openai.openai-go/examples/chat-completion-tool-calling/main.go

package main

import (
	"context"
	"encoding/json"
	"fmt"

	"github.com/openai/openai-go/v3"
)

func main() {
	client := openai.NewClient()

	ctx := context.Background()

	question := "What is the weather in New York City?"

	print("> ")
	println(question)

	params := openai.ChatCompletionNewParams{
		Messages: []openai.ChatCompletionMessageParamUnion{
			openai.UserMessage(question),
		},
		Tools: []openai.ChatCompletionToolUnionParam{
			openai.ChatCompletionFunctionTool(openai.FunctionDefinitionParam{
				Name:        "get_weather",
				Description: openai.String("Get weather at the given location"),
				Parameters: openai.FunctionParameters{
					"type": "object",
					"properties": map[string]any{
						"location": map[string]string{
							"type": "string",
						},
					},
					"required": []string{"location"},
				},
			}),
		},
		Seed:  openai.Int(0),
		Model: openai.ChatModelGPT4o,
	}

	// Make initial chat completion request
	completion, err := client.Chat.Completions.New(ctx, params)
	if err != nil {
		panic(err)
	}

	toolCalls := completion.Choices[0].Message.ToolCalls

	// Return early if there are no tool calls
	if len(toolCalls) == 0 {
		fmt.Printf("No function call")
		return
	}

	// If there is a was a function call, continue the conversation
	params.Messages = append(params.Messages, completion.Choices[0].Message.ToParam())
	for _, toolCall := range toolCalls {
		if toolCall.Function.Name == "get_weather" {
			// Extract the location from the function call arguments
			var args map[string]interface{}
			err := json.Unmarshal([]byte(toolCall.Function.Arguments), &args)
			if err != nil {
				panic(err)
			}
			location := args["location"].(string)

			// Simulate getting weather data
			weatherData := getWeather(location)

			// Print the weather data
			fmt.Printf("Weather in %s: %s\n", location, weatherData)

			params.Messages = append(params.Messages, openai.ToolMessage(weatherData, toolCall.ID))
		}
	}

	completion, err = client.Chat.Completions.New(ctx, params)
	if err != nil {
		panic(err)
	}

	println(completion.Choices[0].Message.Content)
}

// Mock function to simulate weather data retrieval
func getWeather(location string) string {
	// In a real implementation, this function would call a weather API
	return "Sunny, 25°C"
}