diff --git a/tests/audit/__init__.py b/tests/audit/__init__.py
new file mode 100644
index 00000000..bcf61803
--- /dev/null
+++ b/tests/audit/__init__.py
@@ -0,0 +1 @@
+"""Consistency audit tests — validate L1 mock expectations against L4 golden dataset ground truth."""
diff --git a/tests/audit/conftest.py b/tests/audit/conftest.py
new file mode 100644
index 00000000..592aff76
--- /dev/null
+++ b/tests/audit/conftest.py
@@ -0,0 +1,189 @@
+"""Audit test fixtures — vault builder, CLI invoker, golden vault, snapshot comparators.
+
+These fixtures build real vaults from golden dataset fixtures and run the paperforge
+CLI via subprocess — same L4 boundary as E2E tests. The purpose is to validate
+that L1 mock expectations still match real pipeline output.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import stat
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+
+
+# ---------------------------------------------------------------------------
+# Windows-safe recursive directory removal
+# ---------------------------------------------------------------------------
+def _force_rmtree(root: Path) -> None:
+    """Remove a directory tree, handling Windows file-locking issues."""
+    for dirpath, dirnames, filenames in os.walk(str(root)):
+        for f in filenames:
+            try:
+                os.chmod(os.path.join(dirpath, f), stat.S_IWRITE)
+            except OSError:
+                pass
+        for d in dirnames:
+            try:
+                os.chmod(os.path.join(dirpath, d), stat.S_IWRITE)
+            except OSError:
+                pass
+    shutil.rmtree(str(root), ignore_errors=True)
+
+
+# ---------------------------------------------------------------------------
+# Path helpers
+# ---------------------------------------------------------------------------
+REPO_ROOT = Path(__file__).resolve().parent.parent.parent
+FIXTURES_DIR = REPO_ROOT / "fixtures"
+SNAPSHOTS_DIR = FIXTURES_DIR / "snapshots"
+OCR_FIXTURES_DIR = FIXTURES_DIR / "ocr"
+
+
+# ---------------------------------------------------------------------------
+# Fixtures
+# ---------------------------------------------------------------------------
+@pytest.fixture(scope="session")
+def vault_builder() -> object:
+    """Session-scoped VaultBuilder instance connected to fixtures/ directory."""
+    from fixtures.vault_builder import VaultBuilder
+    return VaultBuilder()
+
+
+@pytest.fixture
+def cli_invoker(vault_builder: object) -> callable:
+    """Returns a callable that runs paperforge CLI subprocess in a disposable vault.
+
+    Unlike other conftest files, the default vault_level is "full" — audit tests
+    need the richest golden dataset to validate cross-layer consistency.
+
+    The returned callable accepts:
+        args: list[str] — CLI arguments
+        vault_level: str — vault completeness level (default "full")
+        input_text: str | None — stdin text
+        env: dict | None — additional env vars
+
+    Returns:
+        subprocess.CompletedProcess with stdout, stderr, returncode
+    """
+    vaults: list[Path] = []
+
+    def _invoke(
+        args: list[str],
+        vault_level: str = "full",
+        input_text: str | None = None,
+        env: dict | None = None,
+    ) -> subprocess.CompletedProcess:
+        vault = Path(vault_builder.build(vault_level))
+        vaults.append(vault)
+
+        cmd = [sys.executable, "-m", "paperforge", "--vault", str(vault)] + args
+
+        base_env = {**os.environ.copy(), "PAPERFORGE_VAULT": str(vault)}
+        if env:
+            base_env.update(env)
+
+        result = subprocess.run(
+            cmd,
+            capture_output=True,
+            text=True,
+            timeout=120,
+            input=input_text,
+            env=base_env,
+        )
+        return result
+
+    yield _invoke
+
+    for v in vaults:
+        if v.exists():
+            _force_rmtree(v)
+
+
+@pytest.fixture
+def golden_vault(vault_builder: object) -> tuple[callable, Path]:
+    """Build a "full" vault, run the real sync pipeline, return (invoker, vault_path).
+
+    This is the L4 golden dataset — any mock drift against L1 snapshots will be
+    detected by comparing the output of this fixture against snapshot contracts.
+
+    Returns:
+        (invoke_fn, vault_path) tuple. The invoker function automatically targets
+        this specific vault (omit vault_level — it is pre-set).
+    """
+    vault_paths: list[Path] = []
+
+    def _setup() -> tuple[callable, Path]:
+        # Build a fresh full vault for golden dataset comparison
+        vault = Path(vault_builder.build("full"))
+        vault_paths.append(vault)
+
+        def _invoke_in_golden(
+            args: list[str],
+            input_text: str | None = None,
+            env: dict | None = None,
+        ) -> subprocess.CompletedProcess:
+            cmd = [sys.executable, "-m", "paperforge", "--vault", str(vault)] + args
+            base_env = {**os.environ.copy(), "PAPERFORGE_VAULT": str(vault)}
+            if env:
+                base_env.update(env)
+            return subprocess.run(
+                cmd,
+                capture_output=True,
+                text=True,
+                timeout=120,
+                input=input_text,
+                env=base_env,
+            )
+
+        # Run the real sync pipeline to create formal notes + index
+        _invoke_in_golden(["sync"])
+
+        return (_invoke_in_golden, vault)
+
+    result = _setup()
+    yield result
+
+    for v in vault_paths:
+        if v.exists():
+            _force_rmtree(v)
+
+
+@pytest.fixture
+def snapshot_contracts() -> dict[str, object]:
+    """Load all snapshot contracts from fixtures/snapshots/.
+
+    Returns:
+        dict mapping contract name -> parsed content (JSON for .json, YAML for .yaml)
+    """
+    contracts: dict[str, object] = {}
+
+    if SNAPSHOTS_DIR.exists():
+        for snap_file in SNAPSHOTS_DIR.rglob("*"):
+            if not snap_file.is_file():
+                continue
+            rel = snap_file.relative_to(SNAPSHOTS_DIR)
+            key = str(rel.as_posix())
+
+            if snap_file.suffix == ".json":
+                contracts[key] = json.loads(snap_file.read_text(encoding="utf-8"))
+            elif snap_file.suffix in (".yaml", ".yml"):
+                import yaml
+                contracts[key] = yaml.safe_load(snap_file.read_text(encoding="utf-8"))
+
+    return contracts
+
+
+@pytest.fixture
+def golden_dataset_manifest() -> dict:
+    """Load and return fixtures/MANIFEST.json as a dict."""
+    manifest_path = FIXTURES_DIR / "MANIFEST.json"
+    if manifest_path.exists():
+        return json.loads(manifest_path.read_text(encoding="utf-8"))
+    return {"fixtures": []}