alexdln · alexdln · May 16, 2026 · Feb 10, 2026 · Feb 10, 2026 · Feb 10, 2026
diff --git a/README.md b/README.md
@@ -71,6 +71,7 @@ This is not Koa and not Express, this is a package for next.js, in its unique st
 - [Base example](https://github.com/alexdln/nimpl-proxy-chain/tree/main/examples/base).
 - [next-auth + next-intl example](https://github.com/alexdln/nimpl-proxy-chain/tree/main/examples/auth-intl).
 - [next-auth5 + next-intl example](https://github.com/alexdln/nimpl-proxy-chain/tree/main/examples/auth5-intl).
+- [Custom auth](https://github.com/alexdln/nimpl-proxy-chain/tree/main/examples/basic-auth).
 
 ## Development
 

diff --git a/examples/basic-auth/.env b/examples/basic-auth/.env
@@ -0,0 +1 @@
+BASIC_AUTH="login:password"
diff --git a/examples/basic-auth/.gitignore b/examples/basic-auth/.gitignore
@@ -0,0 +1,37 @@
+# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+
+# dependencies
+/node_modules
+/.pnp
+.pnp.js
+.yarn/install-state.gz
+pnpm-lock.yaml
+
+# testing
+/coverage
+
+# next.js
+/.next/
+/out/
+
+# production
+/build
+
+# misc
+.DS_Store
+*.pem
+
+# debug
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# local env files
+.env*.local
+
+# vercel
+.vercel
+
+# typescript
+*.tsbuildinfo
+next-env.d.ts
diff --git a/examples/basic-auth/README.md b/examples/basic-auth/README.md
@@ -0,0 +1,36 @@
+This is a [Next.js](https://nextjs.org/) project bootstrapped with [`create-next-app`](https://github.com/vercel/next.js/tree/canary/packages/create-next-app).
+
+## Getting Started
+
+First, run the development server:
+
+```bash
+npm run dev
+# or
+yarn dev
+# or
+pnpm dev
+# or
+bun dev
+```
+
+Open [http://localhost:3000](http://localhost:3000) with your browser to see the result.
+
+You can start editing the page by modifying `app/page.tsx`. The page auto-updates as you edit the file.
+
+This project uses [`next/font`](https://nextjs.org/docs/basic-features/font-optimization) to automatically optimize and load Inter, a custom Google Font.
+
+## Learn More
+
+To learn more about Next.js, take a look at the following resources:
+
+- [Next.js Documentation](https://nextjs.org/docs) - learn about Next.js features and API.
+- [Learn Next.js](https://nextjs.org/learn) - an interactive Next.js tutorial.
+
+You can check out [the Next.js GitHub repository](https://github.com/vercel/next.js/) - your feedback and contributions are welcome!
+
+## Deploy on Vercel
+
+The easiest way to deploy your Next.js app is to use the [Vercel Platform](https://vercel.com/new?utm_medium=default-template&filter=next.js&utm_source=create-next-app&utm_campaign=create-next-app-readme) from the creators of Next.js.
+
+Check out our [Next.js deployment documentation](https://nextjs.org/docs/deployment) for more details.
diff --git a/examples/basic-auth/next.config.mjs b/examples/basic-auth/next.config.mjs
@@ -0,0 +1,4 @@
+/** @type {import('next').NextConfig} */
+const nextConfig = {};
+
+export default nextConfig;
diff --git a/examples/basic-auth/package.json b/examples/basic-auth/package.json
@@ -0,0 +1,22 @@
+{
+  "name": "examples-basic-auth",
+  "version": "1.1.0",
+  "private": true,
+  "scripts": {
+    "dev": "next dev",
+    "build": "NODE_ENV=production next build",
+    "start": "next start"
+  },
+  "dependencies": {
+    "@nimpl/proxy-chain": "workspace:*",
+    "next": "16.1.1",
+    "react": "19.2.3",
+    "react-dom": "19.2.3"
+  },
+  "devDependencies": {
+    "@types/node": "25.0.3",
+    "@types/react": "19.2.7",
+    "@types/react-dom": "19.2.3",
+    "typescript": "5.9.3"
+  }
+}
diff --git a/examples/basic-auth/public/next.svg b/examples/basic-auth/public/next.svg
diff --git a/examples/basic-auth/public/vercel.svg b/examples/basic-auth/public/vercel.svg
diff --git a/examples/basic-auth/src/app/favicon.ico b/examples/basic-auth/src/app/favicon.ico
diff --git a/examples/basic-auth/src/app/globals.css b/examples/basic-auth/src/app/globals.css
@@ -0,0 +1,16 @@
+* {
+  box-sizing: border-box;
+  padding: 0;
+  margin: 0;
+}
+
+html,
+body {
+  max-width: 100vw;
+  overflow-x: hidden;
+}
+
+a {
+  color: inherit;
+  text-decoration: none;
+}
diff --git a/examples/basic-auth/src/app/layout.tsx b/examples/basic-auth/src/app/layout.tsx
@@ -0,0 +1,20 @@
+import { type Metadata } from "next/types";
+
+import "./globals.css";
+
+export const metadata: Metadata = {
+    title: "Create Next App",
+    description: "Generated by create next app",
+};
+
+export default function RootLayout({
+    children,
+}: Readonly<{
+    children: React.ReactNode;
+}>) {
+    return (
+        <html lang="en">
+            <body>{children}</body>
+        </html>
+    );
+}
diff --git a/examples/basic-auth/src/app/page.tsx b/examples/basic-auth/src/app/page.tsx
@@ -0,0 +1,7 @@
+export default function Home() {
+    return (
+        <div>
+            <p>Home page</p>
+        </div>
+    );
+}
diff --git a/examples/basic-auth/src/basicAuthMiddleware.ts b/examples/basic-auth/src/basicAuthMiddleware.ts
@@ -0,0 +1,58 @@
+import { NextRequest, NextResponse } from "next/server";
+
+const BASIC_AUTH_COOKIE_NAME = "__basic_auth";
+const COOKIE_MAX_AGE = 60 * 60 * 24 * 14; // 14 days
+
+function createAuthHash(username: string, password: string): string {
+    return Buffer.from(`${username}:${password}`).toString("base64");
+}
+
+export const basicAuthMiddleware = async (request: NextRequest) => {
+    if (!process.env.BASIC_AUTH) {
+        return;
+    }
+
+    const basicAuthParts = process.env.BASIC_AUTH.split(":");
+    if (basicAuthParts.length !== 2 || !basicAuthParts[0] || !basicAuthParts[1]) {
+        console.error('Server misconfiguration: BASIC_AUTH must be in "username:password" format');
+        return new Response("Server misconfiguration", {
+            status: 500,
+        });
+    }
+    const [username, password] = basicAuthParts;
+    const expectedAuthHash = createAuthHash(username, password);
+
+    // Fast path: check cookie first (covers all subsequent requests including RSC/prefetch)
+    const authCookie = request.cookies.get(BASIC_AUTH_COOKIE_NAME);
+    if (authCookie?.value === expectedAuthHash) {
+        return;
+    }
+
+    const authHeader = request.headers.get("authorization");
+    if (authHeader) {
+        const base64Credentials = authHeader.split(" ")[1];
+        if (base64Credentials) {
+            const credentials = Buffer.from(base64Credentials, "base64").toString("ascii");
+            const [inputUsername, inputPassword] = credentials.split(":");
+
+            if (inputUsername === username && inputPassword === password) {
+                // Set the auth cookie for subsequent requests and proceed to the next proxy handler
+                const nextResponse = NextResponse.next();
+                nextResponse.cookies.set(BASIC_AUTH_COOKIE_NAME, expectedAuthHash, {
+                    httpOnly: true,
+                    secure: process.env.NODE_ENV === "production",
+                    sameSite: "lax",
+                    maxAge: COOKIE_MAX_AGE,
+                    path: "/",
+                });
+                return nextResponse;
+            }
+        }
+    }
+    return new Response("Authentication required", {
+        status: 401,
+        headers: {
+            "WWW-Authenticate": 'Basic realm="Auth"',
+        },
+    });
+};
diff --git a/examples/basic-auth/src/proxy.ts b/examples/basic-auth/src/proxy.ts
@@ -0,0 +1,23 @@
+import { chain } from "@nimpl/proxy-chain";
+import { basicAuthMiddleware } from "./basicAuthMiddleware";
+import { NextResponse } from "next/server";
+
+export default chain([
+    basicAuthMiddleware,
+    async (request) => {
+        const next = NextResponse.next({
+            headers: new Headers({ "x-client-header-set-by-middleware": "true" }),
+            request: { headers: new Headers({ "x-request-pathname": request.nextUrl.pathname }) },
+        });
+        next.cookies.set("test", "cookie", { maxAge: 1000 * 60 * 60 * 24 * 30 });
+
+        return next;
+    },
+    (req) => {
+        console.log("Request summary", req.summary);
+    },
+]);
+
+export const config = {
+    matcher: ["/((?!api|_next/static|_next/image|favicon.ico|.well-known).*)"],
+};
diff --git a/examples/basic-auth/tsconfig.json b/examples/basic-auth/tsconfig.json
@@ -0,0 +1,41 @@
+{
+    "compilerOptions": {
+        "lib": [
+            "dom",
+            "dom.iterable",
+            "esnext"
+        ],
+        "allowJs": true,
+        "skipLibCheck": true,
+        "strict": true,
+        "noEmit": true,
+        "esModuleInterop": true,
+        "module": "esnext",
+        "moduleResolution": "bundler",
+        "resolveJsonModule": true,
+        "isolatedModules": true,
+        "jsx": "react-jsx",
+        "incremental": true,
+        "plugins": [
+            {
+                "name": "next"
+            }
+        ],
+        "paths": {
+            "@/*": [
+                "./src/*"
+            ]
+        },
+        "target": "ES2017"
+    },
+    "include": [
+        "next-env.d.ts",
+        "**/*.ts",
+        "**/*.tsx",
+        ".next/types/**/*.ts",
+        ".next/dev/types/**/*.ts"
+    ],
+    "exclude": [
+        "node_modules"
+    ]
+}
diff --git a/package.json b/package.json
@@ -9,7 +9,9 @@
     "prepare": "husky"
   },
   "lint-staged": {
-    "*.{ts,tsx,js,jsx}": ["eslint"]
+    "*.{ts,tsx,js,jsx}": [
+      "eslint"
+    ]
   },
   "repository": {
     "type": "git",
@@ -31,8 +33,9 @@
   "resolutions": {
     "examples-auth-intl>@nimpl/proxy-chain": "workspace:*",
     "examples-auth5-intl>@nimpl/proxy-chain": "workspace:*",
-    "examples-base>@nimpl/proxy-chain": "workspace:*"
+    "examples-base>@nimpl/proxy-chain": "workspace:*",
+    "examples-basic-auth>@nimpl/proxy-chain": "workspace:*"
   },
   "license": "MIT",
   "packageManager": "pnpm@9.7.0+sha512.dc09430156b427f5ecfc79888899e1c39d2d690f004be70e05230b72cb173d96839587545d09429b55ac3c429c801b4dc3c0e002f653830a420fa2dd4e3cf9cf"
-}
+}
diff --git a/package/package.json b/package/package.json
@@ -2,12 +2,20 @@
   "name": "@nimpl/proxy-chain",
   "version": "1.0.0",
   "description": "Create a chain of native Next.js proxies seamlessly, without changing any existing proxy code",
+  "type": "module",
   "main": "./dist/chain.js",
+  "types": "./dist/chain.d.ts",
+  "exports": {
+    ".": {
+      "types": "./dist/chain.d.ts",
+      "import": "./dist/chain.js"
+    }
+  },
   "files": [
     "dist"
   ],
   "scripts": {
-    "build": "tsc"
+    "build": "tsup"
   },
   "keywords": [
     "next",
@@ -33,6 +41,7 @@
   "license": "MIT",
   "devDependencies": {
     "next": "16.1.1",
+    "tsup": "8.5.1",
     "typescript": "5.9.3"
   },
   "peerDependencies": {

diff --git a/package/src/chain.ts b/package/src/chain.ts
@@ -23,6 +23,7 @@ export const chain =
             event,
             middlewares,
             logger,
+            config?.breakOnTypes,
         );
         const next = formatResponse(summary);
-Original file line number
+Diff line change
@@ Expand Up / @@ -23,6 +23,7 @@ export const chain = @@
                 event,
                 middlewares,
                 logger,
+                config?.breakOnTypes,
             );
             const next = formatResponse(summary);
@@ Expand Down @@