Configuration - CodeSandbox Documentation

There are some advanced use cases where you might need more control over a sandbox or template. That's why we support configuration files. Every template on CodeSandbox has a list of configuration files it supports. You can see the supported files under Configuration Files from the left-hand activity bar in the editor.

Configuration UI

Some configuration files can be configured using a UI. This UI will generate a configuration file based on its state.

Sandbox Configuration

A sandbox can be configured too, you can do this with sandbox.config.json. We support these options:

Option	Description	Possible Values	Default Value
`infiniteLoopProtection`	Whether we should throw an error if we detect an infinite loop	`true`/`false`	`true`
`hardReloadOnChange`	Whether we should refresh the sandbox page on every change, good for sandboxes with global state	`true`/`false`	`false`
`template`	Which sandbox template to use	see here	smart detection, w/ fallback to `create-react-app`
`view`	Which view to show first in the preview	Client: `browser`/`console`/`problems`/`tests` Container: `browser`/`console`/`problems`/`terminal`	`browser`
`container`	The container object contains the configurable port and/or startScript option, for example: `container: { port: 3212, startScript: "custom"}`
`port`	The main port which the browser window listens to	1024 - 65535	First opened port inside the container.
`startScript`	Explicitly specify the start script used in a container sandbox, overriding the default value	A String matching a script name defined under `scripts` in `package.json`	`dev` / `develop` / `serve` / `start`

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