diff --git a/tests/rust-python-harness/strategies/__init__.py b/tests/rust-python-harness/strategies/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/rust-python-harness/strategies/unit_tests/__init__.py b/tests/rust-python-harness/strategies/unit_tests/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/rust-python-harness/strategies/unit_tests/mapping_validator.py b/tests/rust-python-harness/strategies/unit_tests/mapping_validator.py
new file mode 100644
index 00000000000..b8355e04266
--- /dev/null
+++ b/tests/rust-python-harness/strategies/unit_tests/mapping_validator.py
@@ -0,0 +1,101 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from pathlib import Path
+
+from ...shared.parity.ledger import TestLedger, load_ledger
+from .python_runner import enumerate_python_tests
+from .rust_runner import enumerate_rust_tests
+
+REPO_ROOT = Path(__file__).resolve().parents[4]
+LEDGER_ROOT = Path(__file__).parent / "ledgers"
+
+
+def ledger_path_for(sdk_function: str) -> Path:
+    return LEDGER_ROOT / sdk_function / f"{sdk_function}_test_ledger.json"
+
+
+@dataclass(frozen=True, slots=True)
+class AuditReport:
+    missing_python_tests: tuple[str, ...]
+    stale_python_tests: tuple[str, ...]
+    missing_rust_tests: tuple[str, ...]
+    stale_rust_tests: tuple[str, ...]
+
+    @property
+    def is_clean(self) -> bool:
+        return not (
+            self.missing_python_tests
+            or self.stale_python_tests
+            or self.missing_rust_tests
+            or self.stale_rust_tests
+        )
+
+
+def _ledger_python_tests_by_file(ledger: TestLedger) -> dict[str, set[str]]:
+    grouping: dict[str, set[str]] = {path: set() for path in ledger.python_scope}
+    for entry in ledger.entries:
+        grouping.setdefault(entry.python_file, set()).add(entry.python_test)
+    return grouping
+
+
+def _ledger_rust_tests_by_file(ledger: TestLedger) -> dict[str, set[str]]:
+    grouping: dict[str, set[str]] = {path: set() for path in ledger.rust_scope}
+    for entry in ledger.entries:
+        if entry.status == "mapped":
+            grouping.setdefault(entry.rust_file, set()).add(entry.rust_test)
+    for rust_only in ledger.rust_only_tests:
+        grouping.setdefault(rust_only.rust_file, set()).add(rust_only.rust_test)
+    return grouping
+
+
+def audit_ledger(ledger: TestLedger, repo_root: Path = REPO_ROOT) -> AuditReport:
+    missing_python: list[str] = []
+    stale_python: list[str] = []
+    for python_file, ledger_tests in _ledger_python_tests_by_file(ledger).items():
+        actual_tests = enumerate_python_tests(repo_root, python_file)
+        for missing in sorted(ledger_tests - actual_tests):
+            missing_python.append(f"{python_file}:{missing}")
+        for stale in sorted(actual_tests - ledger_tests):
+            stale_python.append(f"{python_file}:{stale}")
+
+    missing_rust: list[str] = []
+    stale_rust: list[str] = []
+    for rust_file, ledger_tests in _ledger_rust_tests_by_file(ledger).items():
+        actual_tests = enumerate_rust_tests(repo_root, rust_file)
+        for missing in sorted(ledger_tests - actual_tests):
+            missing_rust.append(f"{rust_file}:{missing}")
+        for stale in sorted(actual_tests - ledger_tests):
+            stale_rust.append(f"{rust_file}:{stale}")
+
+    return AuditReport(
+        missing_python_tests=tuple(missing_python),
+        stale_python_tests=tuple(stale_python),
+        missing_rust_tests=tuple(missing_rust),
+        stale_rust_tests=tuple(stale_rust),
+    )
+
+
+@dataclass(frozen=True, slots=True)
+class FunctionReport:
+    sdk_function: str
+    ledger: TestLedger | None
+    audit: AuditReport | None
+
+    @property
+    def has_ledger(self) -> bool:
+        return self.ledger is not None
+
+    @property
+    def is_clean(self) -> bool:
+        return self.audit is None or self.audit.is_clean
+
+
+def build_function_report(sdk_function: str, repo_root: Path = REPO_ROOT) -> FunctionReport:
+    path = ledger_path_for(sdk_function)
+    if not path.exists():
+        return FunctionReport(sdk_function=sdk_function, ledger=None, audit=None)
+    ledger = load_ledger(path)
+    return FunctionReport(
+        sdk_function=sdk_function, ledger=ledger, audit=audit_ledger(ledger, repo_root)
+    )