Web applications
Updated on October 27, 2026
Web Applications
When you deploy from GitHub, the auto builder inspects your repository's contents to automatically choose the runtime, and the install and build commands, with no configuration file to write on your end.
Recognized runtimes
More than 35 frameworks are automatically detected, each with its own start command. The full list, detection signals, and generated commands are on Supported frameworks. The main families:
| Family | Examples | Guide |
|---|---|---|
| Fullstack & SSR | Next.js, Nuxt, SvelteKit, Remix, Astro, RedwoodJS, SolidStart, Qwik… | Supported frameworks |
| Node.js backend | Express, Fastify, NestJS, Koa, AdonisJS, FeathersJS, Moleculer… | Node.js |
| Static frontend | Vite (React / Vue / Svelte), Gatsby, Gulp | React / Vite |
| Python | Django, FastAPI, Flask | Python |
| PHP | Laravel, composer.json | PHP |
| Other languages | Go, Ruby on Rails, Rust, Deno | Go |
If your repository contains a Dockerfile, it always takes precedence over automatic detection (see Docker).
What's common to all stacks
- Your application must read the
PORTvariable and listen on0.0.0.0, never onlocalhost. - Any key, password, or connection URL is configured via environment variables, never hardcoded in the repository.
- A web service's filesystem is ephemeral. Any data that needs to be kept must go through a database.
- The start command can always be manually overridden, see Custom start command.
Each stack guide above details the exact commands run by the auto builder and the environment variables specific to the framework.