function_calling/
function_calling.rs

1//! Function calling example with GPT-5
2//!
3//! This example shows how to use GPT-5 with function calling capabilities
4//! Run with: cargo run --example function_calling
5
6use gpt5::{Gpt5Client, Gpt5Model, Gpt5RequestBuilder, ReasoningEffort, Tool, VerbosityLevel};
7use serde_json::json;
8
9#[tokio::main]
10async fn main() -> Result<(), Box<dyn std::error::Error>> {
11    let api_key =
12        std::env::var("OPENAI_API_KEY").expect("Please set OPENAI_API_KEY environment variable");
13
14    let client = Gpt5Client::new(api_key);
15
16    // Define a simple calculator tool
17    let calculator_tool = Tool {
18        tool_type: "function".to_string(),
19        name: "calculate".to_string(),
20        description: "Perform basic arithmetic calculations".to_string(),
21        parameters: json!({
22            "type": "object",
23            "properties": {
24                "expression": {
25                    "type": "string",
26                    "description": "Mathematical expression to evaluate (e.g., '2 + 2', '10 * 5')"
27                }
28            },
29            "required": ["expression"]
30        }),
31    };
32
33    // Define a weather tool (mock)
34    let weather_tool = Tool {
35        tool_type: "function".to_string(),
36        name: "get_weather".to_string(),
37        description: "Get current weather information for a city".to_string(),
38        parameters: json!({
39            "type": "object",
40            "properties": {
41                "city": {
42                    "type": "string",
43                    "description": "The city name to get weather for"
44                }
45            },
46            "required": ["city"]
47        }),
48    };
49
50    println!("🧮 Testing calculator function...");
51
52    // Build a request with tools
53    let request = Gpt5RequestBuilder::new(Gpt5Model::Gpt5Nano)
54        .input("What is 15 * 8 + 42?")
55        .instructions("Use the calculator tool to solve this math problem")
56        .tools(vec![calculator_tool])
57        .tool_choice("auto")
58        .verbosity(VerbosityLevel::Medium)
59        .reasoning_effort(ReasoningEffort::Low)
60        .max_output_tokens(200)
61        .build();
62
63    // Send the request
64    let response = client.request(request).await?;
65
66    // Check for function calls
67    let function_calls = response.function_calls();
68    if !function_calls.is_empty() {
69        println!("🔧 Function calls made: {}", function_calls.len());
70        for call in function_calls {
71            println!("  Function: {}", call.name.as_deref().unwrap_or("unknown"));
72            println!("  Arguments: {}", call.arguments.as_deref().unwrap_or("{}"));
73        }
74    }
75
76    // Get text response
77    if let Some(text) = response.text() {
78        println!("🤖 Response: {}", text);
79    }
80
81    println!("\n🌤️ Testing weather function...");
82
83    // Test weather tool
84    let weather_request = Gpt5RequestBuilder::new(Gpt5Model::Gpt5Nano)
85        .input("What's the weather like in Tokyo?")
86        .instructions("Use the weather tool to get current conditions")
87        .tools(vec![weather_tool])
88        .tool_choice("auto")
89        .verbosity(VerbosityLevel::Low)
90        .reasoning_effort(ReasoningEffort::Low)
91        .max_output_tokens(150)
92        .build();
93
94    let weather_response = client.request(weather_request).await?;
95
96    let weather_calls = weather_response.function_calls();
97    if !weather_calls.is_empty() {
98        println!("🔧 Weather function calls made: {}", weather_calls.len());
99        for call in weather_calls {
100            println!("  Function: {}", call.name.as_deref().unwrap_or("unknown"));
101            println!("  Arguments: {}", call.arguments.as_deref().unwrap_or("{}"));
102        }
103    }
104
105    if let Some(text) = weather_response.text() {
106        println!("🤖 Response: {}", text);
107    }
108
109    Ok(())
110}
function_calling/function_calling.rs

function_calling/
function_calling.rs
