OpenNext is an open-source adapter that transforms Next.js build output into deployable packages optimized for AWS environments. Written in TypeScript, the project converts Next.js applications to run natively on AWS Lambda and classic Node.js servers, enabling developers to leverage serverless infrastructure for their React-based applications. The project is maintained by SST and documented at opennext.js.org.
The adapter supports a comprehensive set of Next.js 15 features including both App and Pages Router, API routes, dynamic routes, static site generation, server-side rendering, incremental static regeneration, middleware, server actions, and image optimization. It includes built-in support for NextAuth.js authentication and edge runtime execution. A notable feature is the implementation of a warmer function designed to minimize Lambda cold starts, addressing a common performance challenge in serverless deployments where additional requests or lazy-loaded routes can trigger cold starts even with pre-warmed instances.
Configuration is handled through an optional open-next.config.ts file placed alongside next.config.js, allowing developers to customize deployment behavior. The project includes a debug mode activated via the OPEN_NEXT_DEBUG environment variable that provides extensive logging and source maps, though it increases build size significantly and is not recommended for production use. Beyond standard npm releases, the project publishes prerelease packages automatically on branch pushes through pkg.pr.new, with a main branch prerelease representing stable development versions and an experimental branch prerelease for testing new features before wider release.
Common issue labels include need reproduction, help wanted, and enhancement requests.
Notable adopters include Gymshark UK, Udacity, TUDN, and NHS England, demonstrating production-ready deployment across various scales. The project provides comprehensive development documentation and maintains an active Discord community for support. Local development is supported through watch mode builds and a dedicated local run guide for debugging purposes. Testing infrastructure includes both unit tests and end-to-end tests that can be executed locally, supporting the project's commitment to code quality and reliability in serverless Next.js deployments.
