diff --git a/backend/app/services/llm_service.py b/backend/app/services/llm_service.py
index 3c37f3e..324b3ab 100644
--- a/backend/app/services/llm_service.py
+++ b/backend/app/services/llm_service.py
@@ -99,11 +99,13 @@ class LLMGateway:
         """Estimate cost in cents. Rough pricing, adjustable."""
         # Per 1M tokens, in cents (1 USD = 100 cents)
         pricing = {
-            "gpt-4o": {"input": 250, "output": 1000},      # $2.50 / $10 per 1M
-            "gpt-4o-mini": {"input": 15, "output": 60},     # $0.15 / $0.60 per 1M
+            "gpt-4o": {"input": 250, "output": 1000},
+            "gpt-4o-mini": {"input": 15, "output": 60},
             "gpt-4-turbo": {"input": 1000, "output": 3000},
             "deepseek-chat": {"input": 14, "output": 28},
             "deepseek-reasoner": {"input": 55, "output": 219},
+            "deepseek-v4-flash": {"input": 14, "output": 28},
+            "qwen3.6-plus": {"input": 40, "output": 120},
         }
         rates = pricing.get(model, {"input": 15, "output": 60})  # default: cheap
         cost = (