Storage Backends

litestar-flags supports multiple storage backends for different deployment scenarios.

Memory Backend

The MemoryStorageBackend stores flags in memory. This is the default backend and is ideal for:

• Development and testing

• Single-instance deployments

• Prototyping

Warning

Flags stored in memory are lost when the application restarts.

from litestar_flags import FeatureFlagsConfig
from litestar_flags.storage import MemoryStorageBackend

config = FeatureFlagsConfig(
    storage_backend=MemoryStorageBackend(),
)

Redis Backend

The RedisStorageBackend stores flags in Redis, enabling:

• Distributed flag storage across multiple instances

• Flag persistence across restarts

• Real-time flag synchronization

Requirements

Install the Redis extra:

uv (Recommended)

uv add litestar-flags[redis]

pip

pip install litestar-flags[redis]

Configuration

from litestar_flags import FeatureFlagsConfig
from litestar_flags.storage import RedisStorageBackend

backend = RedisStorageBackend(
    url="redis://localhost:6379/0",
    prefix="myapp:flags:",  # Key prefix for namespacing
)

config = FeatureFlagsConfig(storage_backend=backend)

Database Backend

The DatabaseStorageBackend provides persistent storage using SQLAlchemy, supporting:

• PostgreSQL, MySQL, SQLite, and other databases

• Full ACID compliance

• Integration with existing database infrastructure

Requirements

Install the database extra:

uv (Recommended)

uv add litestar-flags[database]

pip

pip install litestar-flags[database]

Configuration

from litestar_flags import FeatureFlagsConfig
from litestar_flags.storage import DatabaseStorageBackend

backend = DatabaseStorageBackend(
    connection_string="postgresql+asyncpg://user:pass@localhost/mydb",
)

config = FeatureFlagsConfig(storage_backend=backend)

Choosing a Backend

Feature	Memory	Redis	Database
Persistence	No	Yes	Yes
Multi-instance	No	Yes	Yes
Real-time sync	N/A	Yes	No
Setup complexity	None	Low	Medium
Best for	Development	Production	Production

Custom Backends

You can create custom storage backends by implementing the StorageBackend abstract base class:

from litestar_flags.storage import StorageBackend
from litestar_flags import FeatureFlag

class MyCustomBackend(StorageBackend):
    async def get(self, name: str) -> FeatureFlag | None:
        # Implement flag retrieval
        ...

    async def set(self, flag: FeatureFlag) -> None:
        # Implement flag storage
        ...

    async def delete(self, name: str) -> None:
        # Implement flag deletion
        ...

    async def list(self) -> list[FeatureFlag]:
        # Implement listing all flags
        ...