Hosting

Frameworks and runtimes

What Rimbra detects, the command it runs for each language, and what your app needs to start.

The one rule for servers

If your app is a server, listen on the port in the PORT environment variable. Rimbra picks the port, sets PORT, and routes your domain to it.

js / python

// Node.js
const port = process.env.PORT || 3000
app.listen(port)

# Python
port = int(os.environ.get("PORT", 8000))

Your files	Detected as	How it runs
package.json with next	Next.js	Builds, then runs the Next.js server
Vite, Astro, SvelteKit, Nuxt config	Frontend framework	Builds and serves the output
index.html	Static site	Served as files
package.json with a start script or server.js	Node server	npm start, or node on your entry file
requirements.txt or pyproject.toml	Python	Uvicorn for FastAPI, Gunicorn for Flask, runserver for Django
composer.json or index.php	PHP	PHP serving public/ or the project root
go.mod	Go	go build, then runs the binary
Cargo.toml	Rust	cargo build --release, then runs the binary
Gemfile with config.ru	Ruby	bundle exec rackup
pom.xml or build.gradle	Java	Maven package or Gradle bootJar, then java -jar
Dockerfile	Container	Builds the image and runs it with PORT set

List dependencies in requirements.txt or pyproject.toml.
Put your app in main.py, app.py, server.py or run.py, or use Django’s manage.py.
For FastAPI, expose app = FastAPI(). Rimbra runs uvicorn main:app.
For Flask, expose app = Flask(__name__) and include gunicorn or flask in your dependencies.

With a start script, Rimbra runs npm start (or the package manager your lockfile uses).
Without one, it runs the file in "main", then server.js, index.js or app.js.
Commit your lockfile so installs are fast and repeatable.

Open project Settings to set your own Root directory, Install command, Build command, Start command and Port. They are used from the next deployment.