diff --git a/.github/workflows/agent-pr-ready-automerge.yml b/.github/workflows/agent-pr-ready-automerge.yml
index 82470666..78840bd7 100644
--- a/.github/workflows/agent-pr-ready-automerge.yml
+++ b/.github/workflows/agent-pr-ready-automerge.yml
@@ -5,6 +5,8 @@
 # non-`cursor/*` branches are never touched — the draft flag is the actor's
 # veto (the CLI skips them). Fork PRs are excluded (the repo is public; a
 # merged fork PR would deploy) — same RCE-guard class as the other workflows.
+# OPS98: `audit/*` branches (engineering-audit overnight run) are also skipped —
+# that single Ready PR merges by human hand only.
 #
 # GitHub's NATIVE auto-merge replaces the Forgejo-era poll CLI (removed in
 # OPS71 Fase 2): `enablePullRequestAutoMerge` (GraphQL, REBASE —
diff --git a/scripts/github-pr-automerge.mjs b/scripts/github-pr-automerge.mjs
index a7828184..ee6b983a 100644
--- a/scripts/github-pr-automerge.mjs
+++ b/scripts/github-pr-automerge.mjs
@@ -13,7 +13,9 @@
  * mergeable. The OPS64 "never trust the rollup" pin is structural here: a
  * single sequential job posts one honest check-run, and the server enforces
  * it. Draft policy (OPS57) preserved: only `cursor/*` heads are marked
- * ready — any other draft is the actor's veto (skip, exit 0).
+ * ready — any other draft is the actor's veto (skip, exit 0). OPS98: `audit/*`
+ * heads are vetoed entirely (ready or draft) — the engineering-audit single PR
+ * merges by human hand only.
  *
  * Idempotent: already merged / closed / non-main base → no-op success.
  * A GraphQL error (e.g. repo auto-merge disabled, PR in conflict) exits 1 so
diff --git a/scripts/lib/github-pr-flow.mjs b/scripts/lib/github-pr-flow.mjs
index 17823876..f8ac8857 100644
--- a/scripts/lib/github-pr-flow.mjs
+++ b/scripts/lib/github-pr-flow.mjs
@@ -6,7 +6,8 @@
  *
  * GitHub's native auto-merge only fires with the required checks green, so
  * the safety net's only real decisions are: skip (non-main base, draft veto,
- * already merged) or mark-ready (cursor/* draft) before arming auto-merge.
+ * already merged, audit/* veto) or mark-ready (cursor/* draft) before arming
+ * auto-merge.
  */
 
 export const CURSOR_HEAD_PREFIX = 'cursor/'
@@ -14,6 +15,15 @@ export const CURSOR_HEAD_PREFIX = 'cursor/'
 /** OPS57: only `cursor/*` drafts get force-marked ready — any other draft is the actor's veto. */
 export const isCursorHead = (ref) => typeof ref === 'string' && ref.startsWith(CURSOR_HEAD_PREFIX)
 
+/**
+ * OPS98: branches `audit/*` belong to the engineering-audit overnight run —
+ * its single PR must stay Ready WITHOUT auto-merge (the human is the final
+ * gate). The veto is dominant: it applies to ready and draft states alike.
+ */
+export const AUDIT_HEAD_PREFIX = 'audit/'
+
+export const isAuditHead = (ref) => typeof ref === 'string' && ref.startsWith(AUDIT_HEAD_PREFIX)
+
 /**
  * OPS71-FLIP: the auto-merge MUST be armed with a real user PAT. Arming with
  * the built-in GITHUB_TOKEN makes the merge happen as `github-actions[bot]`,
@@ -41,6 +51,7 @@ export const automergeArmingToken = (env = process.env) => {
  */
 export const decideAutomergeAction = (pr) => {
   if (!pr) return { action: 'skip', reason: 'pr-inexistente' }
+  if (isAuditHead(pr.head?.ref)) return { action: 'skip', reason: 'audit-veto' }
   if (pr.merged) return { action: 'skip', reason: 'ja-mergeada' }
   if (pr.state !== 'OPEN') return { action: 'skip', reason: 'pr-nao-aberta' }
   if (pr.base?.ref !== 'main') return { action: 'skip', reason: 'base-nao-main' }
diff --git a/tests/unit/githubPrFlow.unit.spec.ts b/tests/unit/githubPrFlow.unit.spec.ts
index 66b889e4..4b684d91 100644
--- a/tests/unit/githubPrFlow.unit.spec.ts
+++ b/tests/unit/githubPrFlow.unit.spec.ts
@@ -1,9 +1,11 @@
 import { describe, expect, it } from 'vitest'
 
 import {
+  AUDIT_HEAD_PREFIX,
   CURSOR_HEAD_PREFIX,
   automergeArmingToken,
   decideAutomergeAction,
+  isAuditHead,
   isCursorHead,
 } from '../../scripts/lib/github-pr-flow.mjs'
 
@@ -66,6 +68,29 @@ describe('github-pr-flow automerge decision (OPS71)', () => {
     expect(isCursorHead(undefined)).toBe(false)
   })
 
+  it('skips a ready audit/* PR — the single-PR overnight delivery (OPS98)', () => {
+    const verdict = decideAutomergeAction(
+      pr({ head: { ref: `${AUDIT_HEAD_PREFIX}pass-6`, sha: 'abc' } }),
+    )
+    expect(verdict).toEqual({ action: 'skip', reason: 'audit-veto' })
+  })
+
+  it('audit/* veto dominates the draft logic — a draft audit/* never becomes mark-ready', () => {
+    const verdict = decideAutomergeAction(
+      pr({ draft: true, head: { ref: `${AUDIT_HEAD_PREFIX}pass-6`, sha: 'abc' } }),
+    )
+    expect(verdict).toEqual({ action: 'skip', reason: 'audit-veto' })
+  })
+
+  it('isAuditHead only matches the exact audit/ prefix', () => {
+    expect(isAuditHead('audit/pass-6')).toBe(true)
+    expect(isAuditHead('OPS71-x')).toBe(false)
+    expect(isAuditHead('cursor/x')).toBe(false)
+    expect(isAuditHead('auditoria/x')).toBe(false)
+    expect(isAuditHead('')).toBe(false)
+    expect(isAuditHead(undefined)).toBe(false)
+  })
+
   it('the merge contract has no poll path: ready always arms native auto-merge', () => {
     // OPS64 pin, GitHub shape: the Forgejo rollup-lie bug is structural here
     // (single job → one honest check-run), and the server only merges with
@@ -73,8 +98,9 @@ describe('github-pr-flow automerge decision (OPS71)', () => {
     const actions = [
       decideAutomergeAction(pr()).action,
       decideAutomergeAction(pr({ draft: true, head: { ref: 'cursor/x', sha: 'a' } })).action,
+      decideAutomergeAction(pr({ head: { ref: 'audit/pass-6', sha: 'a' } })).action,
     ]
-    expect(actions).toEqual(['enable-auto-merge', 'mark-ready'])
+    expect(actions).toEqual(['enable-auto-merge', 'mark-ready', 'skip'])
   })
 
   it('automergeArmingToken accepts a non-empty AUTOMERGE_PAT (OPS71-FLIP)', () => {