(Swift) Streaming AI with Automatic JavaScript AI Tool Function Calling

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• Tool function implementations are in JavaScript.
• The JavaScript also provides a tool registry and permissions.
• The JavaScript runs embedded within your application using Chilkat.Js.
• Tool calls are handled entirely within Chilkat. Your application does not need to manually check for function calls in the AI response. Internal to the Ask function, Chilkat will handle function calls by calling your registered JavaScript tools and will send results back to the AI model until the final response is received.

Note: This example requires Chilkat v11.4.0 or greater.

For more information, see https://www.chilkatsoft.com/ai_javascript_tool_function_calling.asp

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func chilkatTest() {
    var success: Bool = false

    // ----------------------------------------------------------------------------------
    // The Javascript file loaded here is shown at the bottom of this page.
    // -----------------------------------------------------------------------------------

    let sbJs = CkoStringBuilder()!
    success = sbJs.loadFile("qa_data/js_tools/horoscope_tools.js", charset: "utf-8")
    if success == false {
        print("\(sbJs.lastErrorText!)")
        return
    }

    let ai = CkoAi()!

    // Register the tools that will be made available to the AI.
    var evalOnly: Bool = false
    var allowAllKeyword: Bool = true
    ai.registerJsTools(sbJs, evalOnly: evalOnly, allowAllKeyword: allowAllKeyword)

    // The provider can be "openai", "google", "claude", "grok", "mistral", "custom", etc.
    ai.provider = "openai"
    // Use your provider's API key.
    ai.apiKey = "MY_API_KEY"
    // Choose a model.
    ai.model = "gpt-5-mini"

    // Tool function calling must always occur within a conversation.
    var conversation_name: String? = "convo_astrology"
    var sysMessage: String? = "You are a helpful astrologer"
    var devMessage: String? = "Respond only with markdown."
    ai.newConvo(conversation_name, sysMsg: sysMessage, devMsg: devMessage)

    // Provide inputs
    ai.inputAddText("What is my horoscope? I am an Aquarius.")

    // Get the response in streaming mode.
    ai.streaming = true

    // In streaming mode, if we receive an AI event that is a request for tool use,
    // we'll need to make the call to the JavaScript and then continue with a followup Ask,
    // until the final response is received.

    let sbEventName = CkoStringBuilder()!
    let sbDelta = CkoStringBuilder()!
    let sbFullResponse = CkoStringBuilder()!

    // When PollAi returns with an event, it's highly unlikely the
    // call to NextAiEvent does not immediately return.  Setting a max
    // timeout is just a precaution..
    var maxWaitMs: Int = 5000

    var finished: Bool = false
    var numAsks: Int = 0
    // Set a max # of followup Asks to prevent any unexpected infinite looping.
    while !finished && (numAsks < 10) {

        // Send the request to the AI model.
        success = ai.ask("text")
        if success == false {
            print("\(ai.lastErrorText!)")
            return
        }

        var madeFunctionCalls: Bool = false
        var streamingDone: Bool = false

        while !streamingDone {
            var result: Int = ai.poll(false).intValue
            if result < 0 {
                print("\(ai.lastErrorText!)")
                print("Failed.")
                return
            }

            if result > 0 {
                // We have an event..
                success = ai.nextEvent(maxWaitMs, sbName: sbEventName, sbDelta: sbDelta)
                if success == false {
                    print("\(ai.lastErrorText!)")
                    return
                }

                // Is this an event where the AI is requesting a function call?
                if sbEventName.contentsEqual("js_function_call", caseSensitive: true) {
                    // Call the JavaScript function.
                    // We don't need to find the exact function and make the call.  
                    // We can simply pass the sbDelta (which contains information about the function to be called and the args).
                    // Chilkat will find the registered JavaScript function, call it, and add the results to the conversation.
                    // We indicate that function calls were made, which results in a followup Ask (in the outer loop).
                    success = ai.streamingJsToolCall(sbDelta)
                    if success == false {
                        // The JS function call failed.
                        streamingDone = true
                    }
                    else {
                        madeFunctionCalls = true
                    }

                }
                else {
                    if !sbEventName.contentsEqual("empty", caseSensitive: true) {
                        sbFullResponse.appendSb(sbDelta)

                        if sbEventName.contentsEqual("null_terminator", caseSensitive: true) {
                            streamingDone = true
                        }

                    }

                }

            }
            else {
                // No event arrived, so wait a short time rather than spin in a loop..
                ai.sleepMs(100)
            }

        }

        if !madeFunctionCalls {
            finished = true
        }

        numAsks = numAsks + 1
    }

    print("Full Response:")
    print("\(sbFullResponse.getAsString()!)")

}

// The namespace for the AI tool functions in this JavaScript source file.
// You must provide a namespace.
Example = {};

// ----------------------------
// Tool implementation functions
// -----------------------------
// Tool functions must ALWAYS have just a single argument, which is an object.

// The function name used here must match the "name" in the toolRegistry below.

// By grouping get_compatibility, get_horoscope, toolRegistry, and toolPermissions under the Example object, 
// you are "namespacing" them. This tells anyone reading the code (and the JavaScript engine itself) 
// that these tools belong together and prevents them from clashing with another function that might 
// also be named get_horoscope. 

Example.get_compatibility = function(arg) {
  return  `${arg.sign1} is compatible with ${arg.sign2} in a ${arg.relationship_type} way.`;
}

Example.get_horoscope = function(arg) {
  return  `${arg.sign} : Next Tuesday you will befriend a baby otter.`;
}


// -------------
// Tool Registry
// -------------
// The inputSchema.type must ALWAYS be "object".
// Use this format regardless of the AI provider (ChatGPT, Gemini, Claude, Grok, Mistral, etc.)
Example.toolRegistry = [
  {
    name: "get_horoscope",
    description: "Get today's horoscope for an astrological sign.",
    parameters: {
      properties: {
        sign: { type: "string", description: "An astrological sign like Taurus or Aquarius" }
      },
    }
  },
  {
      name: "get_compatibility",
      description: "Returns compatibility analysis between two zodiac signs, including a score and explanation.",
      parameters: {
        properties: {
          sign1: {
            type: "string", description: "The first zodiac sign (e.g., Aries, Taurus, Gemini)."
          },
          sign2: {
            type: "string", description: "The second zodiac sign (e.g., Aries, Taurus, Gemini)."
          },
          relationship_type: {
            type: "string", description: "Type of compatibility to evaluate. (e.g., romantic, friendship, professional, general)"
          },
          detail_level: {
            type: "string", description: "Level of detail in the response. (e.g., short, medium, detailed)"
          }
        }
      }
  }
];

Example.toolPermissions = [
	  {
	    name: "all",
	    perm: "sandbox",
	  }
	  		
	];
	
// Return the name of this toolset
// This tells Chilkat the namespace of this toolset.
"Example";