Proxy #

Prestige uses a small proxy server to execute the actual HTTP requests. The reason for this is to avoid CORS restrictions by the browser. Briefly, what that means is that browsers don’t let a web app running on abc.com to execute HTTP requests to xyz.com, as a security measure. But in Prestige, even though it’s opened from prestige.dev, we’d want to execute requests on other domains. Without that capability, Prestige would be a lot less useful, honestly.

So, to resolve this, Prestige has a small proxy server running on the prestige.dev server which executes the requests on your behalf.

Local Endpoints #

A consequence of using a proxy hosted elsewhere is that if you are hitting requests on localhost, they won’t work. The reason is resources on localhost are obviously hosted on your local machine, which are not accessible to the outside internet (at least not as localhost). So, the proxy server up on prestige.dev has no idea what to do with it.

However, you might’ve noticed that requests to localhost do partially work in Prestige. It’s not magic though. Prestige intelligently doesn’t use a proxy when making requests to localhost.

Customizing the Proxy #

The function getProxyUrl from the current execution context should return the URL which will be used as the proxy. So, to disable the use of proxy for any and all requests, we could just add a Javascript block at the top of the sheet with the following:

### javascript
this.getProxyUrl = () => null;

The request being executed will be passed as an argument to the getProxyUrl function, so we could decide to use a proxy for some URLs and not for others.

### javascript
this.getProxyUrl = (request) => {
	if (request.url.includes("httpbun.com")) {
		// Don't use a proxy for these requests.
		return null;
	} else {
		// Use the default behavior otherwise.
		return "@super";
	}
}

Notice here that we are returning the string "@super" which tells Proxy to use the default behavior, essentially like calling the original getProxyUrl method. Here’s how the return value of this function is interpreted by Prestige:

Returns	Implication
`null`	Don’t use a proxy. Execute the request directly. This will fail if the server denies CORS.
`"@super"`	Behave as if `this.getProxyUrl` hasn’t been customized at all. That is, don’t use proxy for `localhost` URLs, use proxy otherwise.
`"@default"`	Use the default Prestige proxy for executing this request.
Any other string	Treated as the proxy URL to use.

Conclusion #

The proxy is necessary piece of the puzzle to be able to run an HTTP request to any endpoint. For the most part though, you shouldn’t have to be concerned with it. But I’ll point out that it is important to understand that it exists, and it does what it does. Check our the API Reference to learn more about how to customize the proxy that Prestige uses (or doesn’t use).