diff --git a/tests/test_opencode_asyncio_toolchain_contract.py b/tests/test_opencode_asyncio_toolchain_contract.py
new file mode 100644
index 000000000..4b35ee94f
--- /dev/null
+++ b/tests/test_opencode_asyncio_toolchain_contract.py
@@ -0,0 +1,18 @@
+from pathlib import Path
+
+
+REVIEW_REQUIREMENTS_PATH = Path("requirements-opencode-review-ci.txt")
+REVIEW_HASH_LOCK_PATH = Path("requirements-opencode-review-ci-hashes.txt")
+REVIEW_WORKFLOW_PATH = Path(".github/workflows/opencode-review-dispatch.yml")
+
+
+def test_opencode_coverage_toolchain_supports_repository_asyncio_tests() -> None:
+    """Keep the trusted coverage sandbox able to execute marked asyncio tests."""
+
+    requirements = REVIEW_REQUIREMENTS_PATH.read_text(encoding="utf-8")
+    hash_lock = REVIEW_HASH_LOCK_PATH.read_text(encoding="utf-8")
+    workflow = REVIEW_WORKFLOW_PATH.read_text(encoding="utf-8")
+
+    assert "pytest-asyncio==1.4.0" in requirements
+    assert "pytest-asyncio==1.4.0" in hash_lock
+    assert "import coverage, interrogate, pytest, pytest_asyncio, pytest_cov" in workflow