Delphi DLL

Streaming AI with Automatic JavaScript AI Tool Function Calling

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Demonstrates how to get AI responses in streaming mode, including possible tool function calling using Chilkat with embedded Chilkat.Js JavaScript. Automatic JavaScript tool calls are characterized by:

• 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.

Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Ai, StringBuilder;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
sbJs: HCkStringBuilder;
ai: HCkAi;
evalOnly: Boolean;
allowAllKeyword: Boolean;
conversation_name: PWideChar;
sysMessage: PWideChar;
devMessage: PWideChar;
sbEventName: HCkStringBuilder;
sbDelta: HCkStringBuilder;
sbFullResponse: HCkStringBuilder;
maxWaitMs: Integer;
finished: Boolean;
numAsks: Integer;
madeFunctionCalls: Boolean;
streamingDone: Boolean;
result: Integer;

begin
success := False;

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

sbJs := CkStringBuilder_Create();
success := CkStringBuilder_LoadFile(sbJs,'qa_data/js_tools/horoscope_tools.js','utf-8');
if (success = False) then
  begin
    Memo1.Lines.Add(CkStringBuilder__lastErrorText(sbJs));
    Exit;
  end;

ai := CkAi_Create();

// Register the tools that will be made available to the AI.
evalOnly := False;
allowAllKeyword := True;
CkAi_RegisterJsTools(ai,sbJs,evalOnly,allowAllKeyword);

// The provider can be "openai", "google", "claude", "grok", "mistral", "custom", etc.
CkAi_putProvider(ai,'openai');
// Use your provider's API key.
CkAi_putApiKey(ai,'MY_API_KEY');
// Choose a model.
CkAi_putModel(ai,'gpt-5-mini');

// Tool function calling must always occur within a conversation.
conversation_name := 'convo_astrology';
sysMessage := 'You are a helpful astrologer';
devMessage := 'Respond only with markdown.';
CkAi_NewConvo(ai,conversation_name,sysMessage,devMessage);

// Provide inputs
CkAi_InputAddText(ai,'What is my horoscope? I am an Aquarius.');

// Get the response in streaming mode.
CkAi_putStreaming(ai,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.

sbEventName := CkStringBuilder_Create();
sbDelta := CkStringBuilder_Create();
sbFullResponse := CkStringBuilder_Create();

// 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..
maxWaitMs := 5000;

finished := False;
numAsks := 0;
// Set a max # of followup Asks to prevent any unexpected infinite looping.
while not finished and (numAsks < 10) do
  begin

    // Send the request to the AI model.
    success := CkAi_Ask(ai,'text');
    if (success = False) then
      begin
        Memo1.Lines.Add(CkAi__lastErrorText(ai));
        Exit;
      end;

    madeFunctionCalls := False;
    streamingDone := False;

    while not streamingDone do
      begin
        result := CkAi_PollAi(ai,False);
        if (result < 0) then
          begin
            Memo1.Lines.Add(CkAi__lastErrorText(ai));
            Memo1.Lines.Add('Failed.');
            Exit;
          end;
        if (result > 0) then
          begin
            // We have an event..
            success := CkAi_NextAiEvent(ai,maxWaitMs,sbEventName,sbDelta);
            if (success = False) then
              begin
                Memo1.Lines.Add(CkAi__lastErrorText(ai));
                Exit;
              end;

            // Is this an event where the AI is requesting a function call?
            if (CkStringBuilder_ContentsEqual(sbEventName,'js_function_call',True)) then
              begin
                // 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 := CkAi_StreamingJsToolCall(ai,sbDelta);
                if (success = False) then
                  begin
                    // The JS function call failed.
                    streamingDone := True;
                  end
                else
                  begin
                    madeFunctionCalls := True;
                  end;
              end
            else
              begin
                if (not CkStringBuilder_ContentsEqual(sbEventName,'empty',True)) then
                  begin
                    CkStringBuilder_AppendSb(sbFullResponse,sbDelta);

                    if (CkStringBuilder_ContentsEqual(sbEventName,'null_terminator',True)) then
                      begin
                        streamingDone := True;
                      end;
                  end;
              end;

          end
        else
          begin
            // No event arrived, so wait a short time rather than spin in a loop..
            CkAi_SleepMs(ai,100);
          end;

      end;

    if (not madeFunctionCalls) then
      begin
        finished := True;
      end;

    numAsks := numAsks + 1;
  end;

Memo1.Lines.Add('Full Response:');
Memo1.Lines.Add(CkStringBuilder__getAsString(sbFullResponse));

CkStringBuilder_Dispose(sbJs);
CkAi_Dispose(ai);
CkStringBuilder_Dispose(sbEventName);
CkStringBuilder_Dispose(sbDelta);
CkStringBuilder_Dispose(sbFullResponse);

end;