Abby is an open-source platform designed to help developers manage feature flags, remote configuration, and A/B tests with a statically typed API and an intuitive dashboard for non-technical team members. Built as a monorepo using Turborepo and the T3 Stack, Abby emphasizes developer experience by offering first-class TypeScript support across all its SDKs while ensuring user privacy—no personalized tracking or marketing cookies. It supports self-hosting or using the hosted version at tryabby.com, making it suitable for teams seeking full control over their feature management infrastructure without sacrificing ease of use.
Abby is ideal for development teams using modern JavaScript frameworks like Next.js, React, Angular, or Svelte who want to decouple feature releases from deployments. Its integrated MailHog-based email verification system and self-contained Docker setup make local development frictionless, while its TypeScript-first architecture ensures type safety in feature flag usage across the entire stack.
What You Get
- Static typing for feature flags - All SDKs (React, Next.js, Angular, Svelte) are built on a core TypeScript SDK that provides compile-time type safety for feature flags and A/B tests, reducing runtime errors.
- Self-hostable with Docker - Full infrastructure including database and MailHog email server is defined in docker-compose.yml, enabling secure, private deployment without third-party dependencies.
- Integrated email verification via MailHog - Local development includes a pre-configured MailHog instance at localhost:8025 to intercept and display verification emails during signup.
- Multi-framework SDKs - Official TypeScript SDKs for React, Next.js, Angular, and Svelte ensure seamless integration with popular frontend frameworks without vendor lock-in.
- Developer-friendly dashboard - A clean, non-technical UI for product and marketing teams to manage feature toggles and A/B tests without touching code.
Common Use Cases
- Building a Next.js app with dynamic feature flags - Developers use the Abby Next.js SDK to enable or disable features based on user segments without redeploying, ideal for staging new UI components in production.
- Running privacy-compliant A/B tests - Teams run experiments on button colors or layouts without collecting personal data, meeting GDPR and CCPA requirements by design.
- Problem: Feature deployments causing production bugs → Solution: Abby - Developers toggle features off via the dashboard during incidents, eliminating the need for rollback deployments and reducing mean time to recovery.
- Team workflow: Devs + PMs collaborating on releases - Engineers implement flags using TypeScript SDKs, while product managers adjust targeting rules in the dashboard—no engineering tickets required for simple toggles.
Under The Hood
Tryabby Abby is a feature flag and experimentation platform designed for developers, offering unified tools for remote configuration, A/B testing, and user segmentation. It provides a cohesive developer experience across multiple frontend frameworks with a modular architecture that supports extensibility and seamless integration.
Architecture
The project adopts a monorepo structure that enables modular development across distinct applications such as a CDN, documentation site, and web app. This organization promotes shared dependencies and consistent configuration while maintaining clear separation of concerns.
- Monorepo design allows for shared logic and streamlined development across multiple apps
- Modular application structure supports independent scaling and maintenance of components
- Strong emphasis on separation of concerns between frontend, backend, and infrastructure layers
Tech Stack
The tech stack is built on modern TypeScript with a focus on developer experience and performance, leveraging industry-standard tools for full-stack development.
- TypeScript as the primary language ensures type safety and improved developer productivity
- Next.js powers the web application, while Hono handles lightweight server-side logic
- Prisma, Sentry, and @tryabby libraries form the core of backend and integration capabilities
- Turbo, pnpm, and Vite support efficient monorepo management and fast development workflows
Code Quality
The codebase reflects a solid commitment to testing, maintainability, and consistent style, with practices that support long-term reliability.
- Comprehensive test coverage across API endpoints and core modules ensures robust functionality
- Error handling is consistently applied using structured try/catch patterns in critical areas
- Code style and conventions align with TypeScript best practices, promoting readability and consistency
- Some technical debt is present, indicating opportunities for abstraction and refactoring
What Makes It Unique
Tryabby Abby distinguishes itself through its unified approach to feature flags and experimentation, tailored for modern frontend ecosystems.
- Modular monorepo design enables shared core logic across web, CDN, and documentation apps with clean architectural boundaries
- Extensive framework-specific integrations (Next.js, React, Angular, Svelte) deliver tailored developer experiences
- Built-in A/B testing and user segmentation capabilities remove the need for external tools or complex infrastructure setup
- Rich documentation and reference examples facilitate rapid adoption and extension by developers