', 'COLLABORATOR'])
+const POLICY = '.github/agent/review-policy.json'
+const SHORT = 12
+
+const firstLine = (body) => String(body ?? '').split('\n').map((line) => line.trim()).find((line) => line !== '') ?? ''
+
+// Does this body decide that the tip was PASSed? `Correction from …` never does, whatever it quotes.
+export function verdictOf(body, { writers = [], association } = {}) {
+  if (!ASSOCIATIONS.has(String(association ?? '').toUpperCase())) return null
+  if (/^Correction\b/i.test(firstLine(body))) return null
+  const report = parseReport(body)
+  if (report.verdict !== 'PASS') return null
+  if (!report.writer || !writers.includes(report.writer)) return null
+  return report
+}
+
+// A report and the head it names: the tip may be a prefix (a 12-character sha is the usual form).
+export function namesHead(tip, head) {
+  if (!tip || !head) return false
+  const t = String(tip).toLowerCase()
+  const h = String(head).toLowerCase()
+  return h.startsWith(t) || t.startsWith(h.slice(0, t.length))
+}
+
+// One comment (a comment event's payload) decides for one pull request.
+export function planComment({ pr, body, association, writers, labels = [] }) {
+  const report = verdictOf(body, { writers, association })
+  if (!report) return { add: false, reason: 'not a PASS by a writer the policy lists' }
+  if (labels.map((l) => String(l.name ?? l).toLowerCase()).includes(PASS_LABEL)) return { add: false, reason: `already labelled ${PASS_LABEL}` }
+  return { add: true, pr, tip: report.tip }
+}
+
+// Merged pull requests whose history carries a PASS at the head that merged, and which do not have the
+// label yet. `pages` is the raw API data so the whole decision is testable without the network.
+export function planBackfill({ pulls, historyOf, writers }) {
+  const items = []
+  for (const pull of pulls) {
+    if (!pull.merged_at) continue
+    const labels = (pull.labels ?? []).map((l) => String(l.name ?? l).toLowerCase())
+    if (labels.includes(PASS_LABEL)) continue
+    const head = pull.head?.sha
+    if (!head) continue
+    const history = historyOf(pull.number) ?? []
+    const pass = history
+      .filter((entry) => entry.body && (entry.association ? ASSOCIATIONS.has(String(entry.association).toUpperCase()) : true))
+      .map((entry) => ({ at: entry.at ?? '', report: verdictOf(entry.body, { writers, association: entry.association ?? 'MEMBER' }) }))
+      .filter((entry) => entry.report && namesHead(entry.report.tip, head))
+      .sort((a, b) => String(a.at).localeCompare(String(b.at)))
+      .pop()
+    if (pass) items.push({ number: pull.number, title: pull.title ?? '', tip: pass.report.tip })
+  }
+  return items.sort((a, b) => a.number - b.number)
+}
+
+const realGh = (...a) => execFileSync('gh', a, { encoding: 'utf8', maxBuffer: 16 << 20 })
+const list = (gh, path) => {
+  const out = gh('api', '--paginate', '--jq', '.[]', path)
+  return String(out ?? '').split('\n').filter(Boolean).map((line) => JSON.parse(line))
+}
+
+// The history of one pull request: its comments and its review bodies, oldest first. A conclusion the
+// reviewer wrote as a review counts the same as a comment.
+export function historyFrom({ comments = [], reviews = [] }) {
+  const rows = [
+    ...comments.map((c) => ({ body: c.body, association: c.author_association, at: c.created_at })),
+    ...reviews.filter((r) => r.body).map((r) => ({ body: r.body, association: r.author_association, at: r.submitted_at })),
+  ]
+  return rows.sort((a, b) => String(a.at ?? '').localeCompare(String(b.at ?? '')))
+}
+
+export function main({ gh = realGh, env = process.env } = {}) {
+  const repo = env.GH_REPO
+  if (!repo) throw new Error('set GH_REPO')
+  const writers = loadPolicy(POLICY).writers ?? []
+  const add = (pr) => gh('api', '-X', 'POST', `repos/${repo}/issues/${pr}/labels`, '-f', `labels[]=${PASS_LABEL}`)
+
+  if (process.argv.includes('--comment')) {
+    const pr = Number(env.PR)
+    if (!pr) throw new Error('set PR')
+    const plan = planComment({ pr, body: env.COMMENT_BODY ?? '', association: env.ASSOCIATION, writers })
+    if (!plan.add) {
+      console.log(`pass-label: #${pr} not labelled — ${plan.reason}`)
+      return { ok: true, added: [] }
+    }
+    add(pr)
+    console.log(`pass-label: #${pr} labelled ${PASS_LABEL} (PASS at ${plan.tip})`)
+    return { ok: true, added: [pr] }
+  }
+
+  if (process.argv.includes('--backfill')) {
+    const pulls = list(gh, `repos/${repo}/pulls?state=closed&sort=updated&direction=desc&per_page=100`)
+    const historyOf = (number) => historyFrom({
+      comments: list(gh, `repos/${repo}/issues/${number}/comments?per_page=100`),
+      reviews: list(gh, `repos/${repo}/pulls/${number}/reviews?per_page=100`),
+    })
+    const items = planBackfill({ pulls, historyOf, writers })
+    console.log(`pass-label: backfill: ${items.length} merged pull request(s) carry a PASS at their head and no ${PASS_LABEL}`)
+    for (const item of items) {
+      console.log(`#${item.number} ${item.title} (PASS at ${String(item.tip).slice(0, SHORT)})`)
+      add(item.number)
+    }
+    return { ok: true, added: items.map((item) => item.number) }
+  }
+
+  throw new Error('pass --comment or --backfill')
+}
+
+if (process.argv[1] === fileURLToPath(import.meta.url)) {
+  try { main() } catch (error) { console.error(`pass-label: ${error.message}`); process.exit(1) }
+}
diff --git a/.github/scripts/pass-label.test.mjs b/.github/scripts/pass-label.test.mjs
new file mode 100644
index 000000000..b4f7ad917
--- /dev/null
+++ b/.github/scripts/pass-label.test.mjs
@@ -0,0 +1,91 @@
+// The `pass` label (#739): a verdict that let a pull request in leaves a visible mark, mechanically.
+// The parser is the one the gates already use, so these cases pin the three rules that decide it —
+// who may write a conclusion, what a correction is, and that the label is only ever added.
+import { test } from 'node:test'
+import assert from 'node:assert/strict'
+import { readFileSync } from 'node:fs'
+import { join } from 'node:path'
+import { PASS_LABEL, namesHead, planBackfill, planComment, verdictOf, historyFrom } from './pass-label.mjs'
+import { loadPolicy } from './review-gate.mjs'
+
+const repo = join(import.meta.dirname, '..', '..')
+const writers = loadPolicy(join(repo, '.github/agent/review-policy.json')).writers
+const head = 'df5d6f7e2b1c4f7a9e0d3c5b8a1f2e4d6c8b0a13'
+
+const conclusion = (verdict = 'PASS', sha = head, writer = 'Reviewer') => `Verdict: ${verdict} at ${sha}
+Written-by: ${writer}
+
+## What I ran
+- \`cd core && npm test\` → 1239/1239
+
+## Risk
+T1.`
+
+test('#739: a PASS at the tip labels the pull request', () => {
+  const plan = planComment({ pr: 7, body: conclusion(), association: 'MEMBER', writers })
+  assert.equal(plan.add, true)
+  assert.equal(plan.tip, head)
+})
+
+test('#739: an INC, a correction, a non-member and an unknown writer never label', () => {
+  assert.equal(verdictOf(conclusion('INC'), { writers, association: 'MEMBER' }), null)
+  const correction = `Correction from Reviewer: the PASS at ${head} listed no command it ran.
+
+Verdict: PASS at ${head}
+Written-by: Reviewer`
+  assert.equal(verdictOf(correction, { writers, association: 'MEMBER' }), null, 'a correction is text about a conclusion')
+  assert.equal(verdictOf(conclusion(), { writers, association: 'NONE' }), null, 'a passer-by is not a conclusion')
+  assert.equal(verdictOf(conclusion('PASS', head, 'Stranger'), { writers, association: 'MEMBER' }), null, 'the name must be in writers')
+})
+
+test('#739: a replacement PASS labels like a normal PASS, and a second run adds nothing', () => {
+  const replacement = `Verdict: PASS at ${head}
+Written-by: Reviewer
+Replaces: the PASS at ${head} merge-gate rejected for having no Ran: line
+
+## What I ran
+- \`node --test test/follow-through.test.js\` → 14/14`
+  assert.ok(verdictOf(replacement, { writers, association: 'OWNER' }))
+  const already = planComment({ pr: 7, body: conclusion(), association: 'MEMBER', writers, labels: [{ name: PASS_LABEL }, { name: 'agent-pr' }] })
+  assert.equal(already.add, false)
+  assert.match(already.reason, /already labelled/)
+})
+
+test('#739: backfill labels a merged pull request whose head carried a PASS, and nothing else', () => {
+  const pulls = [
+    { number: 11, title: 'merged on a PASS', merged_at: '2026-10-22T10:00:00Z', head: { sha: head }, labels: [{ name: 'agent-pr' }] },
+    { number: 12, title: 'merged on an INC', merged_at: '2026-10-22T10:05:00Z', head: { sha: head }, labels: [] },
+    { number: 13, title: 'already labelled', merged_at: '2026-10-22T10:10:00Z', head: { sha: head }, labels: [{ name: PASS_LABEL }] },
+    { number: 14, title: 'still open', merged_at: null, head: { sha: head }, labels: [] },
+    // A PASS about some other tip is not a PASS about the head that merged.
+    { number: 15, title: 'PASS at another tip', merged_at: '2026-10-22T10:20:00Z', head: { sha: head }, labels: [] },
+  ]
+  const history = {
+    11: historyFrom({ comments: [{ body: conclusion(), author_association: 'MEMBER', created_at: '2026-10-22T09:00:00Z' }] }),
+    12: historyFrom({ comments: [{ body: conclusion('INC'), author_association: 'MEMBER', created_at: '2026-10-22T09:00:00Z' }] }),
+    13: historyFrom({ comments: [{ body: conclusion(), author_association: 'MEMBER', created_at: '2026-10-22T09:00:00Z' }] }),
+    14: historyFrom({ comments: [{ body: conclusion(), author_association: 'MEMBER', created_at: '2026-10-22T09:00:00Z' }] }),
+    15: historyFrom({ comments: [{ body: conclusion('PASS', 'aaaaaaaaaaaa'), author_association: 'MEMBER', created_at: '2026-10-22T09:00:00Z' }] }),
+  }
+  const items = planBackfill({ pulls, historyOf: (n) => history[n], writers })
+  assert.deepEqual(items.map((item) => item.number), [11])
+  // Second run: the label added by the first run is what the API now reports, so nothing is planned.
+  const after = planBackfill({ pulls: pulls.map((p) => (p.number === 11 ? { ...p, labels: [{ name: PASS_LABEL }] } : p)), historyOf: (n) => history[n], writers })
+  assert.deepEqual(after, [])
+})
+
+test('#739: a review body counts like a comment, and the label is a closed record', () => {
+  const history = historyFrom({ reviews: [{ body: conclusion(), author_association: 'COLLABORATOR', submitted_at: '2026-10-22T09:30:00Z' }] })
+  assert.equal(history.length, 1)
+  assert.ok(verdictOf(history[0].body, { writers, association: history[0].association }))
+  // No path removes the label: only `add` lines exist in the script.
+  const source = readFileSync(join(repo, '.github/scripts/pass-label.mjs'), 'utf8')
+  assert.doesNotMatch(source, /-X\s+'?\s*DELETE|method:\s*'DELETE'/)
+})
+
+test('#739: a 12-character tip names the head, a different one does not', () => {
+  assert.equal(namesHead(head.slice(0, 12), head), true)
+  assert.equal(namesHead(head, head.slice(0, 12)), true)
+  assert.equal(namesHead('aaaaaaaaaaaa', head), false)
+  assert.equal(namesHead(null, head), false)
+})
diff --git a/.github/scripts/sync-labels.test.mjs b/.github/scripts/sync-labels.test.mjs
index 38c7ab713..0c0ebf9cb 100644
--- a/.github/scripts/sync-labels.test.mjs
+++ b/.github/scripts/sync-labels.test.mjs
@@ -15,13 +15,14 @@ test('plan: create missing, keep equal, update changed, ignore others', () => {
 
 test('labels.json: valid, unique, agent-ready is the approval label', () => {
   const names = wanted.map((l) => l.name.toLowerCase())
-  assert.equal(wanted.length, 12, 'the 12 live labels (#702: the retired approval label is not one of them)')
+  // #702 retired the approval label; #739 added `pass`, which records that a verdict was a PASS.
+  assert.equal(wanted.length, 13, 'the 13 live labels')
   assert.equal(new Set(names).size, names.length)
   for (const l of wanted) {
     assert.match(l.color, /^[0-9A-F]{6}$/i)
     assert.ok(l.description.length > 0 && l.description.length <= 100, l.name)
   }
-  for (const n of ['agent-task', 'agent-ready', 'agent-working', 'agent-pr', 'self-test', 'needs-human', 'hold']) assert.ok(names.includes(n), n)
+  for (const n of ['agent-task', 'agent-ready', 'agent-working', 'agent-pr', 'self-test', 'needs-human', 'hold', 'pass']) assert.ok(names.includes(n), n)
 })
 
 test('the agent-task form never applies agent-ready', () => {
diff --git a/.github/workflows/pass-label.yml b/.github/workflows/pass-label.yml
new file mode 100644
index 000000000..cb8b1a788
--- /dev/null
+++ b/.github/workflows/pass-label.yml
@@ -0,0 +1,62 @@
+name: Pass label
+
+# A merged pull request kept no trace of the verdict that let it in: `agent-pr` stays, and the PASS
+# lives only in a comment thread (#739). This labels a pull request `pass` when a `Verdict: PASS at
+# <sha>` conclusion is posted, and backfills the merged ones on demand.
+#
+# It is a record, not a gate. It only ever adds the label — a later INC, a moved tip or a `hold` never
+# removes it — and it reads the conclusion with the same parser the gates use, so a comment from
+# outside the repository, a `Written-by:` name the policy does not list and a `Correction from …`
+# comment all leave the pull request alone.
+on:
+  issue_comment:
+    types: [created]
+  workflow_dispatch:
+    inputs:
+      backfill:
+        description: 'Label every merged pull request whose head carried a PASS'
+        type: boolean
+        default: true
+
+concurrency:
+  group: pass-label-${{ github.event.issue.number || 'backfill' }}
+  cancel-in-progress: false
+
+permissions:
+  contents: read
+  issues: write
+  pull-requests: write
+
+jobs:
+  label:
+    name: pass label
+    # A comment on a plain issue is not a pull request; a manual run is the backfill.
+    if: github.event_name == 'workflow_dispatch' || github.event.issue.pull_request != null
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          ref: main
+          persist-credentials: false
+      - uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1  # v7.1.0
+        with:
+          node-version: 24
+      # The comment body is untrusted text: it is only parsed, never run, and the label is added from
+      # base-branch code. `pull_request` on a comment would run PR code, so this stays an
+      # `issue_comment` workflow.
+      - name: Label the pull request a PASS conclusion was posted on
+        if: github.event_name == 'issue_comment'
+        env:
+          GH_TOKEN: ${{ github.token }}
+          GH_REPO: ${{ github.repository }}
+          PR: ${{ github.event.issue.number }}
+          COMMENT_BODY: ${{ github.event.comment.body }}
+          ASSOCIATION: ${{ github.event.comment.author_association }}
+        run: node .github/scripts/pass-label.mjs --comment
+      - name: Backfill merged pull requests whose head carried a PASS
+        if: github.event_name == 'workflow_dispatch'
+        env:
+          GH_TOKEN: ${{ github.token }}
+          GH_REPO: ${{ github.repository }}
+        run: node .github/scripts/pass-label.mjs --backfill
diff --git a/docs/testing-layers.json b/docs/testing-layers.json
index 61c206bc8..d717623b8 100644
--- a/docs/testing-layers.json
+++ b/docs/testing-layers.json
@@ -201,6 +201,15 @@
       "layer": "none",
       "gate": false,
       "reason": "The mechanical release: preflight, release PR, tag. It runs no tests of its own."
+    },
+    {
+      "id": "pass-label",
+      "workflow": ".github/workflows/pass-label.yml",
+      "kind": "workflow-only",
+      "layer": "none",
+      "gate": false,
+      "runs": "issue_comment (created) and workflow_dispatch",
+      "reason": "Applies the `pass` label to a pull request whose conclusion was a PASS, and backfills merged ones (#739). A workflow-only layer with no test file of its own, and it gates nothing."
     }
   ]
 }
diff --git a/docs/testing-layers.md b/docs/testing-layers.md
index 7ea67fe8c..8b6fcd516 100644
--- a/docs/testing-layers.md
+++ b/docs/testing-layers.md
@@ -100,5 +100,6 @@ The tables below are generated: edit `docs/testing-layers.json`, then run
 | `label-hygiene.yml` | workflow-only | none | no | daily 03:30 Asia/Shanghai, and workflow_dispatch | Scheduled cleanup of status labels on closed issues and pull requests (#738). A workflow-only layer with no test file of its own, and it gates nothing. |
 | `nightly.yml` | workflow-only | none | no | daily 00:00 Asia/Shanghai, Sunday 01:00 compat matrix, and workflow_dispatch | The compatibility matrix (other OS, Node and DSH versions) on a schedule. It widens coverage but is not a gate, and its cases are not part of L1 or L2. |
 | `release.yml` | not-a-layer | none | no | — | The mechanical release: preflight, release PR, tag. It runs no tests of its own. |
+| `pass-label.yml` | workflow-only | none | no | issue_comment (created) and workflow_dispatch | Applies the `pass` label to a pull request whose conclusion was a PASS, and backfills merged ones (#739). A workflow-only layer with no test file of its own, and it gates nothing. |
 
 <!-- generated:testing-layers:end -->