From 839132dc5f2062dc3498b0af8a1aac10b28e26ae Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Sun, 22 Mar 2026 09:30:39 +0000
Subject: [PATCH 1/2] fix(api): Increase express.json payload limit to 10mb and
 handle entity.too.large

Increased the default payload limit of `express.json()` from 100kb to 10mb to
accommodate large LLM prompts. Also added explicit error handling for
`entity.too.large` errors, returning a standard 413 Payload Too Large
JSON response instead of falling through to a generic 500 stack trace.
Added a test to verify this behavior.

Co-authored-by: shenald-dev <245350826+shenald-dev@users.noreply.github.com>
---
 .jules/bolt.md    |  9 ++++++++-
 src/index.js      |  5 ++++-
 tests/api.test.js | 14 ++++++++++++++
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/.jules/bolt.md b/.jules/bolt.md
index 1b51e80..bf0ca61 100644
--- a/.jules/bolt.md
+++ b/.jules/bolt.md
@@ -4,4 +4,11 @@ Learning:
 Swallowing `uncaughtException` and `unhandledRejection` leaves the Node.js process in an undefined and potentially corrupted state, which is a significant reliability and security flaw, especially for a continuously running API gateway.
 
 Action:
-Fixed the global error handlers in `src/index.js` to call `process.exit(1)`, ensuring the process terminates safely and allows a process manager to restart it cleanly. Always ensure future Node.js applications follow this pattern rather than swallowing exceptions.
\ No newline at end of file
+Fixed the global error handlers in `src/index.js` to call `process.exit(1)`, ensuring the process terminates safely and allows a process manager to restart it cleanly. Always ensure future Node.js applications follow this pattern rather than swallowing exceptions.
+## 2024-05-18 — Handle Large Payload Sizes for LLM APIS
+
+Learning:
+Unrestricted payload limits can cause Node.js processes to crash or run out of memory when dealing with large LLM prompts. `express.json()` doesn't have a large enough default payload limit for these contexts. Also, when payload size exceeds the limit, Express throws an `entity.too.large` error that needs to be explicitly caught and converted to a 413 response; otherwise, a generic 500 error is returned.
+
+Action:
+Increased the `express.json()` payload limit to `10mb` in `src/index.js` and added a specific error handler for `entity.too.large` errors to return a clean 413 Payload Too Large response.
diff --git a/src/index.js b/src/index.js
index 5332530..e01d9e5 100644
--- a/src/index.js
+++ b/src/index.js
@@ -20,10 +20,13 @@ process.on('unhandledRejection', (reason, promise) => {
 const app = express();
 app.use(helmet());
 app.use(cors());
-app.use(express.json());
+app.use(express.json({ limit: '10mb' }));
 
 // Handle invalid JSON gracefully
 app.use((err, req, res, next) => {
+  if (err.type === 'entity.too.large') {
+    return res.status(413).json({ error: 'Payload Too Large' });
+  }
   if (err instanceof SyntaxError && err.status === 400 && 'body' in err) {
     return res.status(400).json({ error: 'Invalid JSON payload' });
   }
diff --git a/tests/api.test.js b/tests/api.test.js
index e184779..0d310b9 100644
--- a/tests/api.test.js
+++ b/tests/api.test.js
@@ -46,6 +46,20 @@ test('POST /v1/chat/completions fails with invalid JSON gracefully', async () =>
   assert.strictEqual(res.body.error, 'Invalid JSON payload');
 });
 
+test('POST /v1/chat/completions returns 413 for payload > 10mb', async () => {
+  // Generate a payload larger than 10MB
+  const largeString = 'a'.repeat(10 * 1024 * 1024 + 100);
+  const res = await request(app)
+    .post('/v1/chat/completions')
+    .send({
+      model: 'gpt-4',
+      messages: [{ role: 'user', content: largeString }]
+    });
+
+  assert.strictEqual(res.status, 413);
+  assert.strictEqual(res.body.error, 'Payload Too Large');
+});
+
 test('Generic error handler returns 500 without leaking stack traces', async () => {
   const crypto = require('crypto');
   const originalRandomUUID = crypto.randomUUID;

From 9a0c041e5ff0a9ad58caf5331ae27c814af39eb5 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Mon, 23 Mar 2026 04:39:39 +0000
Subject: [PATCH 2/2] fix(api): Increase express.json payload limit to 10mb and
 handle entity.too.large

Increased the default payload limit of `express.json()` from 100kb to 10mb to
accommodate large LLM prompts. Also added explicit error handling for
`entity.too.large` errors, returning a standard 413 Payload Too Large
JSON response instead of falling through to a generic 500 stack trace.
Added a test to verify this behavior.

Co-authored-by: shenald-dev <245350826+shenald-dev@users.noreply.github.com>