---
id: yggdrasil-engine
version: "1.3.1"
license: MIT
license_treatment: permissive
maintenance: active
---

# yggdrasil-engine — Engine for evaluating Unleash feature flags

License: permissive · Maintenance: active · Downloads: 2.1M/mo

## What it is and what it does

yggdrasil-engine is a Python wrapper around the Unleash Yggdrasil native engine, which evaluates feature flags and toggles. It bridges Python code to a high-performance Rust-based evaluation engine, allowing applications to make feature flag decisions at runtime.

The package is built as compiled wheels for multiple platforms and Python versions (3.8 through 3.12), with no external Python dependencies. It's designed for teams using Unleash as their feature management platform and need to evaluate flags from Python applications. The underlying native library version is managed separately during the build process.

Use it for:

- Evaluate feature flags in Python web applications to control feature rollouts and A/B tests
- Gate new functionality behind flags in backend services to enable safe deployment and gradual rollout
- Implement feature experiments where different user cohorts see different behavior based on flag state
- Integrate feature flag evaluation into Python microservices that use Unleash for centralized flag management

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Provides Python bindings to the Unleash Yggdrasil engine for evaluating feature flags in applications.

Yes, if you are using Unleash for feature management and need to evaluate flags from Python. The package is actively maintained, has no known vulnerabilities, carries a permissive MIT license, and supports current Python versions. Medium install friction is typical for compiled packages and poses no practical barrier on standard platforms.

## Install

pip install yggdrasil-engine
uv add yggdrasil-engine
poetry add yggdrasil-engine

## Installing yggdrasil-engine

Before you install: Medium install friction due to compiled wheels across multiple platforms (macOS, Linux, Windows, ARM architectures). Active maintenance with a release within the last 51 days. No runtime dependencies to manage.

License in practice: MIT license permits use in commercial and proprietary projects with minimal restrictions; attribution required.

Quickstart:

pip install yggdrasil-engine

import yggdrasil_engine
# Use the engine to evaluate feature flags

Requires Python 3.8 or later; prebuilt wheels available for common platforms (x86_64, ARM64 on macOS, Linux, Windows).

Verify before relying:

- Whether the package requires initialization with Unleash configuration or context before evaluating flags
- Performance characteristics and typical evaluation latency for feature flag decisions
- Whether offline/local flag evaluation is supported or if it requires network connectivity

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: medium
- Maintenance: active
- Downloads: 2.1M/month (top 5,000 on PyPI)
- Known vulnerabilities: none known

## Tags

feature flag evaluation, unleash yggdrasil bindings, python feature flags, feature toggle engine, flag evaluation library, unleash sdk python, feature management, feature-flags, unleash, feature-management

[View on SkillFed](https://skillfed.io/packages/yggdrasil-engine) · [View on PyPI](https://pypi.org/project/yggdrasil-engine/)