add: main.py

main.py

@@ -0,0 +1,96 @@
+import os
+import asyncio
+from langchain_openai import ChatOpenAI
+from langchain_core.messages import HumanMessage
+from langchain.tools import tool
+from deepagents import create_deep_agent
+from deepagents.backends import FilesystemBackend, LocalShellBackend, CompositeBackend
+import requests
+from bs4 import BeautifulSoup
+
+# LLM
+llm = ChatOpenAI(
+    model="openai/gpt-oss-20b:free",
+    base_url="https://openrouter.ai/api/v1",
+    api_key=os.getenv("OPENAI_API_KEY"),
+    temperature=0.0,
+)
+
+# Backend: workspace + output
+workspace_dir = "./workspace"
+output_dir = "./output"
+
+backend = CompositeBackend([
+    LocalShellBackend(workspace_dir=workspace_dir),
+    FilesystemBackend(root_dir=output_dir),
+])
+
+# Tools
+
+@tool
+def search_web(query: str) -> str:
+    """Search the web using DuckDuckGo and return the first result title."""
+    url = f"https://duckduckgo.com/html/?q={query}"
+    headers = {"User-Agent": "Mozilla/5.0"}
+    resp = requests.get(url, headers=headers, timeout=10)
+    resp.raise_for_status()
+    soup = BeautifulSoup(resp.text, "html.parser")
+    result = soup.select_one(".result__a")
+    return result.get_text() if result else "No results found"
+
+@tool
+def fetch_page(url: str) -> str:
+    """Fetch the content of a web page."""
+    headers = {"User-Agent": "Mozilla/5.0"}
+    resp = requests.get(url, headers=headers, timeout=10)
+    resp.raise_for_status()
+    return resp.text[:2000]  # return first 2000 chars
+
+@tool
+def write_file(file_path: str, content: str) -> str:
+    """Write content to a file in the output directory."""
+    backend.write_file(file_path, content)
+    return f"File written: {file_path}"
+
+@tool
+def read_file(file_path: str) -> str:
+    """Read content from a file in the output directory."""
+    return backend.read_file(file_path)
+
+@tool
+def list_files() -> str:
+    """List files in the output directory."""
+    files = []
+    for root, dirs, filenames in os.walk(output_dir):
+        for f in filenames:
+            files.append(os.path.relpath(os.path.join(root, f), output_dir))
+    return "\\n".join(files) if files else "No files found"
+
+# Agent
+agent = create_deep_agent(
+    model=llm,
+    tools=[search_web, fetch_page, write_file, read_file, list_files],
+    backend=backend,
+    system_prompt=(
+        "You are a research assistant. You can search the web, fetch pages, "
+        "create and read files in the output directory. "
+        "When you finish your task, list all files you created."
+    ),
+)
+
+async def main():
+    user_prompt = (
+        "Please research 'Python async programming', write a brief report "
+        "in report.txt explaining key concepts, and create a README.md "
+        "summarizing the steps taken. Then list the files you created."
+    )
+    result = await agent.ainvoke(
+        {"messages": [HumanMessage(content=user_prompt)]},
+        {"configurable": {"thread_id": "research-session"}},
+    )
+    # Print final assistant message
+    print("\\n=== Final Assistant Message ===")
+    print(result["messages"][-1].content)
+
+if __name__ == "__main__":
+    asyncio.run(main())