Require authentication on API routes; upgrade Next.js

.dockerignore

@@ -0,0 +1,2 @@
+.env*
+.azure

.env.example

@@ -1,3 +1,9 @@
+# How API routes authenticate callers: "easyauth" (Azure Container Apps
+# built-in authentication) or "anonymous" (no auth, local testing only).
+# When unset, `npm run dev` allows anonymous access and `npm start` rejects
+# every API request.
+# AUTH_MODE=
+
 # The Llama Cloud API key.
 # LLAMA_CLOUD_API_KEY=
 

README.md

@@ -247,6 +247,35 @@ However, you can use the [Azure pricing calculator](https://azure.com/e/bf51ef20
 
 ### Security
 
+> [!IMPORTANT]
+> This is a sample. Review it against your own security requirements before you put real data in `./data` or expose it to users.
+
+#### Authentication
+
+Every API route (`/api/chat`, `/api/chat/upload`, `/api/files/*`, `/api/sandbox`, `/api/chat/config`) checks the caller before it reads files, touches the index, or calls Azure OpenAI. The `AUTH_MODE` environment variable controls the check:
+
+| `AUTH_MODE` | Behavior                                                                                                                                                                                                                                                                                                                                                                  |
+| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| _unset_     | `npm run dev` allows anonymous access so local development keeps working. `npm start` and the container image reject every API request with `401`.                                                                                                                                                                                                                        |
+| `easyauth`  | Requires the `X-MS-CLIENT-PRINCIPAL-ID` header that [Azure Container Apps built-in authentication](https://learn.microsoft.com/azure/container-apps/authentication) sets for signed-in users. Only set this when built-in authentication is enabled and requires sign-in. Container Apps strips that header from client requests only when built-in authentication is on. |
+| `anonymous` | No authentication. Don't use this on a public endpoint. It's only for local testing or when another gateway authenticates every request.                                                                                                                                                                                                                                  |
+
+#### Turn on sign-in for your deployment
+
+A fresh `azd up` deploys an app whose API returns `401` until you turn on sign-in:
+
+1. In the Azure portal, open the `llama-index-javascript` container app in the `rg-<env-name>` resource group.
+2. Go to **Settings > Authentication > Add identity provider**, pick **Microsoft**, and let it create a new app registration. Keep **Require authentication** and **HTTP 302 Found redirect**.
+3. Tell the app to trust the signed-in user headers:
+
+   ```shell
+   az containerapp update --name llama-index-javascript --resource-group rg-<env-name> --set-env-vars AUTH_MODE=easyauth
+   ```
+
+`azd provision` and `azd up` reset the container's environment variables, so run step 3 again after either one. The authentication settings from step 2 stay in place.
+
+#### Credentials
+
 > [!NOTE]
 > When implementing this template please specify whether the template uses Managed Identity or Key Vault
 

app/api/auth.ts

@@ -0,0 +1,77 @@
+import { NextResponse } from "next/server";
+
+/**
+ * Inbound authentication gate for every API route.
+ *
+ * AUTH_MODE controls how callers are authenticated:
+ * - "easyauth": Azure Container Apps built-in authentication (EasyAuth) is
+ *   enabled in front of the app. Requests must carry the
+ *   X-MS-CLIENT-PRINCIPAL-ID header, which the platform sets for signed-in
+ *   callers and strips from any client-supplied request.
+ * - "anonymous": no authentication. Only use this for local development or
+ *   when another trusted gateway authenticates every request.
+ *
+ * When AUTH_MODE is unset, a development build (`next dev`) allows anonymous
+ * access for local development, while a production build (`next start`, the
+ * container image) fails closed and rejects every API request. Unknown values
+ * also fail closed.
+ */
+export type AuthMode = "easyauth" | "anonymous" | "unconfigured";
+
+const PRINCIPAL_ID_HEADER = "x-ms-client-principal-id";
+
+// `next build` inlines NODE_ENV, so a production build can't be switched back
+// to the anonymous development fallback by setting NODE_ENV at runtime.
+const IS_DEV_BUILD = process.env.NODE_ENV === "development";
+
+let warned = false;
+
+export function resolveAuthMode(
+  env: Record<string, string | undefined> = process.env,
+): AuthMode {
+  const mode = env.AUTH_MODE?.trim().toLowerCase();
+  if (mode === "easyauth") return "easyauth";
+  if (mode === "anonymous") return "anonymous";
+  if (!mode && IS_DEV_BUILD) return "anonymous";
+  return "unconfigured";
+}
+
+function warnOnce(message: string) {
+  if (!warned) {
+    warned = true;
+    console.warn(`[auth] ${message}`);
+  }
+}
+
+/**
+ * Returns a 401 response when the request is not authenticated, or null when
+ * the request may proceed.
+ */
+export function checkAuth(headers: Headers): NextResponse | null {
+  const mode = resolveAuthMode();
+
+  if (mode === "anonymous") {
+    if (!IS_DEV_BUILD) {
+      warnOnce(
+        "AUTH_MODE=anonymous: API routes are reachable without authentication.",
+      );
+    }
+    return null;
+  }
+
+  if (mode === "easyauth" && headers.get(PRINCIPAL_ID_HEADER)) {
+    return null;
+  }
+
+  if (mode === "unconfigured") {
+    warnOnce(
+      "Rejecting API requests because authentication is not configured. " +
+        "Enable Azure Container Apps authentication and set AUTH_MODE=easyauth.",
+    );
+  }
+
+  return NextResponse.json(
+    { error: "Unauthorized" },
+    { status: 401, headers: { "Cache-Control": "no-store" } },
+  );
+}

app/api/chat/config/llamacloud/route.ts

@@ -1,10 +1,14 @@
 import { LLamaCloudFileService } from "llamaindex";
-import { NextResponse } from "next/server";
+import { NextRequest, NextResponse } from "next/server";
+import { checkAuth } from "../../../auth";
 
 /**
  * This API is to get config from the backend envs and expose them to the frontend
  */
-export async function GET() {
+export async function GET(request: NextRequest) {
+  const denied = checkAuth(request.headers);
+  if (denied) return denied;
+
   if (!process.env.LLAMA_CLOUD_API_KEY) {
     return NextResponse.json(
       {

app/api/chat/config/route.ts

@@ -1,9 +1,13 @@
-import { NextResponse } from "next/server";
+import { NextRequest, NextResponse } from "next/server";
+import { checkAuth } from "../../auth";
 
 /**
  * This API is to get config from the backend envs and expose them to the frontend
  */
-export async function GET() {
+export async function GET(request: NextRequest) {
+  const denied = checkAuth(request.headers);
+  if (denied) return denied;
+
   const config = {
     starterQuestions: process.env.CONVERSATION_STARTERS?.trim().split("\n"),
   };

app/api/chat/route.ts

@@ -2,6 +2,7 @@ import { initObservability } from "@/app/observability";
 import { LlamaIndexAdapter, Message, StreamData } from "ai";
 import { ChatMessage, Settings } from "llamaindex";
 import { NextRequest, NextResponse } from "next/server";
+import { checkAuth } from "../auth";
 import { createChatEngine } from "./engine/chat";
 import { initSettings } from "./engine/settings";
 import {
@@ -19,6 +20,9 @@ export const runtime = "nodejs";
 export const dynamic = "force-dynamic";
 
 export async function POST(request: NextRequest) {
+  const denied = checkAuth(request.headers);
+  if (denied) return denied;
+
   // Init Vercel AI StreamData and timeout
   const vercelStreamData = new StreamData();
 

app/api/chat/upload/route.ts

@@ -1,4 +1,5 @@
 import { NextRequest, NextResponse } from "next/server";
+import { checkAuth } from "../../auth";
 import { getDataSource } from "../engine";
 import { initSettings } from "../engine/settings";
 import { uploadDocument } from "../llamaindex/documents/upload";
@@ -9,6 +10,9 @@ export const runtime = "nodejs";
 export const dynamic = "force-dynamic";
 
 export async function POST(request: NextRequest) {
+  const denied = checkAuth(request.headers);
+  if (denied) return denied;
+
   try {
     const {
       name,

app/api/files/[...slug]/route.ts

@@ -1,16 +1,20 @@
 import { readFile } from "fs/promises";
 import { NextRequest, NextResponse } from "next/server";
 import path from "path";
+import { checkAuth } from "../../auth";
 import { DATA_DIR } from "../../chat/engine/loader";
 
 /**
  * This API is to get file data from allowed folders
  * It receives path slug and response file data like serve static file
  */
 export async function GET(
-  _request: NextRequest,
+  request: NextRequest,
   { params }: { params: Promise<{ slug: string[] }> },
 ) {
+  const denied = checkAuth(request.headers);
+  if (denied) return denied;
+
   const slug = (await params).slug;
 
   if (!slug) {

app/api/sandbox/route.ts

@@ -16,6 +16,7 @@
 import { ExecutionError, Result, Sandbox } from "@e2b/code-interpreter";
 import fs from "node:fs/promises";
 import path from "node:path";
+import { checkAuth } from "../auth";
 import { saveDocument } from "../chat/llamaindex/documents/helper";
 
 type CodeArtifact = {
@@ -56,6 +57,9 @@ const SUPPORTED_TEMPLATES = [
 ];
 
 export async function POST(req: Request) {
+  const denied = checkAuth(req.headers);
+  if (denied) return denied;
+
   const { artifact }: { artifact: CodeArtifact } = await req.json();
 
   let sbx: Sandbox;

middleware.ts

@@ -0,0 +1,12 @@
+import { NextRequest, NextResponse } from "next/server";
+import { checkAuth } from "./app/api/auth";
+
+export function middleware(request: NextRequest) {
+  return checkAuth(request.headers) ?? NextResponse.next();
+}
+
+export const config = {
+  matcher: "/api/:path*",
+  // Node.js runtime so AUTH_MODE is read at runtime, not inlined at build time.
+  runtime: "nodejs",
+};

next.config.json

@@ -14,5 +14,8 @@
   },
   "transpilePackages": [
     "highlight.js"
-  ]
+  ],
+  "experimental": {
+    "middlewareClientMaxBodySize": "50mb"
+  }
 }