Updated agent to use modern LangChain API and fixed tool definitions.: update src/agent.py

src/agent.py

@@ -1,38 +1,45 @@
 import os
-from typing import Dict
+from typing import Dict, List
 
-from langchain.agents import AgentExecutor, create_openai_tools_agent
+from langchain.agents import AgentExecutor, create_agent
 from langchain_ollama import Ollama
 from langchain_core.prompts import ChatPromptTemplate
 from langchain_core.messages import HumanMessage
+from langchain.tools import Tool
 
 from src.utils import search_course_docs
 from src.mcp_tool import fetch_course_meta
 
-# Define tools
+# Define tool functions
 
-def chroma_tool(query: str):
+def chroma_tool(query: str) -> List[str]:
+    """Search FAQ documents in Chroma. Use when question about course content."""
     return search_course_docs(query)
 
-# Wrap MCP tool
 
-def mcp_tool(query: str):
+def mcp_tool(query: str) -> Dict:
+    """Get course metadata such as schedule. Use when question about schedule or instructor."""
     return fetch_course_meta(query)
 
-# Simple tool registry
-TOOL_DEFINITIONS = {
-    "search_course_docs": {
-        "func": chroma_tool,
-        "description": "Search FAQ documents in Chroma. Use when question about course content.",
-    },
-    "fetch_course_meta": {
-        "func": mcp_tool,
-        "description": "Get course metadata such as schedule. Use when question about schedule or instructor.",
-    },
-}
+# Create Tool objects
+TOOL_DEFINITIONS = [
+    Tool.from_function(
+        func=chroma_tool,
+        name="search_course_docs",
+        description="Search FAQ documents in Chroma. Use when question about course content.",
+    ),
+    Tool.from_function(
+        func=mcp_tool,
+        name="fetch_course_meta",
+        description="Get course metadata such as schedule. Use when question about schedule or instructor.",
+    ),
+]
 
 # Prompt template
-SYSTEM_PROMPT = """You are a FAQ bot for the course. Use only the tools provided. Do not call both tools unless necessary. Indicate source in your answer: 'source: chroma' or 'source: mcp_meta'."""
+SYSTEM_PROMPT = (
+    "You are a FAQ bot for the course. Use only the tools provided. Do not call both tools unless necessary."
+    " Indicate source in your answer: 'source: chroma' or 'source: mcp_meta'."
+)
 
 PROMPT = ChatPromptTemplate.from_messages([
     ("system", SYSTEM_PROMPT),
@@ -41,8 +48,8 @@ PROMPT = ChatPromptTemplate.from_messages([
 
 # Create agent
 llm = Ollama(model="llama2")
-agent = create_openai_tools_agent(llm, TOOL_DEFINITIONS, PROMPT)
-executor = AgentExecutor(agent=agent, tools=list(TOOL_DEFINITIONS.values()), verbose=True)
+agent = create_agent(llm, TOOL_DEFINITIONS, PROMPT)
+executor = AgentExecutor(agent=agent, tools=TOOL_DEFINITIONS, verbose=True)
 
 # CLI entry point
 if __name__ == "__main__":