diff --git a/.github/workflows/pr-gate.yml b/.github/workflows/pr-gate.yml
new file mode 100644
index 0000000..221a20c
--- /dev/null
+++ b/.github/workflows/pr-gate.yml
@@ -0,0 +1,41 @@
+name: pr-gate
+
+# Every pull request runs this repo's own check suite (scripts/check.sh) plus the shared em-dash and
+# workflow-pinning guards. Those guards live in lib_bespok3d, mounted here as a git submodule, so the
+# checkout must fetch it.
+#
+# The repo's own checkout uses the auto GITHUB_TOKEN, which is always valid for this repo. The submodule
+# lives in a SEPARATE private repo that GITHUB_TOKEN cannot read, so it is fetched in its own step with a
+# read token (MAIN_INDEX_TOKEN). The main checkout runs with persist-credentials off so it does not leave
+# GITHUB_TOKEN in git config, where it would otherwise be reused for the submodule fetch and 403 on the
+# private repo. The submodule URL in .gitmodules is HTTPS so the token applies.
+#
+# This is a check-only run: it never builds, packs, signs or publishes, so no signing key is in scope.
+# The single secret it holds is the submodule read token. It is deliberately NOT named pr-build.yml: that
+# name is reserved for a b3-builder preview build, which the pinning guard forbids from holding any secret
+# at all. See the go-public finding: swap this token for a read-only one, or make lib_bespok3d public,
+# before external forks open PRs (a fork PR receives no secret and its checkout of the private submodule
+# would fail).
+on:
+  pull_request:
+
+jobs:
+  gate:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: false
+          persist-credentials: false
+
+      - name: Fetch the shared-tooling submodule
+        run: |
+          git config --global url."https://x-access-token:${{ secrets.MAIN_INDEX_TOKEN }}@github.com/".insteadOf "https://github.com/"
+          git submodule update --init --recursive
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Repo gate (shared detectors + check suite)
+        run: bash scripts/check.sh
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..dd7e77d
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "lib_bespok3d"]
+	path = lib_bespok3d
+	url = https://github.com/Bespok3d/lib_bespok3d.git
diff --git a/lib_bespok3d b/lib_bespok3d
new file mode 160000
index 0000000..8ce6759
--- /dev/null
+++ b/lib_bespok3d
@@ -0,0 +1 @@
+Subproject commit 8ce67593b469619306db0c9f389ac21cedaf1a31
diff --git a/scripts/check.sh b/scripts/check.sh
new file mode 100755
index 0000000..564f8a9
--- /dev/null
+++ b/scripts/check.sh
@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+# This repo's own gate: it must pass from this repo's root, with no sibling repo cloned except
+# lib_bespok3d. Exits non-zero on any failure.
+set -uo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+# The shared gate helpers and the detectors that enforce a workspace-wide rule live in one place.
+# See lib_bespok3d/tooling/README.md. This is the only line that knows where they are.
+B3D_TOOLING="${B3D_TOOLING:-$REPO_ROOT/lib_bespok3d/tooling}"
+# shellcheck source=/dev/null
+. "$B3D_TOOLING/gate-lib.sh"
+
+cd "$REPO_ROOT" || exit 1
+
+echo ""
+echo "reference-python-plugins gate"
+
+b3d_python_tools
+
+# print-time-human vendors humanize under files/site-packages, so its own tree is the import path
+# its tests and its type checks resolve against.
+export PYTHONPATH="$REPO_ROOT/print-time-human/files/site-packages"
+
+# That vendored tree is gitignored (baked into the package at publish), so a clean checkout, which
+# is what CI gets, has no humanize: the status-feed test would importorskip it and never run,
+# leaving the gate green on an untested plugin. Provision the plugin's own declared dependency into
+# the tree PYTHONPATH resolves against so the test actually exercises the code. B3D_PY is the gate's
+# tool interpreter, provisioned by b3d_python_tools above.
+"$B3D_PY" -m pip install --quiet --target "$REPO_ROOT/print-time-human/files/site-packages" -r "$REPO_ROOT/status-feed/requirements.txt"
+
+run_check "pytest (status-feed)"  pytest_in_dir "$REPO_ROOT/status-feed" tests
+run_check "ruff (status-feed)"    ruff_in_dir "$REPO_ROOT/status-feed" files tests
+run_check "ruff (print-time-human)" ruff_in_dir "$REPO_ROOT/print-time-human" files/klipper
+
+unset PYTHONPATH
+
+workflow_pinning_check "$REPO_ROOT"
+em_dash_check "$REPO_ROOT"
+shellcheck_repo "$REPO_ROOT"
+
+gate_summary || exit 1