Update src/rag_engine.py

src/rag_engine.py

@@ -10,7 +10,7 @@ from langchain_core.runnables import RunnablePassthrough, RunnableParallel
 class ProjectRAGEngine:
     def __init__(self, api_key):
         self.embeddings = OpenAIEmbeddings(openai_api_key=api_key)
-        self.llm = ChatOpenAI(model="gpt-oss-120b", openai_api_key=api_key, temperature=0)
+        self.llm = ChatOpenAI(model="openai/gpt-oss-120b:free", openai_api_key=api_key, temperature=0)
         self.vector_store = None
 
     def process_documents(self, pdf_paths):