feat: enhance authentication and cookie handling

- Added rewrites in next.config.ts to proxy API requests to the backend.
- Introduced authCookies utility for forwarding cookies from Next.js to the backend for authentication.
- Implemented nextCookiesRequest plugin to manage cookie headers during requests.
- Updated auth-client.ts to include nextCookiesRequest for improved session management.

Author: 0xdevcollins

lib/auth-client.ts

@@ -6,6 +6,7 @@ import {
   oneTapClient,
   organizationClient,
 } from 'better-auth/client/plugins';
+import { nextCookiesRequest } from './next-cookies-request';
 
 const getAuthBaseURL = () => {
   const apiUrl =
@@ -17,6 +18,7 @@ const getAuthBaseURL = () => {
 export const authClient = createAuthClient({
   baseURL: getAuthBaseURL(),
   plugins: [
+    nextCookiesRequest,
     inferAdditionalFields({
       user: {
         profile: { type: 'json', required: false },

lib/auth-cookies.ts

@@ -0,0 +1,44 @@
+/**
+ * Cookie forwarding utilities for Better Auth with separate backend setup
+ *
+ * This module provides helpers to forward cookies from Next.js server-side requests
+ * to your backend API for proper authentication handling.
+ *
+ * Usage in server components/actions:
+ * ```typescript
+ * const { data: session } = await authClient.getSession(await authCookies());
+ * ```
+ *
+ * Backend Configuration Requirements:
+ * Your backend must include your frontend in `trustedOrigins`:
+ * ```typescript
+ * export const auth = betterAuth({
+ *   trustedOrigins: ['http://localhost:3000'] // Your frontend URL
+ * });
+ * ```
+ *
+ * OAuth Configuration:
+ * Configure redirectURI to point to your backend:
+ * ```typescript
+ * socialProviders: {
+ *   google: {
+ *     redirectURI: "http://localhost:3001/api/auth/callback/google" // Backend URL
+ *   }
+ * }
+ * ```
+ *
+ * When calling authClient.signIn.social, set callbackURL to your frontend URL.
+ */
+
+import { cookies } from 'next/headers';
+
+export async function authCookies() {
+  const cookie = await cookies();
+  return {
+    fetchOptions: {
+      headers: {
+        Cookie: cookie.toString(),
+      },
+    },
+  };
+}

lib/next-cookies-request.ts

@@ -0,0 +1,18 @@
+export const nextCookiesRequest = {
+  id: 'next-cookies-request',
+  fetchPlugins: [
+    {
+      id: 'next-cookies-request-plugin',
+      name: 'next-cookies-request-plugin',
+      hooks: {
+        async onRequest(ctx: any) {
+          if (typeof window === 'undefined') {
+            const { cookies } = await import('next/headers');
+            const headers = await cookies();
+            ctx.headers.set('cookie', headers.toString());
+          }
+        },
+      },
+    },
+  ],
+};

next.config.ts

@@ -2,6 +2,14 @@ import type { NextConfig } from 'next';
 
 const nextConfig: NextConfig = {
   outputFileTracingRoot: __dirname,
+  async rewrites() {
+    return [
+      {
+        source: '/api/:path*',
+        destination: process.env.NEXT_PUBLIC_API_URL + '/api/:path*', // Proxy to Backend
+      },
+    ];
+  },
   images: {
     remotePatterns: [
       {