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.