feat(auth): extend API key authentication to tRPC endpoints (#4732)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

apps/nextjs/src/app/api/[...trpc]/route.ts

@@ -3,21 +3,24 @@ import { userAgent } from "next/server";
 import { createOpenApiFetchHandler } from "trpc-to-openapi";
 
 import { appRouter, createTRPCContext } from "@homarr/api";
-import type { Session } from "@homarr/auth";
-import { hashPasswordAsync } from "@homarr/auth";
-import { createSessionAsync } from "@homarr/auth/server";
+import { API_KEY_HEADER_NAME, getSessionFromApiKeyAsync } from "@homarr/auth/api-key";
+import { ipAddressFromHeaders } from "@homarr/common/server";
 import { createLogger } from "@homarr/core/infrastructure/logs";
 import { ErrorWithMetadata } from "@homarr/core/infrastructure/logs/error";
-import { db, eq } from "@homarr/db";
-import { apiKeys } from "@homarr/db/schema";
+import { db } from "@homarr/db";
 
 const logger = createLogger({ module: "trpcOpenApiRoute" });
 
 const handlerAsync = async (req: NextRequest) => {
-  const apiKeyHeaderValue = req.headers.get("ApiKey");
-  const ipAddress = req.headers.get("x-forwarded-for");
+  const apiKeyHeaderValue = req.headers.get(API_KEY_HEADER_NAME);
+  const ipAddress = ipAddressFromHeaders(req.headers);
   const { ua } = userAgent(req);
-  const session: Session | null = await getSessionOrDefaultFromHeadersAsync(apiKeyHeaderValue, ipAddress, ua);
+
+  logger.info(
+    `Creating OpenAPI fetch handler for user ${apiKeyHeaderValue ? "with an api key" : "without an api key"}`,
+  );
+
+  const session = await getSessionFromApiKeyAsync(db, apiKeyHeaderValue, ipAddress, ua);
 
   // Fallback to JSON if no content type is set
   if (!req.headers.has("Content-Type")) {
@@ -35,67 +38,6 @@ const handlerAsync = async (req: NextRequest) => {
   });
 };
 
-const getSessionOrDefaultFromHeadersAsync = async (
-  apiKeyHeaderValue: string | null,
-  ipAdress: string | null,
-  userAgent: string,
-): Promise<Session | null> => {
-  logger.info(
-    `Creating OpenAPI fetch handler for user ${apiKeyHeaderValue ? "with an api key" : "without an api key"}`,
-  );
-
-  if (apiKeyHeaderValue === null) {
-    return null;
-  }
-
-  const [apiKeyId, apiKey] = apiKeyHeaderValue.split(".");
-
-  if (!apiKeyId || !apiKey) {
-    logger.warn("An attempt to authenticate over API has failed due to invalid API key format", {
-      ipAdress,
-      userAgent,
-    });
-    return null;
-  }
-
-  const apiKeyFromDb = await db.query.apiKeys.findFirst({
-    where: eq(apiKeys.id, apiKeyId),
-    columns: {
-      id: true,
-      apiKey: true,
-      salt: true,
-    },
-    with: {
-      user: {
-        columns: {
-          id: true,
-          name: true,
-          email: true,
-          emailVerified: true,
-        },
-      },
-    },
-  });
-
-  if (!apiKeyFromDb) {
-    logger.warn("An attempt to authenticate over API has failed", { ipAdress, userAgent });
-    return null;
-  }
-
-  const hashedApiKey = await hashPasswordAsync(apiKey, apiKeyFromDb.salt);
-
-  if (apiKeyFromDb.apiKey !== hashedApiKey) {
-    logger.warn("An attempt to authenticate over API has failed", { ipAdress, userAgent });
-    return null;
-  }
-
-  logger.info("Read session from API request and found user", {
-    name: apiKeyFromDb.user.name,
-    id: apiKeyFromDb.user.id,
-  });
-  return await createSessionAsync(db, apiKeyFromDb.user);
-};
-
 export {
   handlerAsync as DELETE,
   handlerAsync as GET,

apps/nextjs/src/app/api/trpc/[trpc]/route.ts

@@ -1,10 +1,14 @@
+import { userAgent } from "next/server";
 import { fetchRequestHandler } from "@trpc/server/adapters/fetch";
 
 import { appRouter, createTRPCContext } from "@homarr/api";
 import { trpcPath } from "@homarr/api/shared";
+import { API_KEY_HEADER_NAME, getSessionFromApiKeyAsync } from "@homarr/auth/api-key";
 import { auth } from "@homarr/auth/next";
+import { ipAddressFromHeaders } from "@homarr/common/server";
 import { createLogger } from "@homarr/core/infrastructure/logs";
 import { ErrorWithMetadata } from "@homarr/core/infrastructure/logs/error";
+import { db } from "@homarr/db";
 
 const logger = createLogger({ module: "trpcRoute" });
 
@@ -28,11 +32,20 @@ export function OPTIONS() {
 }
 
 const handler = auth(async (req) => {
+  // Try API key auth first, fall back to session cookie
+  const apiKeyHeader = req.headers.get(API_KEY_HEADER_NAME);
+  const ipAddress = ipAddressFromHeaders(req.headers);
+
+  const { ua } = userAgent(req);
+
+  const apiKeySession = await getSessionFromApiKeyAsync(db, apiKeyHeader, ipAddress, ua);
+  const session = apiKeySession ?? req.auth;
+
   const response = await fetchRequestHandler({
     endpoint: trpcPath,
     router: appRouter,
     req,
-    createContext: () => createTRPCContext({ session: req.auth, headers: req.headers }),
+    createContext: () => createTRPCContext({ session, headers: req.headers }),
     onError({ error, path, type }) {
       logger.error(new ErrorWithMetadata("tRPC Error occured", { path, type }, { cause: error }));
     },

packages/api/src/open-api.ts

@@ -1,5 +1,7 @@
 import { generateOpenApiDocument } from "trpc-to-openapi";
 
+import { API_KEY_HEADER_NAME } from "@homarr/auth/api-key";
+
 import { appRouter } from "./root";
 
 export const openApiDocument = (base: string) =>
@@ -11,7 +13,7 @@ export const openApiDocument = (base: string) =>
     securitySchemes: {
       apikey: {
         type: "apiKey",
-        name: "ApiKey",
+        name: API_KEY_HEADER_NAME,
         description: "API key which can be obtained in the Homarr administration dashboard",
         in: "header",
       },

packages/auth/api-key/constants.ts

@@ -0,0 +1 @@
+export const API_KEY_HEADER_NAME = "ApiKey";

packages/auth/api-key/get-api-key-session.ts

@@ -0,0 +1,76 @@
+import type { Session } from "next-auth";
+
+import { createLogger } from "@homarr/core/infrastructure/logs";
+import type { Database } from "@homarr/db";
+import { eq } from "@homarr/db";
+import { apiKeys } from "@homarr/db/schema";
+
+import { hashPasswordAsync } from "../security";
+import { createSessionAsync } from "../server";
+
+const logger = createLogger({ module: "apiKeyAuth" });
+
+/**
+ * Validate an API key from the request header and return a session if valid.
+ *
+ * @param db - The database instance
+ * @param apiKeyHeaderValue - The value of the ApiKey header (format: "id.token")
+ * @param ipAddress - The IP address of the request (for logging)
+ * @param userAgent - The user agent of the request (for logging)
+ * @returns A session if the API key is valid, null otherwise
+ */
+export const getSessionFromApiKeyAsync = async (
+  db: Database,
+  apiKeyHeaderValue: string | null,
+  ipAddress: string | null,
+  userAgent: string,
+): Promise<Session | null> => {
+  if (apiKeyHeaderValue === null) {
+    return null;
+  }
+
+  const [apiKeyId, apiKey] = apiKeyHeaderValue.split(".");
+
+  if (!apiKeyId || !apiKey) {
+    logger.warn("Failed to authenticate with api-key", { ipAddress, userAgent, reason: "API_KEY_INVALID_FORMAT" });
+    return null;
+  }
+
+  const apiKeyFromDb = await db.query.apiKeys.findFirst({
+    where: eq(apiKeys.id, apiKeyId),
+    columns: {
+      id: true,
+      apiKey: true,
+      salt: true,
+    },
+    with: {
+      user: {
+        columns: {
+          id: true,
+          name: true,
+          email: true,
+          emailVerified: true,
+        },
+      },
+    },
+  });
+
+  if (!apiKeyFromDb) {
+    logger.warn("Failed to authenticate with api-key", { ipAddress, userAgent, reason: "API_KEY_NOT_FOUND" });
+    return null;
+  }
+
+  const hashedApiKey = await hashPasswordAsync(apiKey, apiKeyFromDb.salt);
+
+  if (apiKeyFromDb.apiKey !== hashedApiKey) {
+    logger.warn("Failed to authenticate with api-key", { ipAddress, userAgent, reason: "API_KEY_MISMATCH" });
+    return null;
+  }
+
+  logger.info("Successfully authenticated with api-key", {
+    name: apiKeyFromDb.user.name,
+    id: apiKeyFromDb.user.id,
+  });
+
+  return await createSessionAsync(db, apiKeyFromDb.user);
+};

packages/auth/api-key/index.ts

@@ -0,0 +1,2 @@
+export { getSessionFromApiKeyAsync } from "./get-api-key-session";
+export { API_KEY_HEADER_NAME } from "./constants";

packages/auth/api-key/test/get-api-key-session.spec.ts

@@ -0,0 +1,133 @@
+/* eslint-disable @typescript-eslint/no-non-null-assertion */
+import { describe, expect, test, vi } from "vitest";
+
+import { createId } from "@homarr/common";
+import { apiKeys, users } from "@homarr/db/schema";
+import { createDb } from "@homarr/db/test";
+
+import { createSaltAsync, hashPasswordAsync } from "../../security";
+import { getSessionFromApiKeyAsync } from "../get-api-key-session";
+
+// Mock the logger to avoid console output during tests
+vi.mock("@homarr/core/infrastructure/logs", () => ({
+  createLogger: () => ({
+    warn: vi.fn(),
+    info: vi.fn(),
+  }),
+}));
+
+const defaultUserId = createId();
+const defaultUsername = "testuser";
+const defaultApiKeyId = createId();
+const defaultIpAddress = "127.0.0.1";
+const defaultUserAgent = "test-agent";
+const defaultLogParams = [defaultIpAddress, defaultUserAgent] as const;
+
+describe("getSessionFromApiKeyAsync", () => {
+  test("should return null when api key header is null", async () => {
+    // Arrange
+    const { db } = await setupAsync();
+    const apiKey = null;
+
+    // Act
+    const result = await getSessionFromApiKeyAsync(db, apiKey, ...defaultLogParams);
+
+    // Assert
+    expect(result).toBeNull();
+  });
+
+  test.each([
+    ["invalidformat", "no dot"],
+    ["keyid.", "missing token"],
+    [".token", "missing id"],
+  ])("should return null when api key format is invalid key=%s reason=%s", async (apiKey) => {
+    // Arrange
+    const { db } = await setupAsync();
+
+    // Act
+    const result = await getSessionFromApiKeyAsync(db, apiKey, ...defaultLogParams);
+
+    // Assert
+    expect(result).toBeNull();
+  });
+
+  test("should return null when api key is not found in database", async () => {
+    // Arrange
+    const { db } = await setupAsync();
+
+    // Act
+    const result = await getSessionFromApiKeyAsync(db, "nonexistent.token", ...defaultLogParams);
+
+    // Assert
+    expect(result).toBeNull();
+  });
+
+  test("should return null when api key token does not match", async () => {
+    // Arrange
+    const { db } = await setupAsync({ token: "correcttoken" });
+
+    // Act
+    const result = await getSessionFromApiKeyAsync(db, `${defaultApiKeyId}.wrongtoken`, ...defaultLogParams);
+
+    // Assert
+    expect(result).toBeNull();
+  });
+
+  test("should return session when api key is valid", async () => {
+    // Arrange
+    const token = "validtesttoken123";
+    const { db } = await setupAsync({ token });
+
+    // Act
+    const result = await getSessionFromApiKeyAsync(db, `${defaultApiKeyId}.${token}`, ...defaultLogParams);
+
+    // Assert
+    expect(result).not.toBeNull();
+    expect(result!.user.id).toEqual(defaultUserId);
+    expect(result!.user.name).toEqual(defaultUsername);
+  });
+
+  test("should work with null ip address", async () => {
+    // Arrange
+    const token = "validtesttoken456";
+    const { db } = await setupAsync({ token });
+
+    // Act
+    const result = await getSessionFromApiKeyAsync(db, `${defaultApiKeyId}.${token}`, null, defaultUserAgent);
+
+    // Assert
+    expect(result).not.toBeNull();
+    expect(result!.user.id).toEqual(defaultUserId);
+  });
+});
+
+interface SetupOptions {
+  /**
+   * If provided, inserts an API key into the database for testing.
+   */
+  token?: string;
+}
+
+const setupAsync = async (options?: SetupOptions) => {
+  const db = createDb();
+
+  await db.insert(users).values({
+    id: defaultUserId,
+    name: defaultUsername,
+    email: "test@example.com",
+  });
+
+  if (options?.token) {
+    const salt = await createSaltAsync();
+    await db.insert(apiKeys).values({
+      id: defaultApiKeyId,
+      apiKey: await hashPasswordAsync(options.token, salt),
+      salt,
+      userId: defaultUserId,
+    });
+  }
+
+  return {
+    db,
+  };
+};

packages/auth/package.json

@@ -8,6 +8,7 @@
     ".": "./index.ts",
     "./next": "./next.ts",
     "./security": "./security.ts",
+    "./api-key": "./api-key/index.ts",
     "./client": "./client.ts",
     "./server": "./server.ts",
     "./shared": "./shared.ts",

packages/common/src/request.ts

@@ -9,3 +9,7 @@ export const userAgent = (headers: Headers) => {
 };
 
 export type DeviceType = "console" | "mobile" | "tablet" | "smarttv" | "wearable" | "embedded" | undefined;
+
+export const ipAddressFromHeaders = (headers: Headers): string | null => {
+  return headers.get("x-forwarded-for");
+};

packages/common/src/server.ts

@@ -1,4 +1,4 @@
 export * from "./security";
 export * from "./encryption";
-export * from "./user-agent";
+export * from "./request";
 export * from "./errors";