Add configurable num_ctx option

src/chat.py

@@ -5,7 +5,7 @@ import json
 
 from ollama import AsyncClient, ChatResponse, Message
 
-from .config import MAX_TOOL_CALL_DEPTH, MODEL_NAME, OLLAMA_HOST
+from .config import MAX_TOOL_CALL_DEPTH, MODEL_NAME, NUM_CTX, OLLAMA_HOST
 from .db import Conversation, Message as DBMessage, User, _db, init_db
 from .log import get_logger
 from .schema import Msg
@@ -78,6 +78,7 @@ class ChatSession:
             messages=messages,
             think=think,
             tools=[add_two_numbers, execute_python],
+            options={"num_ctx": NUM_CTX},
         )
 
     async def _handle_tool_calls(

src/config.py

@@ -6,3 +6,4 @@ from typing import Final
 MODEL_NAME: Final[str] = os.getenv("OLLAMA_MODEL", "qwen3")
 OLLAMA_HOST: Final[str] = os.getenv("OLLAMA_HOST", "http://localhost:11434")
 MAX_TOOL_CALL_DEPTH: Final[int] = 5
+NUM_CTX: Final[int] = int(os.getenv("OLLAMA_NUM_CTX", "4096"))