UnleashClient
Python client for the Unleash feature toggle system!
What it is and what it does
UnleashClient is a Python SDK that connects your application to Unleash, a feature management platform designed to control feature rollouts and reduce release risk. It lets you evaluate feature flags and variants at runtime, with support for gradual rollouts, user segmentation via context, and custom activation strategies. The SDK runs on the server side and handles synchronization with the Unleash API, caching, metrics reporting, and scheduled background updates.
The package integrates with APScheduler for background synchronization and uses requests for HTTP communication. It supports fallback functions for graceful degradation when flags are unavailable, context-based evaluation (userId, sessionId, custom properties), and both on-disk and custom cache implementations. The SDK is production-ready (Development Status 5), actively maintained, and supports Python 3.8 through 3.13.
Use it for:
- Gradually roll out new features to a subset of users to validate before full release.
- Toggle experimental features on or off without redeploying your application.
- Run A/B tests by evaluating different feature variants based on user context.
- Implement feature flags for canary deployments or blue-green release strategies.
- Disable problematic features in production without a code change or restart.
Worth the install?
AI-flagged interpretation of the facts on this page — verify before relying
A server-side Python SDK for integrating with Unleash, a feature management platform, to evaluate feature flags and control feature rollouts in your application.
Yes. The package is actively maintained, has low install friction, carries no known vulnerabilities, and uses a permissive MIT license. It's well-suited for any Python application that needs feature flag management. The main consideration is ensuring your Unleash server is configured and accessible before initializing the client, as feature flags default to false until synchronized.
Install
unleashclient on PyPI
pip
pip install unleashclientuv
uv add unleashclientpoetry
poetry add unleashclientInstalling UnleashClient
Before you install
Low install friction with a pure Python wheel distribution. The package is actively maintained with a recent release (24 days old) and supports modern Python versions (3.8–3.13). Nine runtime dependencies are manageable and well-established.
License in practice
Licensed under MIT (permissive), so you can use, modify, and distribute this package with minimal legal constraints.
Quickstart
pip install UnleashClient
from UnleashClient import UnleashClient
client = UnleashClient(
url="https://your-unleash-url",
app_name="my-app",
custom_headers={'Authorization': 'your-token'})
client.initialize_client()
enabled = client.is_enabled("my_toggle")
variant = client.get_variant("variant_toggle")
client.destroy()
The SDK must be initialized and synchronized with the Unleash API before feature flags will evaluate correctly; until then, all features default to false unless you provide a fallback function or bootstrap configuration.
Verify before relying
- Whether custom strategies and the features property migration path in v6 affects typical use cases or only advanced deployments.
- Performance characteristics when evaluating large numbers of feature flags or handling high-frequency context changes.
Package facts
| License | not declared (permissive) |
| Python support | supports the current Python release (>=3.8) |
| Install friction | low — pure-Python wheel |
| Runtime dependencies | 9 — requests, fcache, mmh3, apscheduler, importlib_metadata, python-dateutil, semver, yggdrasil-engine, launchdarkly-eventsource |
| Maintenance | actively maintained — 24 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 2,517,340/month — #3,028 on PyPI (30-day window, as of 2026-08-14) |
| Known vulnerabilities | none known (OSV.dev, checked 2026-08-14) |
Evidence: unleashclient-6.8.0-py3-none-any.whl
Tags
More Software Development packages
Provides backported and experimental type hints…
permissive · top 100 on PyPI
numpyNumPy provides an N-dimensional array object…
permissive · top 100 on PyPI
fastapiFastAPI is a Python web framework for building…
permissive · top 100 on PyPI
annotated-docProvides a way to document function parameters,…
permissive · top 100 on PyPI
typerTyper builds command-line applications from…
permissive · top 1,000 on PyPI
distlibDistlib provides low-level packaging utilities…
permissive · top 1,000 on PyPI
harness-featureflagsPython SDK for evaluating and managing feature…
permissive · top 15,000 on PyPI
openfeature-provider-unleashIntegrates Unleash feature flags with…
permissive · top 15,000 on PyPI
yggdrasil-engineProvides Python bindings to the Unleash…
permissive · top 5,000 on PyPI
flagsmithFlagsmith is a Python SDK for managing feature…
permissive · top 5,000 on PyPI
launchdarkly-server-sdkA server-side SDK for integrating…
permissive · top 5,000 on PyPI
configcat-clientA Python SDK for integrating ConfigCat's…
permissive · top 5,000 on PyPI
django-flagsDjango-Flags provides a feature flag system for…
permissive · top 15,000 on PyPI
amplitude-experimentProvides server-side A/B testing and feature…
permissive · top 15,000 on PyPI
statsigStatsig is a Python server SDK for managing…
permissive · top 5,000 on PyPI
django-waffleDjango Waffle provides feature flags (toggles)…
permissive · top 5,000 on PyPI