diff --git a/.github/workflows/release-pr.yml b/.github/workflows/release-pr.yml
index 950efd7..31ff7e4 100644
--- a/.github/workflows/release-pr.yml
+++ b/.github/workflows/release-pr.yml
@@ -20,12 +20,17 @@ jobs:
       - uses: actions/setup-python@v6.2.0
         with:
           python-version: "3.11"
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20"
       - name: Install package
         run: python -m pip install -e . pytest build
       - name: Check version consistency
         run: python scripts/check_versions.py
       - name: Validate marketplace manifest
         run: python scripts/validate_codex_marketplace.py
+      - name: Inspect npm package contents
+        run: python scripts/inspect_npm_package.py
       - name: Run tests
         run: pytest -q
       - name: Build sdist + wheel
diff --git a/scripts/inspect_npm_package.py b/scripts/inspect_npm_package.py
new file mode 100644
index 0000000..2e59294
--- /dev/null
+++ b/scripts/inspect_npm_package.py
@@ -0,0 +1,135 @@
+#!/usr/bin/env python3
+"""Inspect a packed npm tarball and verify it ships the contents users need.
+
+The packed tarball (``npm pack`` output) is the interface under test: this
+checks what gets published, independent of any registry. Run with no argument
+to pack the repo and inspect it, or pass a ``.tgz`` to inspect directly.
+"""
+
+from __future__ import annotations
+
+import json
+import subprocess
+import sys
+import tarfile
+from pathlib import Path
+
+# Files every consumer of the npm artifact relies on.
+REQUIRED_FILES = (
+    "bin/install.js",
+    "package.json",
+    "install.sh",
+    "install.ps1",
+    "skills-lock.json",
+)
+# Console-script entrypoints package.json must expose.
+REQUIRED_BINS = ("codeforerunner", "codeforerunner-install")
+
+
+def _strip_prefix(name: str) -> str:
+    """Drop the leading ``package/`` dir npm wraps every member in."""
+    parts = name.split("/", 1)
+    return parts[1] if len(parts) == 2 and parts[0] == "package" else name
+
+
+def _read_members(tar: tarfile.TarFile) -> set[str]:
+    return {_strip_prefix(m.name) for m in tar.getmembers() if m.isfile()}
+
+
+def _read_text(tar: tarfile.TarFile, member: str) -> str | None:
+    for m in tar.getmembers():
+        if _strip_prefix(m.name) == member and m.isfile():
+            f = tar.extractfile(m)
+            if f is not None:
+                return f.read().decode("utf-8")
+    return None
+
+
+def inspect_package(tarball_path: Path) -> list[str]:
+    """Return a list of content problems; empty means the artifact is good."""
+    problems: list[str] = []
+    with tarfile.open(tarball_path, "r:*") as tar:
+        members = _read_members(tar)
+
+        for required in REQUIRED_FILES:
+            if required not in members:
+                problems.append(f"missing required file: {required}")
+
+        if not any(m.startswith("skills/") for m in members):
+            problems.append("missing skill payloads: skills/ is empty")
+
+        problems.extend(_check_bins(tar, members))
+        problems.extend(_check_locked_skills(tar, members))
+
+    return problems
+
+
+def _check_locked_skills(tar: tarfile.TarFile, members: set[str]) -> list[str]:
+    """Every skill the lock declares must actually ship in the tarball."""
+    if "skills-lock.json" not in members:
+        return []  # already reported as a missing required file
+    raw = _read_text(tar, "skills-lock.json")
+    try:
+        skills = json.loads(raw or "").get("skills", {})
+    except json.JSONDecodeError:
+        return ["skills-lock.json is not valid JSON"]
+    problems = []
+    for entry in skills.values():
+        path = entry.get("skillPath")
+        if path and path not in members:
+            problems.append(f"skill declared in skills-lock.json but absent from package: {path}")
+    return problems
+
+
+def _check_bins(tar: tarfile.TarFile, members: set[str]) -> list[str]:
+    if "package.json" not in members:
+        return []  # already reported as a missing required file
+    raw = _read_text(tar, "package.json")
+    try:
+        bins = json.loads(raw or "").get("bin", {})
+    except json.JSONDecodeError:
+        return ["package.json is not valid JSON"]
+    return [
+        f"missing bin entrypoint in package.json: {name}"
+        for name in REQUIRED_BINS
+        if name not in bins
+    ]
+
+
+def main(argv: list[str]) -> int:
+    if argv:
+        tarball = Path(argv[0])
+        created = False
+    else:
+        tarball = _npm_pack()
+        created = True
+    try:
+        problems = inspect_package(tarball)
+    finally:
+        if created:
+            tarball.unlink(missing_ok=True)
+
+    if problems:
+        print("npm package contents FAILED validation:", file=sys.stderr)
+        for p in problems:
+            print(f"  - {p}", file=sys.stderr)
+        return 1
+    print(f"npm package contents OK ({tarball.name})")
+    return 0
+
+
+def _npm_pack() -> Path:
+    root = Path(__file__).resolve().parent.parent
+    out = subprocess.run(
+        ["npm", "pack", "--json"],
+        cwd=root,
+        check=True,
+        capture_output=True,
+        text=True,
+    )
+    filename = json.loads(out.stdout)[0]["filename"]
+    return root / filename
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv[1:]))
diff --git a/tests/test_inspect_npm_package.py b/tests/test_inspect_npm_package.py
new file mode 100644
index 0000000..cc666db
--- /dev/null
+++ b/tests/test_inspect_npm_package.py
@@ -0,0 +1,122 @@
+"""Behavior tests for scripts/inspect_npm_package.py.
+
+The interface under test is the packed npm tarball: each test builds a tarball
+shaped like ``npm pack`` output (every member under a ``package/`` prefix) and
+asserts what the inspector reports about its contents.
+"""
+
+from __future__ import annotations
+
+import importlib.util
+import io
+import json
+import shutil
+import sys
+import tarfile
+from pathlib import Path
+
+import pytest
+
+SCRIPT_PATH = Path(__file__).resolve().parent.parent / "scripts" / "inspect_npm_package.py"
+
+
+def _load_inspector():
+    spec = importlib.util.spec_from_file_location("inspect_npm_package", SCRIPT_PATH)
+    assert spec is not None and spec.loader is not None
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[spec.name] = module
+    spec.loader.exec_module(module)
+    return module
+
+
+inspect_npm_package = _load_inspector()
+
+
+# --- fixture builder ------------------------------------------------------
+
+_SKILLS_LOCK = {
+    "version": 1,
+    "skills": {
+        "codeforerunner": {"skillPath": "skills/codeforerunner/SKILL.md"},
+        "forerunner-scan": {"skillPath": "skills/forerunner-scan/SKILL.md"},
+    },
+}
+
+_PACKAGE_JSON = {
+    "name": "codeforerunner",
+    "version": "0.4.5",
+    "bin": {
+        "codeforerunner": "bin/install.js",
+        "codeforerunner-install": "bin/install.js",
+    },
+}
+
+
+def _well_formed_members() -> dict[str, str]:
+    """Member-path → text content for a complete, valid package."""
+    return {
+        "bin/install.js": "// installer\n",
+        "package.json": json.dumps(_PACKAGE_JSON),
+        "install.sh": "#!/bin/sh\n",
+        "install.ps1": "# ps1\n",
+        "skills-lock.json": json.dumps(_SKILLS_LOCK),
+        "skills/codeforerunner/SKILL.md": "# codeforerunner\n",
+        "skills/forerunner-scan/SKILL.md": "# scan\n",
+    }
+
+
+def _write_tarball(tmp_path: Path, members: dict[str, str]) -> Path:
+    """Pack ``members`` into an npm-style tarball (``package/`` prefix)."""
+    tarball = tmp_path / "codeforerunner-0.4.5.tgz"
+    with tarfile.open(tarball, "w:gz") as tar:
+        for name, content in members.items():
+            raw = content.encode("utf-8")
+            info = tarfile.TarInfo(name=f"package/{name}")
+            info.size = len(raw)
+            tar.addfile(info, io.BytesIO(raw))
+    return tarball
+
+
+# --- tests ----------------------------------------------------------------
+
+
+def test_well_formed_package_has_no_problems(tmp_path):
+    tarball = _write_tarball(tmp_path, _well_formed_members())
+    assert inspect_npm_package.inspect_package(tarball) == []
+
+
+def test_missing_required_file_is_reported(tmp_path):
+    members = _well_formed_members()
+    del members["bin/install.js"]
+    tarball = _write_tarball(tmp_path, members)
+    problems = inspect_npm_package.inspect_package(tarball)
+    assert any("bin/install.js" in p for p in problems)
+
+
+def test_missing_bin_entrypoint_is_reported(tmp_path):
+    members = _well_formed_members()
+    pkg = dict(_PACKAGE_JSON)
+    pkg["bin"] = {"codeforerunner": "bin/install.js"}  # drop codeforerunner-install
+    members["package.json"] = json.dumps(pkg)
+    tarball = _write_tarball(tmp_path, members)
+    problems = inspect_npm_package.inspect_package(tarball)
+    assert any("codeforerunner-install" in p for p in problems)
+
+
+def test_skill_declared_in_lock_but_absent_is_reported(tmp_path):
+    members = _well_formed_members()
+    del members["skills/forerunner-scan/SKILL.md"]  # lock still declares it
+    tarball = _write_tarball(tmp_path, members)
+    problems = inspect_npm_package.inspect_package(tarball)
+    assert any("forerunner-scan/SKILL.md" in p for p in problems)
+
+
+@pytest.mark.skipif(shutil.which("npm") is None, reason="npm not available")
+def test_real_repo_npm_pack_passes_inspection():
+    # End-to-end against actual `npm pack` output: the published artifact this
+    # repo produces today must satisfy the inspector.
+    tarball = inspect_npm_package._npm_pack()
+    try:
+        assert inspect_npm_package.inspect_package(tarball) == []
+    finally:
+        tarball.unlink(missing_ok=True)
diff --git a/tests/test_workflows_yaml.py b/tests/test_workflows_yaml.py
index 73523b5..9f4653b 100644
--- a/tests/test_workflows_yaml.py
+++ b/tests/test_workflows_yaml.py
@@ -156,6 +156,8 @@ def test_release_pr_workflow_requires_release_signal_and_uploads_artifacts():
     assert "actions/upload-artifact" in steps_text
     assert "scripts/check_versions.py" in steps_text
     assert "scripts/validate_codex_marketplace.py" in steps_text
+    # npm artifact contents are validated before any tagged publish.
+    assert "scripts/inspect_npm_package.py" in steps_text
 
 
 def test_forerunner_check_workflow_always_runs():