diff --git a/.github/workflows/cli-release-check.yml b/.github/workflows/cli-release-check.yml
index a949ad91..189623a0 100644
--- a/.github/workflows/cli-release-check.yml
+++ b/.github/workflows/cli-release-check.yml
@@ -11,6 +11,7 @@ on:
       - ".github/workflows/release.yml"
       - ".github/scripts/openprose-smoke/**"
       - "scripts/release-preflight.sh"
+      - "scripts/pr-preflight.sh"
       - "scripts/bump-version.sh"
       - ".version-bump.json"
   push:
@@ -25,6 +26,7 @@ on:
       - ".github/workflows/release.yml"
       - ".github/scripts/openprose-smoke/**"
       - "scripts/release-preflight.sh"
+      - "scripts/pr-preflight.sh"
       - "scripts/bump-version.sh"
       - ".version-bump.json"
   workflow_dispatch:
@@ -66,9 +68,13 @@ jobs:
       - name: Check harness smoke helper syntax
         run: node --check tools/cli/scripts/smoke-harness.mjs
 
+      - name: Check audit policy helper syntax
+        run: node --check tools/cli/scripts/audit-policy.mjs
+
       - name: Check release shell syntax
         run: |
           bash -n scripts/bump-version.sh
+          bash -n scripts/pr-preflight.sh
           bash -n scripts/release-preflight.sh
 
       - name: OpenProse versions in sync
diff --git a/AGENTS.md b/AGENTS.md
index 16917816..93c23fbd 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -7,3 +7,5 @@ Treat `prose run ...` as an instruction inside the current agent session. Do not
 Use `prose upgrade --dry-run` to preview legacy migrations and `prose upgrade` to apply them; do not recommend the old migrate command.
 
 Open `skills/open-prose/SKILL.md` and treat it as the authoritative router. Every command, every file routing decision, and every capability assumption lives there or behind a pointer inside it. Do not search the workspace for alternate copies of the OpenProse documentation — the canonical files are the ones bundled under `skills/open-prose/`.
+
+Before calling a PR mergeable or asking someone to review CI, run `./scripts/pr-preflight.sh` from a clean branch. It fetches `origin/main`, simulates merging the current HEAD into that base, and runs the local CI-equivalent checks. If you intentionally skip part of it, say exactly which part and why.
diff --git a/scripts/pr-preflight.sh b/scripts/pr-preflight.sh
new file mode 100755
index 00000000..586099a7
--- /dev/null
+++ b/scripts/pr-preflight.sh
@@ -0,0 +1,127 @@
+#!/usr/bin/env bash
+# Validate a PR branch against the current upstream base before pushing or merging.
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+
+base_ref="${OPENPROSE_PR_BASE_REF:-origin/main}"
+fetch_base=1
+run_smoke=1
+
+usage() {
+  cat >&2 <<'EOF'
+usage: ./scripts/pr-preflight.sh [options]
+
+Options:
+  --base REF        Base ref to merge against. Defaults to origin/main.
+  --no-fetch        Do not fetch origin/main before validating.
+  --no-smoke        Skip OpenProse smoke dry-run.
+EOF
+}
+
+fail() {
+  printf 'pr preflight: %s\n' "$*" >&2
+  exit 1
+}
+
+need_command() {
+  command -v "$1" >/dev/null 2>&1 || fail "required command not found: $1"
+}
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --base)
+      base_ref="${2:-}"
+      shift 2
+      ;;
+    --no-fetch)
+      fetch_base=0
+      shift
+      ;;
+    --no-smoke)
+      run_smoke=0
+      shift
+      ;;
+    -h|--help)
+      usage
+      exit 0
+      ;;
+    *)
+      usage
+      fail "unknown argument: $1"
+      ;;
+  esac
+done
+
+[[ -n "$base_ref" ]] || fail "--base must not be empty"
+
+need_command git
+need_command npm
+need_command node
+
+if ! node --help 2>&1 | grep -q -- '--check'; then
+  fail "node on PATH does not support --check; put Node.js before any compatibility shim on PATH"
+fi
+
+cd "$REPO_ROOT"
+
+if ! git diff --quiet; then
+  fail "tracked working tree changes are present; commit or stash them before preflight"
+fi
+
+if ! git diff --cached --quiet; then
+  fail "staged changes are present; commit or unstage them before preflight"
+fi
+
+if [[ "$fetch_base" -eq 1 ]]; then
+  git fetch origin main:refs/remotes/origin/main
+fi
+
+head_ref="$(git rev-parse --verify HEAD)"
+worktree="$(mktemp -d "${TMPDIR:-/tmp}/openprose-pr-preflight.XXXXXX")"
+
+cleanup() {
+  git -C "$REPO_ROOT" worktree remove --force "$worktree" >/dev/null 2>&1 || true
+}
+trap cleanup EXIT
+
+git worktree add --detach "$worktree" "$base_ref" >/dev/null
+git -C "$worktree" merge --no-commit --no-ff "$head_ref"
+
+cd "$worktree"
+
+git diff --check
+
+if command -v actionlint >/dev/null 2>&1; then
+  actionlint .github/workflows/cli-*.yml .github/workflows/plugin-manifest.yml .github/workflows/openprose-smoke.yml .github/workflows/release.yml
+elif command -v go >/dev/null 2>&1; then
+  go run github.com/rhysd/actionlint/cmd/actionlint@v1.7.7 .github/workflows/cli-*.yml .github/workflows/plugin-manifest.yml .github/workflows/openprose-smoke.yml .github/workflows/release.yml
+else
+  fail "actionlint or go is required for workflow linting"
+fi
+
+bash -n tools/cli/install.sh
+node --check tools/cli/scripts/build-release-tarball.mjs
+node --check tools/cli/scripts/smoke-harness.mjs
+node --check tools/cli/scripts/audit-policy.mjs
+bash -n scripts/bump-version.sh
+bash -n scripts/pr-preflight.sh
+bash -n scripts/release-preflight.sh
+
+./scripts/bump-version.sh --check
+./scripts/sync-copy.sh --check
+
+cd "$worktree/tools/cli"
+npm ci
+npm run ci:pr
+
+cd "$worktree"
+if [[ "$run_smoke" -eq 1 ]]; then
+  tools/cli/node_modules/.bin/tsx .github/scripts/openprose-smoke/run.ts \
+    --dry-run \
+    --tier required \
+    --force \
+    --results-dir openprose-smoke-results-local
+fi
+
+printf 'ok: PR preflight passed against %s\n' "$base_ref"
diff --git a/tools/cli/package.json b/tools/cli/package.json
index 18ff4696..cb4e292b 100644
--- a/tools/cli/package.json
+++ b/tools/cli/package.json
@@ -52,6 +52,7 @@
     "typecheck": "tsc -p tsconfig.json --noEmit",
     "test": "vitest --run",
     "audit:policy": "node scripts/audit-policy.mjs",
+    "ci:pr": "npm test && npm run typecheck && npm run build && npm run audit:policy",
     "smoke:harness": "node scripts/smoke-harness.mjs",
     "dev": "tsx src/index.ts",
     "clean": "rm -rf dist",