tools/
tools.rs

1use gemini_rust::{
2    Content, FunctionCallingMode, FunctionDeclaration, FunctionParameters, Gemini, Message,
3    PropertyDetails, Role, Tool,
4};
5use serde_json::json;
6use std::env;
7
8#[tokio::main]
9async fn main() -> Result<(), Box<dyn std::error::Error>> {
10    // Get API key from environment variable
11    let api_key = env::var("GEMINI_API_KEY").expect("GEMINI_API_KEY environment variable not set");
12
13    // Create client
14    let client = Gemini::new(api_key);
15
16    println!("--- Tools example with multiple functions ---");
17
18    // Define a weather function
19    let get_weather = FunctionDeclaration::new(
20        "get_weather",
21        "Get the current weather for a location",
22        FunctionParameters::object()
23            .with_property(
24                "location",
25                PropertyDetails::string("The city and state, e.g., San Francisco, CA"),
26                true,
27            )
28            .with_property(
29                "unit",
30                PropertyDetails::enum_type("The unit of temperature", ["celsius", "fahrenheit"]),
31                false,
32            ),
33    );
34
35    // Define a calculator function
36    let calculate = FunctionDeclaration::new(
37        "calculate",
38        "Perform a calculation",
39        FunctionParameters::object()
40            .with_property(
41                "operation",
42                PropertyDetails::enum_type(
43                    "The mathematical operation to perform",
44                    ["add", "subtract", "multiply", "divide"],
45                ),
46                true,
47            )
48            .with_property("a", PropertyDetails::number("The first number"), true)
49            .with_property("b", PropertyDetails::number("The second number"), true),
50    );
51
52    // Create a tool with multiple functions
53    let tool = Tool::with_functions(vec![get_weather, calculate]);
54
55    // Create a request with tool functions
56    let response = client
57        .generate_content()
58        .with_system_prompt(
59            "You are a helpful assistant that can check weather and perform calculations.",
60        )
61        .with_user_message("What's 42 times 12?")
62        .with_tool(tool)
63        .with_function_calling_mode(FunctionCallingMode::Any)
64        .execute()
65        .await?;
66
67    // Process function calls
68    if let Some(function_call) = response.function_calls().first() {
69        println!(
70            "Function call: {} with args: {}",
71            function_call.name, function_call.args
72        );
73
74        // Handle different function calls
75        match function_call.name.as_str() {
76            "calculate" => {
77                let operation: String = function_call.get("operation")?;
78                let a: f64 = function_call.get("a")?;
79                let b: f64 = function_call.get("b")?;
80
81                println!("Calculation: {} {} {}", a, operation, b);
82
83                let result = match operation.as_str() {
84                    "add" => a + b,
85                    "subtract" => a - b,
86                    "multiply" => a * b,
87                    "divide" => a / b,
88                    _ => panic!("Unknown operation"),
89                };
90
91                let function_response = json!({
92                    "result": result,
93                })
94                .to_string();
95
96                // Based on the curl example, we need to structure the conversation properly:
97                // 1. A user message with the original query
98                // 2. A model message containing the function call
99                // 3. A user message containing the function response
100
101                // Construct conversation following the exact curl pattern
102                let mut conversation = client.generate_content();
103
104                // 1. Add user message with original query and system prompt
105                conversation = conversation
106                    .with_system_prompt("You are a helpful assistant that can check weather and perform calculations.")
107                    .with_user_message("What's 42 times 12?");
108
109                // 2. Create model content with function call
110                let model_content = Content::function_call((*function_call).clone());
111
112                // Add as model message
113                let model_message = Message {
114                    content: model_content,
115                    role: Role::Model,
116                };
117                conversation = conversation.with_message(model_message);
118
119                // 3. Add user message with function response
120                conversation =
121                    conversation.with_function_response_str("calculate", function_response)?;
122
123                // Execute the request
124                let final_response = conversation.execute().await?;
125
126                println!("Final response: {}", final_response.text());
127            }
128            "get_weather" => {
129                let location: String = function_call.get("location")?;
130                let unit = function_call
131                    .get::<String>("unit")
132                    .unwrap_or_else(|_| String::from("celsius"));
133
134                println!("Weather request for: {}, Unit: {}", location, unit);
135
136                let weather_response = json!({
137                    "temperature": 22,
138                    "unit": unit,
139                    "condition": "sunny"
140                })
141                .to_string();
142
143                // Based on the curl example, we need to structure the conversation properly:
144                // 1. A user message with the original query
145                // 2. A model message containing the function call
146                // 3. A user message containing the function response
147
148                // Construct conversation following the exact curl pattern
149                let mut conversation = client.generate_content();
150
151                // 1. Add user message with original query and system prompt
152                conversation = conversation
153                    .with_system_prompt("You are a helpful assistant that can check weather and perform calculations.")
154                    .with_user_message("What's 42 times 12?");
155
156                // 2. Create model content with function call
157                let model_content = Content::function_call((*function_call).clone());
158
159                // Add as model message
160                let model_message = Message {
161                    content: model_content,
162                    role: Role::Model,
163                };
164                conversation = conversation.with_message(model_message);
165
166                // 3. Add user message with function response
167                conversation =
168                    conversation.with_function_response_str("get_weather", weather_response)?;
169
170                // Execute the request
171                let final_response = conversation.execute().await?;
172
173                println!("Final response: {}", final_response.text());
174            }
175            _ => println!("Unknown function"),
176        }
177    } else {
178        println!("No function calls in the response.");
179        println!("Response: {}", response.text());
180    }
181
182    Ok(())
183}
tools/tools.rs

tools/
tools.rs
