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Flags SDK
The feature flags toolkit for Next.js and SvelteKit

Flags SDK
Free

Home: https://flags-sdk.dev

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Flags SDK

What is Flags SDK?

Flags SDK provides a comprehensive toolkit for implementing feature flags in modern web frameworks like Next.js and SvelteKit. It offers a server-side approach that ensures consistent flag evaluation and eliminates client-side loading spinners, making it ideal for A/B testing and controlled feature rollouts. The SDK sits between applications and flag sources, helping developers follow best practices while maintaining website performance.

With support for multiple providers including Vercel, Statsig, Hypertune, and GrowthBook, Flags SDK offers flexible integrations without locking users into specific services. Its declarative API simplifies flag definition and usage, enabling strategic releases and experimentation with confidence across App Router, Pages Router, and Routing Middleware environments.

Features

  • Server-side Evaluation: Ensures consistent flag evaluation without client-side loading spinners
  • Provider Flexibility: Works with any flag provider including Vercel, Statsig, Hypertune, and GrowthBook
  • Framework Integration: Seamlessly integrates with Next.js App Router, Pages Router, and Routing Middleware
  • Declarative API: Simple API for defining and using feature flags with minimal configuration
  • A/B Testing Support: Built-in capabilities for experimentation and controlled rollouts

Use Cases

  • Implementing feature flags for controlled feature releases in web applications
  • Conducting A/B testing experiments on website elements and functionality
  • Managing feature rollouts across different user segments or environments
  • Testing new features in production without affecting all users
  • Creating dynamic user experiences based on flag configurations

FAQs

  • What frameworks does Flags SDK support?
    Flags SDK supports Next.js and SvelteKit frameworks with integration for App Router, Pages Router, and Routing Middleware.
  • Does Flags SDK require a specific flag provider?
    No, Flags SDK works with any flag provider including Vercel, Statsig, Hypertune, GrowthBook, and others, or can be used without any provider.
  • Is Flags SDK free to use?
    Yes, Flags SDK is completely free and open-source with no subscription fees.
  • How does Flags SDK handle flag evaluation?
    Flags SDK uses server-side evaluation to ensure consistent flag behavior and eliminate client-side loading spinners.
  • What are the main use cases for Flags SDK?
    Flags SDK is ideal for A/B testing, controlled feature rollouts, experimentation, and managing feature releases in production environments.

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