SvelteKit Proxy

A lightweight proxy utility for SvelteKit applications.
Since the built-in Vite server proxy only works in development mode,
this package provides a simple way to proxy requests in production using SvelteKit's hooks.server.ts.

How to

1. Install

   npm install sveltekit-proxy
   # or
   yarn add sveltekit-proxy
   # or
   bun add sveltekit-proxy

2. Import

   import { handleProxy } from 'sveltekit-proxy';

3. Use it

   // hooks.server.ts
   const apiPath = '/api'
   
   export const handle: Handle = async ({ event, resolve }) => {
     if (event.url.pathname.startsWith(apiPath)) {
       return handleProxy({
         target: 'https://example.com',
         rewrite: (path) => path.replace(apiPath, ''),
         origin: 'https://your-app-domain.com',
         onRequest: ({ request }) => {
           // Optionally modify the request before forwarding
           const headers = new Headers(request.headers);
           headers.set('x-proxied-by', 'sveltekit-proxy');
           return new Request(request, { headers });
         },
         onResponse: ({ response, duration }) => {
           // Optionally log response info
           console.log(`[Proxy] ${response.status} in ${duration.toFixed(2)}ms`);
         },
         onError: ({ error, request }) => {
           console.error('[Proxy Error]', error, request.url);
         },
       })({ event, resolve });
     }
   
     return resolve(event);
   };

4. Options

| Name | Description | Required | Default | |---|---|---|---| | target | Target proxy URL | Yes | | | origin | Set to avoid the abused proxy, only permitted if the origin is valid. Default undefined which will allow from all | No | undefined | | rewrite | Rewrite the path | No | undefined | | fetch | Custom fetch function | No | undefined | | onRequest | Callback to modify the outgoing Request before sending. Must return a Request. | No | undefined | | onResponse | Callback after receiving the response. Useful for logging or metrics. | No | undefined | | onError | Callback when fetch fails or throws an error. | No | undefined |

🪶 Notes

• The function returns a valid SvelteKit Handle — you can compose it inside your main handle chain.
• Request objects are immutable; to modify headers or body, return a new Request instance inside onRequest.

🧱 License

MIT © 2025 — Crafted for SvelteKit developers.