openai_function_calling_weather_tool_with_multi_location.ts

1import OpenAI from "openai";
2
3const openai = new OpenAI();
4
5// Example dummy function which calls an external API or perform some logic
6function getCurrentWeather(location: string, unit: string = "celsius") {
7  if (location.toLowerCase().includes("tokyo")) {
8    return JSON.stringify({ location: "Tokyo", temperature: "10", unit: "celsius" });
9  } else if (location.toLowerCase().includes("san francisco")) {
10    return JSON.stringify({ location: "San Francisco", temperature: "72", unit: "fahrenheit" });
11  } else if (location.toLowerCase().includes("paris")) {
12    return JSON.stringify({ location: "Paris", temperature: "22", unit: "celsius" });
13  } else {
14    return JSON.stringify({ location, temperature: "unknown" });
15  }
16}
17
18async function main() {
19  const messages: OpenAI.Chat.ChatCompletionMessageParam[] = [
20    { role: "user", content: "What's the weather like in San Francisco, Tokyo, and Paris?" },
21  ];
22
23  const tools: OpenAI.Chat.ChatCompletionTool[] = [
24    {
25      type: "function",
26      function: {
27        name: "get_current_weather",
28        description: "Get the current weather in a given location",
29        parameters: {
30          type: "object",
31          properties: {
32            location: {
33              type: "string",
34              description: "The city and state, e.g. San Francisco, CA",
35            },
36            unit: { type: "string", enum: ["celsius", "fahrenheit"] },
37          },
38          required: ["location"],
39        },
40      },
41    },
42  ];
43
44  const response = await openai.chat.completions.create({
45    model: "gpt-4o",
46    messages: messages,
47    tools: tools,
48    tool_choice: "auto",
49  });
50
51  const responseMessage = response.choices[0].message;
52
53  // Check if the model wants to call a function
54  const toolCalls = responseMessage.tool_calls;
55  if (toolCalls) {
56    // Add the model's response to the conversation history
57    messages.push(responseMessage);
58
59    for (const toolCall of toolCalls) {
60      const functionName = toolCall.function.name;
61      const functionArgs = JSON.parse(toolCall.function.arguments);
62      
63      let functionResponse;
64      if (functionName === "get_current_weather") {
65        functionResponse = getCurrentWeather(
66          functionArgs.location,
67          functionArgs.unit
68        );
69      }
70
71      // Add the tool output to the conversation history
72      messages.push({
73        tool_call_id: toolCall.id,
74        role: "tool",
75        content: functionResponse,
76      });
77    }
78
79    // Get a final response from the model now that it has the tool outputs
80    const secondResponse = await openai.chat.completions.create({
81      model: "gpt-4o",
82      messages: messages,
83    });
84
85    console.log(secondResponse.choices[0].message.content);
86  }
87}
88
89main().catch(console.error);