## Description
OpenNext takes the Next.js build output and converts it into packages that can be deployed across a variety of environments. Natively OpenNext has support for AWS Lambda, and classic Node.js Server.
## Features
OpenNext aims to support all Next.js 15 features. Some features are work in progress. If you are running into any problems make sure to check the [docs](https://opennext.js.org/aws) first before you open a [new issue](/issues/new) or visit our [Discord](https://discord.gg/opennextjs) to let us know!
- [x] App & Pages Router
- [x] API routes
- [x] Dynamic routes
- [x] Static site generation (SSG)
- [x] Server-side rendering (SSR)
- [x] Incremental static regeneration (ISR)
- [x] Middleware
- [x] Server actions
- [x] Image optimization
- [x] [NextAuth.js](https://next-auth.js.org)
- [x] Running at edge
- [x] [Almost no coldstart (\*)](#coldstart)
## Who is using OpenNext?
[Gymshark UK](https://uk.gymshark.com), [Udacity](https://engineering.udacity.com/deploying-next-js-on-the-edge-with-sst-is-sst-the-game-changer-its-claimed-to-be-1f05a0abc27c), [TUDN](https://www.tudn.com), [NHS England](https://github.com/nhs-england-tools/terraform-aws-opennext)
## Configuration
### Configuration file
For personalisation you need to create a file `open-next.config.ts` at the same place as your `next.config.js`, and export a default object that satisfies the `OpenNextConfig` interface. It is possible to not have an open-next.config.ts file, the default configuration will then be applied automatically.
### Debug mode
OpenNext can be executed in debug mode by setting the environment variable `OPEN_NEXT_DEBUG=true` before your build.
This will output A LOT of additional logs to the console. This also disable minifying in esbuild, and add source maps to the output. This can result in code that might be up to 2-3X larger than the production build. Do **not** enable this in production.
You can read more about the configuration in the [docs](https://opennext.js.org/aws/config)
## Preleases
Besides the standard npm releases we also automatically publish prerelease packages on branch pushes (using [`pkg.pr.new`](https://github.com/stackblitz-labs/pkg.pr.new)):
- `https://pkg.pr.new/@opennextjs/aws@main`:
Updated with every push to the `main` branch, this prerelease contains the most up to date yet (reasonably) stable version of the package.
- `https://pkg.pr.new/@opennextjs/aws@experimental`
Updated with every push to the `experimental` branch, this prerelease contains the latest experimental version of the package (containing features that we want to test/experiment on before committing to).
Which you can simply install directly with your package manager of choice, for example:
```bash
npm i https://pkg.pr.new/@opennextjs/aws@main
```
## Contribute
To run `OpenNext` locally:
1. Clone this repository.
1. Build `open-next`:
```bash
cd packages/open-next
pnpm build
```
1. Run `open-next` in watch mode:
```bash
pnpm dev
```
1. Now, you can make changes in `open-next` and build your Next.js app to test the changes.
```bash
cd path/to/my/nextjs/app
path/to/opennextjs-aws/packages/open-next/dist/index.js build
```
There is also a way to run OpenNext locally. You can read a guide about it [here](https://opennext.js.org/aws/contribute/local_run). Its mostly used for development/debugging purposes.
## Testing
You can run unit tests with
```bash
pnpm test
```
You can tun e2e locally with:
```bash
pnpm -r openbuild:local
pnpm -r openbuild:local:start
```
And in a different shell:
```bash
pnpm e2e:test
```
## Coldstart
OpenNext provide you with a warmer function that can be used to reduce cold start.
On Lambda, there are multiple scenarios where a lambda will trigger a cold start even if you have some warmed instance. For example if you have more requests than warm instances you'll get a cold start. Also NextJs lazy load the routes, so even if you hit a warm instance, this specific route might not have been loaded yet.
## Acknowledgements
We are grateful for the projects that inspired OpenNext and the amazing tools and libraries developed by the community:
- [nextjs-lambda](https://github.com/sladg/nextjs-lambda) by [Jan](https://github.com/sladg) for serving as inspiration for packaging Next.js's standalone output to Lambda.
- [CDK NextJS](https://github.com/jetbridge/cdk-nextjs/) by [JetBridge](https://github.com/jetbridge) for its contribution to the deployment architecture of a Next.js application on AWS.
- [serverless-http](https://github.com/dougmoscrop/serverless-http) by [Doug Moscrop](https://github.com/dougmoscrop) for developing an excellent library for transforming AWS Lambda events and responses.
- [serverless-nextjs](https://github.com/serverless-nextjs/serverless-next.js) by [Serverless Framework](https://github.com/serverless) for paving the way for serverless Next.js applications on AWS.
Special shoutout to [@khuezy](https://github.com/khuezy) and [@conico974](https://github.com/conico974) for their outstanding contributions to the project.
---
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