feat: enable chat functionality through environment variable

.env.sample

@@ -1,3 +1,4 @@
+ENABLE_CHAT=false
 LOGGING_LEVEL=DEBUG
 ENABLE_GRADIO_DEPRECATION_WARNING=false
 USE_MODAL=false

README.md

@@ -34,7 +34,7 @@ uv run gradio app.py
 
 The Chat Tab is hidden by default, because it is not fully implemented yet.
 
-To enable it, change `with gr.TabItem("Chat", visible=False):` to `with gr.TabItem("Chat", visible=True):` in `app.py`.
+To enable it, change `ENABLE_CHAT` to `true` in your `.env` file.
 
 ### Modal
 

app.py

@@ -22,7 +22,11 @@ from unpredictable_lord.mcp_server.mcp_server import (
     init_game,
     list_available_advice,
 )
-from unpredictable_lord.settings import ENABLE_GRADIO_DEPRECATION_WARNING, LOGGING_LEVEL
+from unpredictable_lord.settings import (
+    ENABLE_CHAT,
+    ENABLE_GRADIO_DEPRECATION_WARNING,
+    LOGGING_LEVEL,
+)
 from unpredictable_lord.utils import get_tool_prefix, update_guide_with_tool_prefix
 
 # Configure logging level from environment variable
@@ -66,9 +70,11 @@ with gr.Blocks(title="Unpredictable Lord") as demo:
     chat_session_id = gr.State(value=None)
     chat_system_instructions = gr.State(value="")
 
-    with gr.Tabs(selected="mcp_server"):
+    SELECTED_TAB = "chat" if ENABLE_CHAT else "mcp_server"
+
+    with gr.Tabs(selected=SELECTED_TAB):
         # Chat Tab (hidden - not ready for release)
-        with gr.TabItem("Chat", visible=False):
+        with gr.TabItem("Chat", id="chat", visible=ENABLE_CHAT):
             with gr.Row():
                 # Left column: Chat interface
                 with gr.Column(scale=3):

src/unpredictable_lord/chat/chat.py

@@ -15,7 +15,7 @@ from unpredictable_lord.chat.chat_tools import (
     execute_tool_calls,
     extract_tool_calls,
 )
-from unpredictable_lord.settings import USE_MODAL
+from unpredictable_lord.settings import ENABLE_CHAT, USE_MODAL
 
 logger = logging.getLogger(__name__)
 
@@ -24,10 +24,14 @@ logger = logging.getLogger(__name__)
 # Higher values allow for complex multi-step reasoning if needed
 MAX_AGENT_ITERATIONS = 3
 
+if not ENABLE_CHAT:
+    logger.info("Chat functionality is disabled.")
 
-if USE_MODAL:
+elif USE_MODAL:
     import modal
 
+    logger.info("Using Modal LLM backend for chat")
+
     APP_NAME = "unpredictable-lord"
     _generate_stream = modal.Function.from_name(APP_NAME, "generate_stream")
 
@@ -38,6 +42,8 @@ if USE_MODAL:
 else:
     from unpredictable_lord.chat.llm_zerogpu import generate_stream as _generate_stream
 
+    logger.info("Using ZeroGPU LLM backend for chat")
+
     async def generate_stream(input_tokens):
         logger.info("Calling ZeroGPU LLM generate_stream (sync wrapper)")
         # Note: This blocks the event loop, but is acceptable for ZeroGPU/Spaces

src/unpredictable_lord/settings.py

@@ -4,6 +4,7 @@ from dotenv import load_dotenv
 
 load_dotenv()
 
+ENABLE_CHAT = os.getenv("ENABLE_CHAT", "false").lower() == "true"
 LOGGING_LEVEL = os.getenv("LOGGING_LEVEL", "INFO").upper()
 ENABLE_GRADIO_DEPRECATION_WARNING = (
     os.getenv("ENABLE_GRADIO_DEPRECATION_WARNING", "false").lower() == "true"