Agent with tools

You need: a separate fetch_... key with a spend limit and an allowed-models list (create one), Python 3.10+ and pip install openai.

1. 1
   Save the code

   File agent.py. Tools: get_weather (a stub instead of a weather service) and calculate (a calculator).

   agent.pyCopy

   """
   Agent with tools: the model decides which function to call.
   pip install openai
   python agent.py "What is the weather in London and in Madrid? How much warmer is Madrid?"
   """
   import ast
   import json
   import operator
   import os
   import sys
   
   from openai import OpenAI
   
   MODEL = "deepseek-v4.1-flash"  # or "claude-haiku-5-5", "gpt-6-luna"

   Show all code · 169 lines
2. 2
   Run it

   bashCopy

   export ZUKKO_API_KEY="fetch_your_key"
   python agent.py "What is the weather in London and in Madrid? How much warmer is Madrid?"

   The model asks for the weather in both cities, then for the difference, then answers. Every call is printed.

3. 3
   Add web search (optional)

   Paste the code into agent.py before if __name__ == "__main__":, and add "call web_search for fresh facts" to SYSTEM.

   pythonCopy

   import urllib.error
   import urllib.request
   
   
   def web_search(query: str) -> dict:
       request = urllib.request.Request(
           "https://api.zukko.pro/v1/web-search",
           data=json.dumps({"query": query, "max_results": 5}).encode(),
           headers={
               "Authorization": f"Bearer {os.environ['ZUKKO_API_KEY']}",
               "Content-Type": "application/json",
           },
       )
       try:

   Show all code · 37 lines

   Up to 10 results, about $0.0003–0.0005 per search, counts toward the key's limits. Parameters: POST /v1/web-search.

1The agent loop

1. Send the conversation with the tools parameter.
2. Got tool_calls? Run each call and return the result as a message with the tool role and the matching tool_call_id. Go back to step 1.
3. No tool_calls — content holds the final answer.

MAX_STEPS and MAX_COST_USD stop the agent if it goes in circles. To add your own tool: a function in TOOL_FUNCTIONS and a description in TOOLS.

2Models

Tested through /v1/chat/completions. With the Anthropic SDK and /v1/messages, tools are passed the same way as in the Anthropic API.

3If it doesn't work