Create agent.py

agent.py

@@ -0,0 +1,122 @@
+import os
+import hashlib
+import json
+import logging
+from smolagents import CodeAgent, tool
+from huggingface_hub import InferenceClient
+
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+# Cache for answers (persists between runs)
+CACHE_FILE = "answer_cache.json"
+if os.path.exists(CACHE_FILE):
+    with open(CACHE_FILE) as f:
+        answer_cache = json.load(f)
+else:
+    answer_cache = {}
+
+def save_cache():
+    with open(CACHE_FILE, "w") as f:
+        json.dump(answer_cache, f)
+
+# ---------- Tools ----------
+@tool
+def calculator(expression: str) -> str:
+    """
+    Safely evaluate a mathematical expression.
+
+    Args:
+        expression: A string containing a simple arithmetic expression (e.g., '2 + 2').
+
+    Returns:
+        The result as a string, or an error message if the expression is invalid.
+    """
+    allowed_chars = set("0123456789+-*/(). ")
+    if not all(c in allowed_chars for c in expression):
+        return "Error: Expression contains disallowed characters."
+    try:
+        # Restricted eval – only math allowed
+        result = eval(expression, {"__builtins__": {}}, {})
+        return str(result)
+    except Exception as e:
+        return f"Error: {e}"
+
+@tool
+def web_search(query: str) -> str:
+    """
+    Search the web for up-to-date information.
+
+    Args:
+        query: The search query string.
+
+    Returns:
+        A string containing up to three search result snippets with titles and URLs,
+        or an error message if the search fails.
+    """
+    try:
+        from duckduckgo_search import DDGS
+        with DDGS() as ddgs:
+            results = list(ddgs.text(query, max_results=3))
+        if not results:
+            return "No results found."
+        snippets = []
+        for r in results:
+            snippets.append(f"Title: {r['title']}\nBody: {r['body']}\nURL: {r['href']}")
+        return "\n\n".join(snippets)
+    except ImportError:
+        return "Web search tool not available: install duckduckgo-search"
+    except Exception as e:
+        return f"Search error: {e}"
+
+# ---------- Custom model that wraps HF InferenceClient ----------
+class CustomHFModel:
+    def __init__(self, model_id="HuggingFaceH4/zephyr-7b-beta"):
+        self.client = InferenceClient(model=model_id, token=os.getenv("HF_TOKEN"))
+        self.model_id = model_id
+
+    def __call__(self, messages, **kwargs):
+        """
+        Expected by smolagents: takes a list of messages
+        (e.g., [{"role": "user", "content": "..."}])
+        and returns the assistant's reply as a string.
+        """
+        response = self.client.chat_completion(
+            messages=messages,
+            max_tokens=500,
+            temperature=0.7,
+            **kwargs
+        )
+        return response.choices[0].message.content
+
+# ---------- Assemble the agent (once, at import) ----------
+tools = [calculator]
+try:
+    import duckduckgo_search
+    tools.append(web_search)
+    logger.info("Web search tool enabled.")
+except ImportError:
+    logger.warning("duckduckgo-search not installed, web_search disabled.")
+
+model = CustomHFModel()  # you can change the model_id if desired
+agent = CodeAgent(tools=tools, model=model)
+
+# ---------- The class expected by app.py ----------
+class CustomAgent:
+    def __call__(self, question: str) -> str:
+        """This method is called for each question."""
+        q_hash = hashlib.md5(question.encode()).hexdigest()
+        if q_hash in answer_cache:
+            logger.info(f"Cache hit for question: {question[:50]}...")
+            return answer_cache[q_hash]
+
+        logger.info(f"Processing question: {question[:50]}...")
+        try:
+            answer = agent.run(question)
+        except Exception as e:
+            logger.error(f"Agent error: {e}")
+            answer = f"Error: {e}"
+
+        answer_cache[q_hash] = answer
+        save_cache()
+        return answer