> ## Documentation Index
> Fetch the complete documentation index at: https://incredible-42686482-cursor-create-detailed-ai-agent-cookboo.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Function Calling

> Let the AI call your functions and use the results

This shows the two-step flow used by the current Cookbook: the model returns a function call first, you execute it locally, then send back a `function_call_result` for the final answer.

### 1) Initial request (expose your functions)

```bash
curl -X POST "https://api.incredible.one/v1/chat-completion" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $INCREDIBLE_API_KEY" \
  -d '{
    "model": "small-1",
    "stream": false,
    "messages": [
      {"role": "user", "content": "What is 25 + 17?"}
    ],
    "functions": [{
      "name": "add_numbers",
      "description": "Add two numbers together",
      "parameters": {
        "type": "object",
        "properties": {
          "a": {"type": "number", "description": "First number"},
          "b": {"type": "number", "description": "Second number"}
        },
        "required": ["a", "b"]
      }
    }]
  }'
```

The response will include a `type: "function_call"` item with a `function_call_id` and the arguments for `add_numbers`.

### 2) Send back the function result

Execute `add_numbers(a, b)` locally, then include both the function call item and a `function_call_result` in a follow-up request:

```bash
curl -X POST "https://api.incredible.one/v1/chat-completion" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $INCREDIBLE_API_KEY" \
  -d '{
    "model": "small-1",
    "stream": false,
    "messages": [
      {"role": "user", "content": "What is 25 + 17?"},
      {"type": "function_call", "function_call_id": "CALL_ID_FROM_STEP_1", "function_calls": [{
        "name": "add_numbers",
        "input": {"a": 25, "b": 17}
      }]},
      {"type": "function_call_result", "function_call_id": "CALL_ID_FROM_STEP_1", "function_call_results": [42]}
    ],
    "functions": [{
      "name": "add_numbers",
      "description": "Add two numbers together",
      "parameters": {
        "type": "object",
        "properties": {
          "a": {"type": "number"},
          "b": {"type": "number"}
        },
        "required": ["a", "b"]
      }
    }]
  }'
```

The assistant will return the final natural-language answer using the function result.

<Note>
  View source on GitHub → [5\_function\_calling.py](https://github.com/Norditech-AB/Incredible-API-Cookbook/blob/main/01-getting-started/5_function_calling.py)
</Note>