No Start Command Could be Found

What This Error Means

Railway uses Nixpacks to analyze your application's files to generate a container image for your application.s

Seeing the No start command could be found error means that Nixpacks was unable to automatically find an appropriate start command for your application.

A start command is a command that will be executed by Railway to run your application.

Why This Error Can Occur

By default, Railway uses Nixpacks to build and run your application. Nixpacks will try its best to find an appropriate start command for your application.

Some limited examples of start commands that Nixpacks will try are -

For Node based apps it will try to use npm start, yarn start, pnpm start, or bun start if a start script is present in your package.json file.

For Python apps it will try to use python main.py if a main.py file is present, or python manage.py migrate && gunicorn {app_name}.wsgi if a Django application is detected.

For Ruby apps it will try to use bundle exec rails server -b 0.0.0.0 if a Rails application is detected.

Failing the automatic detection, Nixpacks will return the No start command could be found error.

Possible Solutions

Since Nixpacks was unable to find a start command, you will need to specify a start command yourself.

You can do this in the service settings under the Start Command field.

Some common start commands for various frameworks and languages are -

Node.js

node main.js

Where main.js is the entry point for your application, could be index.js, server.js, app.js, etc.

Next.js

npx next start --port $PORT

Note: The --port flag is needed to ensure that Next.js listens on the correct port.

Nuxt.js

node .output/server/index.mjs

This will run Nuxt.js in production mode using its built-in Nitro server.

FastAPI

uvicorn main:app --host 0.0.0.0 --port $PORT

Where main is the name of the file that contains the app variable from FastAPI.

Note: The --host and --port flags are needed to ensure that FastAPI listens on the correct host and port.

Flask

gunicorn main:app

Where main is the name of the file that contains the app variable from Flask.

Django

gunicorn myproject.wsgi

Where myproject is the name of the folder that contains your wsgi.py file.

Ruby on Rails

bundle exec rails server -b 0.0.0.0 -p $PORT

Note: The -b and -p flags are needed to ensure that Rails listens on the correct host and port.

Vite

serve --single --listen $PORT dist

Note: The serve command is needed to serve the static site files and can be installed by running npm install serve locally.

Create React App

serve --single --listen $PORT build

Note: The serve command is needed to serve the static site files and can be installed by running npm install serve locally.