Replace ChatOpenAI with ChatDeepSeek in model.

agent/nodes.py

@@ -8,6 +8,7 @@ from langchain_core.messages import BaseMessage
 from langchain_core.language_models.base import LanguageModelInput
 from langchain_google_genai import ChatGoogleGenerativeAI
 from langchain_openai import ChatOpenAI
+from langchain_deepseek import ChatDeepSeek
 from pydantic import BaseModel, Field, SecretStr
 from agent.prompts import get_system_prompt
 from agent.state import State
@@ -38,19 +39,25 @@ def _get_model() -> BaseChatModel:
     #     model="gemini-2.5-pro"
     # )
 
-    api_key = os.getenv(API_KEY_ENV_VAR)
+    # api_key = os.getenv(API_KEY_ENV_VAR)
 
-    return ChatOpenAI(
-        api_key=SecretStr(api_key) if api_key else None,
-        base_url=API_BASE_URL,
-        model=MODEL_NAME,
+    # return ChatOpenAI(
+    #     api_key=SecretStr(api_key) if api_key else None,
+    #     base_url=API_BASE_URL,
+    #     model=MODEL_NAME,
+    #     temperature=MODEL_TEMPERATURE if MODEL_TEMPERATURE else 0.0,
+    #     rate_limiter=_rate_limiter,
+    #     metadata={
+    #         "reasoning": {
+    #             "effort": "high"  # Use high reasoning effort
+    #         }
+    #     }
+    # )
+
+    return ChatDeepSeek(
+        model="deepseek-chat",
         temperature=MODEL_TEMPERATURE if MODEL_TEMPERATURE else 0.0,
-        rate_limiter=_rate_limiter,
-        metadata={
-            "reasoning": {
-                "effort": "high"  # Use high reasoning effort
-            }
-        }
+        max_retries=2,
     )
 
 def _get_tools() -> list[BaseTool]: