diff --git a/packages/api/src/server.ts b/packages/api/src/server.ts
index 9d427c47..05c90d3e 100644
--- a/packages/api/src/server.ts
+++ b/packages/api/src/server.ts
@@ -12,7 +12,8 @@ export const DEFAULT_PORT = 80;
 export const startServer = (config: Config, port: number) => {
   const app = express();
 
-  app.use(express.json());
+  // The default limit is 100kb, which is not enough for the signed API because some payloads can be quite large.
+  app.use(express.json({ limit: '10mb' }));
 
   app.post('/', async (req, res) => {
     logger.info('Received request "POST /".', req.body);
@@ -46,6 +47,17 @@ export const startServer = (config: Config, port: number) => {
     });
   }
 
+  // Inline error handling middleware
+  app.use((err: any, _req: express.Request, res: express.Response, _next: express.NextFunction) => {
+    logger.error('An unexpected error occurred.', { err });
+
+    res.status(err.status || 500).json({
+      error: {
+        message: err.message || 'An unexpected error occurred.',
+      },
+    });
+  });
+
   app.listen(port, () => {
     logger.info(`Server listening at http://localhost:${port}.`);
   });
diff --git a/packages/e2e/src/user.test.ts b/packages/e2e/src/user.test.ts
index 633a2c96..21426905 100644
--- a/packages/e2e/src/user.test.ts
+++ b/packages/e2e/src/user.test.ts
@@ -1,3 +1,4 @@
+import { go } from '@api3/promise-utils';
 import axios from 'axios';
 
 import { airnode, formatData } from './utils';
@@ -27,3 +28,26 @@ test('respects the delay', async () => {
   expect(realCount).toBeGreaterThan(0);
   expect(delayedCount).toBeGreaterThan(0);
 }, 20_000);
+
+test('ensures Signed API handles requests with huge payloads', async () => {
+  const signedData = {
+    signature:
+      '0x1ea0a64100431adf033ec730547cd3ffd253dd5991336b3d9b9e8dcfe68d82a61bcd9b8b677557a90a025c19ebde1d98608e2fa3462457bb6fe62675518f7f9c1c',
+    timestamp: '1701419743',
+    templateId: '0x031487ca600cd3a26a39206b5b4373f9231f75e4bd23edeb3d5bdc513c147e2a',
+    encodedValue: '0x000000000000000000000000000000000000000000000003d026ef5a02753000',
+    airnode: '0x198539e151Fc2CF7642BFfe95B2b7a3Dc08bE0b7',
+  };
+
+  const goPostData = await go(async () =>
+    axios.post(`http://localhost:8090`, Array.from({ length: 100_000 }).fill(signedData))
+  );
+
+  expect(goPostData.success).toBe(false);
+  const error = goPostData.error as any;
+  expect(error.message).toBe('Request failed with status code 413');
+  expect(error.response.status).toBe(413);
+  expect(error.response.data).toStrictEqual({
+    error: { message: 'request entity too large' },
+  });
+});