OpenFeature Provider for Flagsmith

0.1.6 · active · verified Fri Apr 17

The `openfeature-provider-flagsmith` library provides an OpenFeature-compliant provider for Flagsmith. It allows applications to integrate Flagsmith's feature flag capabilities using the OpenFeature SDK, abstracting the underlying feature flagging system. The current version is 0.1.6, with releases typically tied to updates in OpenFeature SDK or Flagsmith SDK, or feature enhancements.

Common errors

```
ModuleNotFoundError: No module named 'openfeature_provider_flagsmith'
```
cause The `openfeature-provider-flagsmith` library has not been installed in the current Python environment.

fix Run `pip install openfeature-provider-flagsmith`.
```
TypeError: FlagsmithProvider.__init__ missing 1 required positional argument: 'environment_key'
```
cause The `environment_key` argument, which is your Flagsmith environment's unique key, was not provided during the instantiation of `FlagsmithProvider`.

fix Pass your Flagsmith Environment Key: `provider = FlagsmithProvider(environment_key="YOUR_FLAGSMITH_ENVIRONMENT_KEY")`.
```
flagsmith.exceptions.FlagsmithAPIError: Network Error ...
```
cause The `flagsmith` SDK failed to connect to the Flagsmith API due to network issues, an incorrect API key, or an invalid base URL (if customized).

fix Verify your internet connection, ensure the `environment_key` is correct, and check if the Flagsmith API is reachable. If you're self-hosting Flagsmith, confirm your `api_url` parameter is correctly configured (not shown in quickstart, but an option for `FlagsmithProvider`).

Warnings

gotcha The `environment_key` is a mandatory argument for `FlagsmithProvider`. Failure to provide a valid key will lead to errors during initialization or feature flag evaluation.
Fix: Always provide your Flagsmith Environment Key during `FlagsmithProvider` instantiation: `FlagsmithProvider(environment_key="YOUR_KEY")`.
gotcha The provider relies on network connectivity to the Flagsmith API. Issues like network timeouts or incorrect API endpoints (if customized) can prevent feature flags from being resolved.
Fix: Ensure your application has stable network access to the Flagsmith API. Check your Flagsmith project configuration and API status if you encounter network-related errors. Consider using `OpenFeatureAPI.set_default_value` for robust fallback behavior.
gotcha The OpenFeature `get_value` methods (e.g., `get_boolean_value`) require a default value. This default is returned if the flag is not found in Flagsmith, if the provider is not configured correctly, or if an error occurs during evaluation.
Fix: Always provide a sensible and safe default value that ensures your application can function even if the feature flag cannot be resolved correctly. E.g., `client.get_boolean_value("my_flag", False)`.
deprecated The `flagsmith` SDK dependency has minimum version `4.0.0` and maximum `5.x.x` (i.e., `<6.0.0`). Newer versions of the `flagsmith` SDK (e.g., `6.x.x`) may introduce breaking changes not yet supported by this provider.
Fix: Strictly adhere to the `flagsmith` SDK version range specified by `openfeature-provider-flagsmith`'s `install_requires`. Upgrade `openfeature-provider-flagsmith` if you need to use a newer `flagsmith` SDK version.

Install

pip install openfeature-provider-flagsmith Install latest version

Imports

FlagsmithProvider

wrong:

from openfeature_provider_flagsmith.provider import FlagsmithProvider

correct:

from openfeature_provider_flagsmith import FlagsmithProvider

The FlagsmithProvider class is directly available at the top level of the package.

OpenFeatureAPI
```
from openfeature import OpenFeatureAPI
```
This is part of the core OpenFeature SDK, not the Flagsmith provider itself.

Quickstart

This quickstart demonstrates how to initialize the `FlagsmithProvider` with your Flagsmith Environment Key, register it with the OpenFeature API, and then use the OpenFeature client to evaluate boolean and string feature flags. Ensure your `FLAGSMITH_ENVIRONMENT_KEY` is set as an environment variable.

import os
from openfeature import OpenFeatureAPI
from openfeature_provider_flagsmith import FlagsmithProvider

# Ensure you have your Flagsmith Environment Key set as an environment variable
# Or replace os.environ.get() with your actual key directly (not recommended for production)
FLAGSMITH_ENVIRONMENT_KEY = os.environ.get("FLAGSMITH_ENVIRONMENT_KEY", "")

if not FLAGSMITH_ENVIRONMENT_KEY:
    print("Error: FLAGSMITH_ENVIRONMENT_KEY environment variable not set.")
    print("Please set it to your Flagsmith Environment Key to run this example.")
else:
    # 1. Initialize the Flagsmith Provider
    provider = FlagsmithProvider(environment_key=FLAGSMITH_ENVIRONMENT_KEY)

    # 2. Set the provider globally for OpenFeature
    OpenFeatureAPI.set_provider(provider)

    # 3. Get an OpenFeature client
    client = OpenFeatureAPI.get_client()

    # 4. Evaluate a feature flag (assuming 'my_boolean_flag' exists in Flagsmith)
    # Provide a default value (False) in case the flag is not found or an error occurs
    is_feature_enabled = client.get_boolean_value("my_boolean_flag", False)

    print(f"Feature 'my_boolean_flag' is enabled: {is_feature_enabled}")

    # Example with a string flag
    welcome_message = client.get_string_value("welcome_message", "Hello, World!")
    print(f"Welcome message: {welcome_message}")

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