Defining function calling

Developing AI Systems with the OpenAI API

Francesca Donadoni

Curriculum Manager, DataCamp

OpenAI's tools

Can be used to return more specific information
Can define a more precise structure
Enhances the capabilities of the API call

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OpenAI's tools

A diagram showing a user message sent to the OpenAI API with a response connected to a smart home

OpenAI's tools

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What is function calling?

response = client.chat.completions.create(
  model="gpt-4o-mini",
  messages=[
   {"role": "user", 
   "content": "Please write down four trees with their scientific names in json."}
 ],
  response_format={"type": "json_object"}
)
print(response.choices[0].message.content)

{"trees": [{"common_name": "Oak", "scientific_name": "Quercus"}, { "common_name": 
"Maple", "scientific_name": "Acer"}, {"common_name": "Pine", "scientific_name": 
"Pinus"}, {"common_name": "Birch", "scientific_name": "Betula"}]}

Why use function calling?

{"trees": [
           {"common_name": "Oak", 
           "scientific_name": "Quercus"}, 
           { "common_name": "Maple", 
           "scientific_name": "Acer"}, 
           {"common_name": "Pine", 
           "scientific_name": "Pinus"}, 
           {"common_name": "Birch", 
           "scientific_name": "Betula"}
           ]
}

{"Oak": "Quercus",
 "Maple": "Acer",
 "Pine": "Pinus", 
 "Birch": "Betula"}

Use cases for function calling

Going from unstructured to consistent structured output

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Use cases for function calling

Calling multiple functions to provide complex responses

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Use cases for function calling

Calling external APIs

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Let's practice!

Developing AI Systems with the OpenAI API