diff --git a/.env.example b/.env.example
index 4b7968cd..a2b51ca2 100644
--- a/.env.example
+++ b/.env.example
@@ -59,8 +59,8 @@ POLYMENTOR_API_URL=https://poly-mentor-bm2s.vercel.app
 POLYMENTOR_LEVEL=beginner
 # Optional legacy Groq fallback if you set ASSISTANT_PROVIDER=groq
 # GROQ_API_KEY=your_groq_api_key_here
-# GROQ_MODEL=llama-3.3-70b-versatile
-# GROQ_FALLBACK_MODEL=llama-3.1-8b-instant
+# GROQ_MODEL=openai/gpt-oss-120b
+# GROQ_FALLBACK_MODEL=openai/gpt-oss-20b
 ASSISTANT_RATE_LIMIT_MAX=20
 
 # Export PolyMentor prompts (MongoDB → Google Drive JSON)
diff --git a/src/modules/chat/services/groqService.js b/src/modules/chat/services/groqService.js
index 7651f391..d5b0efb7 100644
--- a/src/modules/chat/services/groqService.js
+++ b/src/modules/chat/services/groqService.js
@@ -13,9 +13,9 @@ function getGroqConfig() {
 
   return {
     apiKey,
-    primaryModel: process.env.GROQ_MODEL?.trim() || "llama-3.3-70b-versatile",
+    primaryModel: process.env.GROQ_MODEL?.trim() || "openai/gpt-oss-120b",
     fallbackModel:
-      process.env.GROQ_FALLBACK_MODEL?.trim() || "llama-3.1-8b-instant",
+      process.env.GROQ_FALLBACK_MODEL?.trim() || "openai/gpt-oss-20b",
   };
 }