diff --git a/scripts/check.sh b/scripts/check.sh
new file mode 100755
index 0000000..cf6d605
--- /dev/null
+++ b/scripts/check.sh
@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+# The single pre-merge gate for wiggleverse-ecomm (SD-0001 §6.8). Runs, in order:
+#   1. the import-linter layering contract  (main > domains > platform)
+#   2. the backend test suite                (pytest, against Postgres)
+#   3. the frontend typecheck + production build
+# CI (.gitea/workflows/ci.yml) calls this exact script, so local and server gates
+# cannot drift. Exits non-zero on the first failure.
+#
+# Requires a reachable Postgres for the backend tests: locally the compose service
+# (scripts/dev.sh brings it up); in CI a Postgres service container. Override its
+# admin DSN with ECOMM_TEST_ADMIN_URL.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+
+# Pick an interpreter: explicit $PYTHON (CI), else the repo venv, else PATH.
+if [ -n "${PYTHON:-}" ]; then
+  PY="$PYTHON"
+elif [ -x "$repo_root/.venv/bin/python" ]; then
+  PY="$repo_root/.venv/bin/python"
+else
+  PY="$(command -v python3 || command -v python)"
+fi
+
+lint="$(dirname "$PY")/lint-imports"
+[ -x "$lint" ] || lint="lint-imports"
+
+echo "==> import boundaries (lint-imports)"
+( cd "$repo_root/backend" && "$lint" )
+
+echo "==> backend tests (pytest)"
+( cd "$repo_root/backend" && "$PY" -m pytest -q )
+
+echo "==> frontend typecheck + build"
+( cd "$repo_root/frontend" && npm run build )
+
+echo "==> all gates green"