Using function calling

The Continue from conversation history endpoint allows you to use function calling in your applications.

Paddler uses the Hermes format for function calling and will validate your list of functions against the Hermes schema.

To use function calling, add your functions in the optional tools parameter in your request. It will then be added to the prompt according to the chat template used (usually to the system prompt) and processed by the model.

Let's take a look at a few examples of using function calling.

Get weather example

Payload

{
    "add_generation_prompt": true,
    "enable_thinking": true,
    "max_tokens": 400,
    "tools": [
        {
            "type": "function",
            "function": {
                "name": "get_weather",
                "description": "Get the current weather information for a specified location.",
                "parameters": {
                    "type": "object",
                    "properties": {
                        "location": {
                            "type": "string",
                            "description": "The city and state, e.g. San Francisco, CA"
                        },
                        "unit": {
                            "type": "string",
                            "enum": ["celsius", "fahrenheit"],
                            "description": "The temperature unit to use. Defaults to fahrenheit."
                        }
                    },
                    "required": ["location"]
                }
            }
        }
    ],
    "conversation_history": [
        {
            "role": "system",
            "content": "You are a helpful assistant that provides weather information"
        },
        {
            "role": "user",
            "content": "What's the weather like in New York City?"
        }
    ]
}

Response

<tool_call>
{
    "name": "get_weather",
    "arguments": {
        "location": "New York City, NY",
        "unit": "fahrenheit"
    }
}
</tool_call>

Manage zoo animals example

Payload

{
    "add_generation_prompt": true,
    "enable_thinking": true,
    "max_tokens": 4000,
    "tools": [
        {
            "type": "function",
            "function": {
                "name": "manage_zoo_animals",
                "description": "Create, read, update, or delete zoo animal records in the system.",
                "parameters": {
                    "type": "object",
                    "properties": {
                        "action": {
                            "type": "string",
                            "enum": ["create", "read", "update", "delete"],
                            "description": "The action to perform on the zoo animal record."
                        },
                        "animal": {
                            "type": "object",
                            "description": "The zoo animal record to create, read, update, or delete.",
                            "properties": {
                                "name": { 
                                    "type": "string", 
                                    "description": "The name of the animal." 
                                },
                                "species": { 
                                    "type": "string", 
                                    "description": "The species of the animal." 
                                },
                                "age": { 
                                    "type": "integer", 
                                    "description": "The age of the animal in years." 
                                }
                            },
                            "required": ["name", "species", "age"],
                            "additionalProperties": { "type": "string" }
                        }
                    },
                    "required": ["animal"]
                }
            }
        }
    ],
    "conversation_history": [
        {
            "role": "system",
            "content": "You are a helpful assistant that manages zoo"
        },
        {
            "role": "user",
            "content": "I need to register a new kangaroo, he's 2 years old, his name is Johnson"
        }
    ]
}

Response

<tool_call> 
{
    "name ": "manage_zoo_animals", 
    "arguments ": {
        "action ": "create", 
        "animal ": {
            "name ": "Johnson", 
            "species": "kangaroo", 
            "age": 2
        }
    } 
}
</tool_call>