diff --git a/key-value/key-value-aio/tests/stores/wrappers/test_encryption.py b/key-value/key-value-aio/tests/stores/wrappers/test_encryption.py
index 6c6e5f5b..8ba60f17 100644
--- a/key-value/key-value-aio/tests/stores/wrappers/test_encryption.py
+++ b/key-value/key-value-aio/tests/stores/wrappers/test_encryption.py
@@ -175,3 +175,70 @@ def test_key_generation():
     assert key_str_one != key_str_two
     assert key_str_one != key_str_three
     assert key_str_two != key_str_three
+
+
+def test_fernet_with_source_material_and_salt(memory_store: MemoryStore):
+    """Test that FernetEncryptionWrapper works with source_material and salt."""
+    wrapper = FernetEncryptionWrapper(
+        key_value=memory_store,
+        source_material="my-secret-key",
+        salt="my-unique-salt",
+    )
+    assert wrapper is not None
+
+
+def test_fernet_cannot_provide_fernet_with_source_material(memory_store: MemoryStore):
+    """Test that providing both fernet and source_material raises ValueError."""
+    fernet = Fernet(key=Fernet.generate_key())
+    with pytest.raises(ValueError, match="Cannot provide fernet together with source_material or salt"):
+        FernetEncryptionWrapper(
+            key_value=memory_store,
+            fernet=fernet,
+            source_material="test",
+        )
+
+
+def test_fernet_cannot_provide_fernet_with_salt(memory_store: MemoryStore):
+    """Test that providing both fernet and salt raises ValueError."""
+    fernet = Fernet(key=Fernet.generate_key())
+    with pytest.raises(ValueError, match="Cannot provide fernet together with source_material or salt"):
+        FernetEncryptionWrapper(
+            key_value=memory_store,
+            fernet=fernet,
+            salt="test",
+        )
+
+
+def test_fernet_must_provide_source_material(memory_store: MemoryStore):
+    """Test that not providing fernet or source_material raises ValueError."""
+    with pytest.raises(ValueError, match="Must provide either fernet or source_material"):
+        FernetEncryptionWrapper(key_value=memory_store)
+
+
+def test_fernet_must_provide_salt_with_source_material(memory_store: MemoryStore):
+    """Test that providing source_material without salt raises ValueError."""
+    with pytest.raises(ValueError, match="Must provide a salt"):
+        FernetEncryptionWrapper(
+            key_value=memory_store,
+            source_material="test-source",
+        )
+
+
+def test_fernet_empty_source_material(memory_store: MemoryStore):
+    """Test that empty source_material raises ValueError."""
+    with pytest.raises(ValueError, match="Must provide either fernet or source_material"):
+        FernetEncryptionWrapper(
+            key_value=memory_store,
+            source_material="   ",
+            salt="test",
+        )
+
+
+def test_fernet_empty_salt(memory_store: MemoryStore):
+    """Test that empty salt raises ValueError."""
+    with pytest.raises(ValueError, match="Must provide a salt"):
+        FernetEncryptionWrapper(
+            key_value=memory_store,
+            source_material="test-source",
+            salt="   ",
+        )
diff --git a/key-value/key-value-aio/tests/stores/wrappers/test_fallback.py b/key-value/key-value-aio/tests/stores/wrappers/test_fallback.py
index 80bab234..b6a497a4 100644
--- a/key-value/key-value-aio/tests/stores/wrappers/test_fallback.py
+++ b/key-value/key-value-aio/tests/stores/wrappers/test_fallback.py
@@ -1,4 +1,4 @@
-from collections.abc import Mapping
+from collections.abc import Mapping, Sequence
 from typing import Any, SupportsFloat
 
 import pytest
@@ -17,11 +17,43 @@ async def get(self, key: str, *, collection: str | None = None) -> dict[str, Any
         msg = "Primary store unavailable"
         raise ConnectionError(msg)
 
+    @override
+    async def get_many(self, keys: Sequence[str], *, collection: str | None = None) -> list[dict[str, Any] | None]:
+        msg = "Primary store unavailable"
+        raise ConnectionError(msg)
+
+    @override
+    async def ttl(self, key: str, *, collection: str | None = None) -> tuple[dict[str, Any] | None, float | None]:
+        msg = "Primary store unavailable"
+        raise ConnectionError(msg)
+
+    @override
+    async def ttl_many(self, keys: Sequence[str], *, collection: str | None = None) -> list[tuple[dict[str, Any] | None, float | None]]:
+        msg = "Primary store unavailable"
+        raise ConnectionError(msg)
+
     @override
     async def put(self, key: str, value: Mapping[str, Any], *, collection: str | None = None, ttl: SupportsFloat | None = None):
         msg = "Primary store unavailable"
         raise ConnectionError(msg)
 
+    @override
+    async def put_many(
+        self, keys: Sequence[str], values: Sequence[Mapping[str, Any]], *, collection: str | None = None, ttl: SupportsFloat | None = None
+    ) -> None:
+        msg = "Primary store unavailable"
+        raise ConnectionError(msg)
+
+    @override
+    async def delete(self, key: str, *, collection: str | None = None) -> bool:
+        msg = "Primary store unavailable"
+        raise ConnectionError(msg)
+
+    @override
+    async def delete_many(self, keys: Sequence[str], *, collection: str | None = None) -> int:
+        msg = "Primary store unavailable"
+        raise ConnectionError(msg)
+
 
 class TestFallbackWrapper(BaseStoreTests):
     @override
@@ -77,3 +109,81 @@ async def test_write_to_fallback_enabled(self):
         # Verify it was written to fallback
         result = await fallback_store.get(collection="test", key="test")
         assert result == {"test": "value"}
+
+    async def test_fallback_get_many(self):
+        primary_store = FailingStore()
+        fallback_store = MemoryStore()
+        wrapper = FallbackWrapper(primary_key_value=primary_store, fallback_key_value=fallback_store)
+
+        # Put data in fallback store
+        await fallback_store.put(collection="test", key="k1", value={"v": "1"})
+        await fallback_store.put(collection="test", key="k2", value={"v": "2"})
+
+        # Should fall back for get_many
+        result = await wrapper.get_many(collection="test", keys=["k1", "k2"])
+        assert result == [{"v": "1"}, {"v": "2"}]
+
+    async def test_fallback_ttl(self):
+        primary_store = FailingStore()
+        fallback_store = MemoryStore()
+        wrapper = FallbackWrapper(primary_key_value=primary_store, fallback_key_value=fallback_store)
+
+        # Put data in fallback store with TTL
+        await fallback_store.put(collection="test", key="test", value={"v": "1"}, ttl=100)
+
+        # Should fall back for ttl
+        value, ttl = await wrapper.ttl(collection="test", key="test")
+        assert value == {"v": "1"}
+        assert ttl is not None
+
+    async def test_fallback_ttl_many(self):
+        primary_store = FailingStore()
+        fallback_store = MemoryStore()
+        wrapper = FallbackWrapper(primary_key_value=primary_store, fallback_key_value=fallback_store)
+
+        # Put data in fallback store
+        await fallback_store.put(collection="test", key="k1", value={"v": "1"}, ttl=100)
+        await fallback_store.put(collection="test", key="k2", value={"v": "2"}, ttl=200)
+
+        # Should fall back for ttl_many
+        results = await wrapper.ttl_many(collection="test", keys=["k1", "k2"])
+        assert results[0][0] == {"v": "1"}
+        assert results[1][0] == {"v": "2"}
+
+    async def test_fallback_put_many_enabled(self):
+        primary_store = FailingStore()
+        fallback_store = MemoryStore()
+        wrapper = FallbackWrapper(primary_key_value=primary_store, fallback_key_value=fallback_store, write_to_fallback=True)
+
+        # Should fall back for put_many
+        await wrapper.put_many(collection="test", keys=["k1", "k2"], values=[{"v": "1"}, {"v": "2"}])
+
+        # Verify in fallback
+        assert await fallback_store.get(collection="test", key="k1") == {"v": "1"}
+        assert await fallback_store.get(collection="test", key="k2") == {"v": "2"}
+
+    async def test_fallback_delete_enabled(self):
+        primary_store = FailingStore()
+        fallback_store = MemoryStore()
+        wrapper = FallbackWrapper(primary_key_value=primary_store, fallback_key_value=fallback_store, write_to_fallback=True)
+
+        # Put data in fallback
+        await fallback_store.put(collection="test", key="test", value={"v": "1"})
+
+        # Should fall back for delete
+        result = await wrapper.delete(collection="test", key="test")
+        assert result is True
+        assert await fallback_store.get(collection="test", key="test") is None
+
+    async def test_fallback_delete_many_enabled(self):
+        primary_store = FailingStore()
+        fallback_store = MemoryStore()
+        wrapper = FallbackWrapper(primary_key_value=primary_store, fallback_key_value=fallback_store, write_to_fallback=True)
+
+        # Put data in fallback
+        await fallback_store.put(collection="test", key="k1", value={"v": "1"})
+        await fallback_store.put(collection="test", key="k2", value={"v": "2"})
+
+        # Should fall back for delete_many
+        result = await wrapper.delete_many(collection="test", keys=["k1", "k2"])
+        assert result == 2
diff --git a/key-value/key-value-aio/tests/stores/wrappers/test_passthrough_cache.py b/key-value/key-value-aio/tests/stores/wrappers/test_passthrough_cache.py
index 9bba9239..8f9a2660 100644
--- a/key-value/key-value-aio/tests/stores/wrappers/test_passthrough_cache.py
+++ b/key-value/key-value-aio/tests/stores/wrappers/test_passthrough_cache.py
@@ -28,3 +28,80 @@ async def cache_store(self, memory_store: MemoryStore) -> MemoryStore:
     async def store(self, primary_store: DiskStore, cache_store: MemoryStore) -> PassthroughCacheWrapper:
         primary_store._cache.clear()  # pyright: ignore[reportPrivateUsage]
         return PassthroughCacheWrapper(primary_key_value=primary_store, cache_key_value=cache_store)
+
+    async def test_ttl_caches_from_primary(self):
+        """Test that ttl retrieves from primary and caches the result."""
+        primary_store = MemoryStore()
+        cache_store = MemoryStore()
+        wrapper = PassthroughCacheWrapper(primary_key_value=primary_store, cache_key_value=cache_store)
+
+        # Put data in primary with TTL
+        await primary_store.put(collection="test", key="test", value={"v": "1"}, ttl=100)
+
+        # Call ttl - should get from primary and cache it
+        value, ttl = await wrapper.ttl(collection="test", key="test")
+        assert value == {"v": "1"}
+        assert ttl is not None
+
+        # Verify it's now in cache
+        cached_value = await cache_store.get(collection="test", key="test")
+        assert cached_value == {"v": "1"}
+
+    async def test_ttl_returns_cached_value(self):
+        """Test that ttl returns cached value when available."""
+        primary_store = MemoryStore()
+        cache_store = MemoryStore()
+        wrapper = PassthroughCacheWrapper(primary_key_value=primary_store, cache_key_value=cache_store)
+
+        # Put data only in cache
+        await cache_store.put(collection="test", key="test", value={"v": "cached"}, ttl=100)
+
+        # Call ttl - should return cached value
+        value, ttl = await wrapper.ttl(collection="test", key="test")
+        assert value == {"v": "cached"}
+        assert ttl is not None
+
+    async def test_ttl_returns_none_for_missing(self):
+        """Test that ttl returns (None, None) for missing entries."""
+        primary_store = MemoryStore()
+        cache_store = MemoryStore()
+        wrapper = PassthroughCacheWrapper(primary_key_value=primary_store, cache_key_value=cache_store)
+
+        # Call ttl for non-existent key
+        value, ttl = await wrapper.ttl(collection="test", key="missing")
+        assert value is None
+        assert ttl is None
+
+    async def test_ttl_many_caches_from_primary(self):
+        """Test that ttl_many retrieves from primary and caches results."""
+        primary_store = MemoryStore()
+        cache_store = MemoryStore()
+        wrapper = PassthroughCacheWrapper(primary_key_value=primary_store, cache_key_value=cache_store)
+
+        # Put data in primary with TTL
+        await primary_store.put(collection="test", key="k1", value={"v": "1"}, ttl=100)
+        await primary_store.put(collection="test", key="k2", value={"v": "2"}, ttl=200)
+
+        # Call ttl_many - should get from primary and cache
+        results = await wrapper.ttl_many(collection="test", keys=["k1", "k2"])
+        assert results[0][0] == {"v": "1"}
+        assert results[1][0] == {"v": "2"}
+
+        # Verify in cache
+        assert await cache_store.get(collection="test", key="k1") == {"v": "1"}
+        assert await cache_store.get(collection="test", key="k2") == {"v": "2"}
+
+    async def test_ttl_many_returns_cached_values(self):
+        """Test that ttl_many returns cached values when available."""
+        primary_store = MemoryStore()
+        cache_store = MemoryStore()
+        wrapper = PassthroughCacheWrapper(primary_key_value=primary_store, cache_key_value=cache_store)
+
+        # Put data in cache
+        await cache_store.put(collection="test", key="k1", value={"v": "cached1"}, ttl=100)
+        await cache_store.put(collection="test", key="k2", value={"v": "cached2"}, ttl=200)
+
+        # Call ttl_many - should return cached values
+        results = await wrapper.ttl_many(collection="test", keys=["k1", "k2"])
+        assert results[0][0] == {"v": "cached1"}
+        assert results[1][0] == {"v": "cached2"}
diff --git a/key-value/key-value-shared/tests/utils/test_serialization.py b/key-value/key-value-shared/tests/utils/test_serialization.py
index 1699a386..b350ab22 100644
--- a/key-value/key-value-shared/tests/utils/test_serialization.py
+++ b/key-value/key-value-shared/tests/utils/test_serialization.py
@@ -3,8 +3,9 @@
 import pytest
 from inline_snapshot import snapshot
 
+from key_value.shared.errors import DeserializationError, SerializationError
 from key_value.shared.utils.managed_entry import ManagedEntry
-from key_value.shared.utils.serialization import BasicSerializationAdapter
+from key_value.shared.utils.serialization import BasicSerializationAdapter, key_must_be, parse_datetime_str
 
 FIXED_DATETIME_ONE = datetime(2025, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
 FIXED_DATETIME_ONE_ISOFORMAT = FIXED_DATETIME_ONE.isoformat()
@@ -80,3 +81,92 @@ def test_entry_two(self, adapter: BasicSerializationAdapter):
 
         assert adapter.load_dict(data=adapter.dump_dict(entry=TEST_ENTRY_TWO)) == snapshot(TEST_ENTRY_TWO)
         assert adapter.load_json(json_str=adapter.dump_json(entry=TEST_ENTRY_TWO)) == snapshot(TEST_ENTRY_TWO)
+
+    def test_dump_dict_with_key_and_collection(self, adapter: BasicSerializationAdapter):
+        """Test dump_dict includes key and collection when provided."""
+        result = adapter.dump_dict(entry=TEST_ENTRY_ONE, key="my-key", collection="my-collection")
+        assert result["key"] == "my-key"
+        assert result["collection"] == "my-collection"
+
+    def test_dump_dict_with_datetime_format(self):
+        """Test dump_dict with datetime format instead of isoformat."""
+        adapter = BasicSerializationAdapter(date_format="datetime")
+        result = adapter.dump_dict(entry=TEST_ENTRY_ONE)
+        assert result["created_at"] == FIXED_DATETIME_ONE
+        assert result["expires_at"] == FIXED_DATETIME_ONE_PLUS_10_SECONDS
+
+    def test_load_dict_with_datetime_format(self):
+        """Test load_dict with datetime format instead of isoformat."""
+        adapter = BasicSerializationAdapter(date_format="datetime")
+        data = {
+            "created_at": FIXED_DATETIME_ONE,
+            "expires_at": FIXED_DATETIME_ONE_PLUS_10_SECONDS,
+            "value": TEST_DATA_ONE,
+        }
+        result = adapter.load_dict(data=data)
+        assert result.created_at == FIXED_DATETIME_ONE
+        assert result.expires_at == FIXED_DATETIME_ONE_PLUS_10_SECONDS
+
+    def test_dump_json_with_datetime_format_raises_error(self):
+        """Test dump_json raises error when date_format is datetime."""
+        adapter = BasicSerializationAdapter(date_format="datetime")
+        with pytest.raises(SerializationError, match="dump_json is incompatible"):
+            adapter.dump_json(entry=TEST_ENTRY_ONE)
+
+    def test_load_dict_with_string_value(self, adapter: BasicSerializationAdapter):
+        """Test load_dict with value as JSON string."""
+        data = {
+            "created_at": FIXED_DATETIME_ONE_ISOFORMAT,
+            "expires_at": FIXED_DATETIME_ONE_PLUS_10_SECONDS_ISOFORMAT,
+            "value": '{"key": "value"}',
+        }
+        result = adapter.load_dict(data=data)
+        assert result.value == {"key": "value"}
+
+    def test_load_dict_missing_value_raises_error(self, adapter: BasicSerializationAdapter):
+        """Test load_dict raises error when value is missing."""
+        data = {
+            "created_at": FIXED_DATETIME_ONE_ISOFORMAT,
+            "expires_at": FIXED_DATETIME_ONE_PLUS_10_SECONDS_ISOFORMAT,
+        }
+        with pytest.raises(DeserializationError, match="Value field not found"):
+            adapter.load_dict(data=data)
+
+    def test_load_dict_invalid_value_type_raises_error(self, adapter: BasicSerializationAdapter):
+        """Test load_dict raises error when value is not string or dict."""
+        data = {
+            "created_at": FIXED_DATETIME_ONE_ISOFORMAT,
+            "expires_at": FIXED_DATETIME_ONE_PLUS_10_SECONDS_ISOFORMAT,
+            "value": 12345,
+        }
+        with pytest.raises(DeserializationError, match="Value field is not a string or dictionary"):
+            adapter.load_dict(data=data)
+
+
+class TestKeyMustBe:
+    def test_key_missing(self):
+        """Test key_must_be returns None when key is missing."""
+        result = key_must_be({"other": "value"}, key="missing", expected_type=str)
+        assert result is None
+
+    def test_key_wrong_type(self):
+        """Test key_must_be raises TypeError when type is wrong."""
+        with pytest.raises(TypeError, match="created_at must be a str"):
+            key_must_be({"created_at": 12345}, key="created_at", expected_type=str)
+
+    def test_key_correct_type(self):
+        """Test key_must_be returns value when type is correct."""
+        result = key_must_be({"created_at": "2025-01-01"}, key="created_at", expected_type=str)
+        assert result == "2025-01-01"
+
+
+class TestParseDatetimeStr:
+    def test_valid_datetime(self):
+        """Test parse_datetime_str with valid datetime string."""
+        result = parse_datetime_str("2025-01-01T00:00:00+00:00")
+        assert result == FIXED_DATETIME_ONE
+
+    def test_invalid_datetime(self):
+        """Test parse_datetime_str raises error for invalid string."""
+        with pytest.raises(DeserializationError, match="Invalid datetime string"):
+            parse_datetime_str("not-a-datetime")
diff --git a/key-value/key-value-shared/tests/utils/test_time_to_live.py b/key-value/key-value-shared/tests/utils/test_time_to_live.py
index 0f69ee9e..5d6aea28 100644
--- a/key-value/key-value-shared/tests/utils/test_time_to_live.py
+++ b/key-value/key-value-shared/tests/utils/test_time_to_live.py
@@ -5,7 +5,7 @@
 import pytest
 
 from key_value.shared.errors.key_value import InvalidTTLError
-from key_value.shared.utils.time_to_live import prepare_ttl
+from key_value.shared.utils.time_to_live import prepare_entry_timestamps, prepare_ttl, try_parse_datetime_str
 
 FIXED_DATETIME = datetime(2025, 1, 1, 0, 0, 0, tzinfo=timezone.utc)
 
@@ -58,3 +58,49 @@ def test_prepare_ttl(t: Any, expected: int | float | None):
 def test_prepare_ttl_invalid(t: Any):
     with pytest.raises(InvalidTTLError):
         prepare_ttl(t)
+
+
+def test_prepare_ttl_zero():
+    """Test that zero TTL raises InvalidTTLError."""
+    with pytest.raises(InvalidTTLError):
+        prepare_ttl(0)
+
+
+def test_prepare_ttl_negative():
+    """Test that negative TTL raises InvalidTTLError."""
+    with pytest.raises(InvalidTTLError):
+        prepare_ttl(-100)
+
+
+class TestTryParseDatetimeStr:
+    def test_valid_datetime_string(self):
+        """Test parsing valid datetime string."""
+        result = try_parse_datetime_str("2025-01-01T00:00:00+00:00")
+        assert result == FIXED_DATETIME
+
+    def test_invalid_datetime_string(self):
+        """Test parsing invalid datetime string returns None."""
+        result = try_parse_datetime_str("not-a-datetime")
+        assert result is None
+
+    def test_non_string_returns_none(self):
+        """Test non-string values return None."""
+        assert try_parse_datetime_str(12345) is None
+        assert try_parse_datetime_str(None) is None
+        assert try_parse_datetime_str({"key": "value"}) is None
+
+
+class TestPrepareEntryTimestamps:
+    def test_with_ttl(self):
+        """Test prepare_entry_timestamps with a TTL."""
+        created_at, ttl, expires_at = prepare_entry_timestamps(ttl=100)
+        assert ttl == 100.0
+        assert expires_at is not None
+        assert expires_at > created_at
+
+    def test_without_ttl(self):
+        """Test prepare_entry_timestamps without a TTL."""
+        created_at, ttl, expires_at = prepare_entry_timestamps(ttl=None)
+        assert ttl is None
+        assert expires_at is None
+        assert created_at is not None