foff 0.1.0

Python SDK for FOFF Feature Config service

FOFF Feature Config Python SDK

Python SDK for the FOFF Feature Config service. Provides both sync and async clients with built-in caching and background polling.

Installation

pip install foff

Quick Start

Sync Client

from foff import Client, Config

config = Config(
    api_key="your-api-key",
    base_url="https://foff.twospoon.ai/live",
    scope="production",
    polling_interval=30,  # refresh configs every 30 seconds (0 to disable)
)

with Client(config) as client:
    value = client.get_feature_config("dark_mode", ["prod", "us-east", "acme"])
    print(value)  # e.g. {"enabled": True, "beta": True}

Async Client

import asyncio
from foff import AsyncClient, Config

config = Config(
    api_key="your-api-key",
    base_url="https://foff.twospoon.ai/live",
    scope="production",
    polling_interval=30,
)

async def main():
    async with AsyncClient(config) as client:
        value = client.get_feature_config("dark_mode", ["prod", "us-east", "acme"])
        print(value)

asyncio.run(main())

Configuration

Parameter	Type	Required	Default	Description
api_key	str	Yes		API key for authentication
base_url	str	Yes		Base URL of the FOFF service
scope	str	Yes		Scope identifier for your configs
polling_interval	int	No	30	Polling interval in seconds (0 disables polling)

Feature Lookup

value = client.get_feature_config(feature_name, ordered_hierarchy)

• feature_name — the name of the feature flag
• ordered_hierarchy — a list of hierarchy levels from broadest to most specific

The SDK resolves configs from most specific to least specific. Given ["prod", "us-east", "acme"], it checks:

1. prod#us-east#acme
2. prod#us-east
3. prod
4. default

Returns the first match, or None if the feature doesn't exist.

Client Lifecycle

Sync

The Client constructor performs a blocking initial fetch. If the fetch fails, an exception is raised and no resources are leaked.

# Context manager (recommended)
with Client(config) as client:
    ...

# Manual
client = Client(config)
try:
    ...
finally:
    client.close()

Async

The AsyncClient constructor is lightweight — no network calls. Call start() or use async with to initialize.

# Context manager (recommended)
async with AsyncClient(config) as client:
    ...

# Manual
client = AsyncClient(config)
await client.start()
try:
    ...
finally:
    await client.close()

Background Polling

When polling_interval > 0, the client refreshes configs in the background. Polling errors are silently ignored — the client continues serving the last successfully fetched configs.

Call close() (or exit the context manager) to stop polling and release resources.

Development

pip install -e ".[dev]"
pytest tests/

Contributing

License

See LICENSE.