Client API overview

The Client API is designed for backend SDKs and Unleash Edge to fetch feature flag configurations. This API returns all feature flags and activation strategies for server-side evaluation.

Base path: <your-unleash-url>/api/client

Primary use: Backend services fetch complete flag configurations to evaluate flags server-side with full activation strategy logic and constraints.

Authentication

Use backend tokens for authentication. These tokens can be scoped to specific projects and environments. Backend tokens must remain secret and should never be exposed in client-side code.

To create a backend token, go to Admin settings > Access control > API access > New API token

Available endpoints

Using with Unleash Edge

Unleash Enterprise Edge uses the Client API to stay synchronized with your Unleash instance. Edge provides:

• Reduced latency for distributed applications.
• Built-in caching and fallback.
• Lower load on your main Unleash instance.
• Frontend API endpoint support.