openfeature-flagd-api

What it is and what it does

This package provides the pure API contract—a Python Protocol—that defines what a flagd evaluator must implement to work with the OpenFeature SDK. It is a lightweight interface definition rather than a working implementation, intended for developers who want to create custom evaluators for the flagd provider. The package depends only on openfeature-sdk and is part of the OpenFeature Python SDK contrib project, mirroring the Java flagd-api module.

You install it when you need to build your own evaluator implementation that conforms to the flagd contract. It establishes the protocol boundary between the OpenFeature framework and custom evaluation logic, allowing third-party code to plug in without modifying the core SDK.

Use it for:

• Building a custom flagd evaluator implementation that integrates with the OpenFeature SDK.
• Defining type-safe contracts for feature flag evaluation in a larger OpenFeature architecture.
• Creating a domain-specific evaluator that implements the Evaluator protocol for specialized flag resolution logic.
• Extending the OpenFeature ecosystem with evaluators that handle flagd-compatible feature flag formats.

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

Defines the Python Protocol contract for flagd evaluators, allowing custom implementations to integrate with the OpenFeature SDK.

Yes, if you are building a custom flagd evaluator for OpenFeature. This is a pure contract package with no vulnerabilities, permissive licensing, and active maintenance. Install only if you need to implement the Evaluator protocol; it is not a standalone tool but a dependency for evaluator development.

Install

openfeature-flagd-api on PyPI

pip install openfeature-flagd-api

uv add openfeature-flagd-api

poetry add openfeature-flagd-api

Installing openfeature-flagd-api

Before you install

Low install friction with a single runtime dependency on openfeature-sdk. Actively maintained as of 2026-08-12 with recent activity.

License in practice

Apache 2.0 permissive license allows commercial and private use, modification, and distribution with minimal restrictions—only requiring license and copyright notice preservation.

Quickstart

pip install openfeature-flagd-api

from openfeature.contrib.tools.flagd.api import Evaluator, FlagStoreException

# Implement the Evaluator protocol for custom evaluator

Requires Python 3.10 or later.

Verify before relying

• Whether the package includes concrete example implementations or reference evaluators beyond the protocol definition.
• API stability guarantees or semantic versioning policy for the protocol contract.
• Integration testing guidance or compatibility matrix with specific flagd versions.

Package facts

Evidence: openfeature_flagd_api-1.0.0-py3-none-any.whl

Tags

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