Flagcel OpenFeature Provider for Python

OpenFeature provider for Flagcel with local CEL evaluation. The provider polls Flagcel for evaluation definitions, compiles rules with cel-expr-python, and evaluates flags in-process.

python -m pip install flagcel-openfeature

from openfeature import api
from openfeature.evaluation_context import EvaluationContext
from flagcel_openfeature import FlagcelProvider

provider = FlagcelProvider(
    endpoint="http://localhost:8080/api/v1",
    api_key="fc_example_secret",
)
api.set_provider(provider)

client = api.get_client("checkout-service")
enabled = client.get_boolean_value(
    "new-checkout",
    False,
    EvaluationContext(
        targeting_key="u_123",
        attributes={"user": {"id": "u_123", "country": "US"}},
    ),
)

Behavior

• Requires Python 3.11+.
• Fetches GET /eval/definitions relative to the configured endpoint.
• Sends Authorization: Bearer <api_key> when an API key is configured; the API key selects the evaluation environment.
• Polls definitions every 30 seconds by default.
• Uses ETag and If-None-Match to avoid reloading unchanged definitions.
• Evaluates flags locally with CEL expressions from the latest definitions.
• Returns OpenFeature defaults with provider-not-ready details if no definitions have loaded.
• Keeps using last-known definitions after later refresh failures.
• Maps Flagcel reason, variant, and value type into OpenFeature resolution details.

Configure the polling interval in seconds:

provider = FlagcelProvider(
    endpoint="http://localhost:8080/api/v1",
    api_key="fc_example_secret",
    poll_interval=10.0,
)