> ## 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.

# Simple Calculator Tool

> Function calling with a calculator tool

This mirrors the current Cookbook. The assistant first asks to call your function, then you return the result using `function_call_result`.

### 1) Initial request (expose calculator)

```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 127 + 349?"}],
    "functions": [{
      "name": "calculate_sum",
      "description": "Add two numbers together and return the sum",
      "parameters": {
        "type": "object",
        "properties": {
          "a": {"type": "number"},
          "b": {"type": "number"}
        },
        "required": ["a", "b"]
      }
    }]
  }'
```

The response includes a `type: "function_call"` with `function_call_id` and arguments.

### 2) Follow-up with the result

```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 127 + 349?"},
      {"type": "function_call", "function_call_id": "CALL_ID_FROM_STEP_1", "function_calls": [{
        "name": "calculate_sum", "input": {"a": 127, "b": 349}
      }]},
      {"type": "function_call_result", "function_call_id": "CALL_ID_FROM_STEP_1", "function_call_results": [476]}
    ],
    "functions": [{
      "name": "calculate_sum",
      "description": "Add two numbers together and return the sum",
      "parameters": {
        "type": "object",
        "properties": {"a": {"type": "number"}, "b": {"type": "number"}},
        "required": ["a", "b"]
      }
    }]
  }'
```

<Note>
  View source on GitHub → [1\_simple\_calculator.py](https://github.com/Norditech-AB/Incredible-API-Cookbook/blob/main/02-function-calling/1_simple_calculator.py)
</Note>