From ead623b904310993ca1a26d8f6ddd1aef03216ac Mon Sep 17 00:00:00 2001
From: Sergey Konovalov <Sergey.Konovalov@onlyoffice.com>
Date: Sun, 12 Oct 2025 15:28:04 +0300
Subject: [PATCH] [bug] Preserve Accept-Encoding from original request if not
 explicitly provided; Fix bug 77551

---
 DocService/sources/ai/aiProxyHandler.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/DocService/sources/ai/aiProxyHandler.js b/DocService/sources/ai/aiProxyHandler.js
index 491660cd..aba5b0ad 100644
--- a/DocService/sources/ai/aiProxyHandler.js
+++ b/DocService/sources/ai/aiProxyHandler.js
@@ -227,6 +227,11 @@ async function proxyRequest(req, res) {
     // Merge key in headers
     const headers = {...body.headers, ...providerHeaders};
 
+    // Preserve Accept-Encoding from original request if not explicitly provided
+    if (!headers['accept-encoding'] && req.headers['accept-encoding']) {
+      headers['accept-encoding'] = req.headers['accept-encoding'];
+    }
+
     // use proxy instead of direct request
     if (tenAiApiProxy) {
       const tenTokenEnableOutbox = ctx.getCfg('services.CoAuthoring.token.enable.request.outbox', cfgTokenEnableOutbox);