hexastack-flags

CNCF OpenFeature provider adapters and enterprise feature flagging for Hexastack.

Part of the Hexastack Framework.

1. Architectural Overview

hexastack-flags provides the production-grade adapter connecting Hexastack's FeatureFlagPort to the CNCF OpenFeature Python SDK.

It decouples your domain, CQRS handlers, REST routes, Typer commands, and GraphQL resolvers from proprietary feature flagging APIs, allowing seamless integration with Flagd, Unleash, Flipt, GO Feature Flag, or local in-memory providers.

graph TD
    APP["Driving Adapters (FastAPI / CLI / GraphQL)"]
    CQRS["CQRS Middleware Pipeline"]
    PORT["FeatureFlagPort (hexastack-core)"]
    ADAPTER["OpenFeatureFlagAdapter (hexastack-flags)"]
    OF_SDK["CNCF OpenFeature SDK"]

    subgraph Providers ["OpenFeature Providers"]
        FLAGD["FlagdProvider (gRPC / Kubernetes)"]
        UNLEASH["UnleashProvider"]
        MEM["InMemoryProvider"]
        ENV["EnvProvider"]
    end

    APP --> PORT
    CQRS --> PORT
    PORT -.-> ADAPTER
    ADAPTER --> OF_SDK
    OF_SDK --> FLAGD
    OF_SDK --> UNLEASH
    OF_SDK --> MEM
    OF_SDK --> ENV

2. Quickstart

Installation

# Core OpenFeature adapter with In-Memory support
pip install hexastack-flags

# With Flagd provider
pip install "hexastack-flags[flagd]"

Configuration (hexastack.toml or pyproject.toml)

[hexastack.flags]
provider = "flagd" # "in_memory", "flagd", "env"
host = "localhost"
port = 8013
cache = true
timeout_ms = 5000

3. Evaluation Examples

from hexastack_core.ports.feature_flags import FeatureFlagPort
from hexastack_core.domain.feature_flags import EvaluationContext

flags = container.resolve(FeatureFlagPort)

# 1. Simple boolean toggle
if flags.is_enabled("features.checkout.v2", default=False):
    ...

# 2. Contextual evaluation (multi-tenant / user targeting)
ctx = EvaluationContext(user_id="usr_123", tenant_id="tenant-alpha")
theme = flags.get_string_value("features.ui.theme", default="light", context=ctx)