Pascal (Lazarus/Delphi)

Streaming AI with Automatic JavaScript AI Tool Function Calling

See more AI Examples

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.

Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Ai,
  Chilkat.StringBuilder;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  sbJs: TStringBuilder;
  ai: TAi;
  evalOnly: Boolean;
  allowAllKeyword: Boolean;
  conversation_name: string;
  sysMessage: string;
  devMessage: string;
  sbEventName: TStringBuilder;
  sbDelta: TStringBuilder;
  sbFullResponse: TStringBuilder;
  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 := TStringBuilder.Create;
  success := sbJs.LoadFile('qa_data/js_tools/horoscope_tools.js','utf-8');
  if (success = False) then
    begin
      WriteLn(sbJs.LastErrorText);
      Exit;
    end;

  ai := TAi.Create;

  //  Register the tools that will be made available to the AI.
  evalOnly := False;
  allowAllKeyword := True;
  ai.RegisterJsTools(sbJs,evalOnly,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.
  conversation_name := 'convo_astrology';
  sysMessage := 'You are a helpful astrologer';
  devMessage := 'Respond only with markdown.';
  ai.NewConvo(conversation_name,sysMessage,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.

  sbEventName := TStringBuilder.Create;
  sbDelta := TStringBuilder.Create;
  sbFullResponse := TStringBuilder.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 := ai.Ask('text');
      if (success = False) then
        begin
          WriteLn(ai.LastErrorText);
          Exit;
        end;

      madeFunctionCalls := False;
      streamingDone := False;

      while not streamingDone do
        begin
          result := ai.PollAi(False);
          if (result < 0) then
            begin
              WriteLn(ai.LastErrorText);
              WriteLn('Failed.');
              Exit;
            end;
          if (result > 0) then
            begin
              //  We have an event..
              success := ai.NextAiEvent(maxWaitMs,sbEventName,sbDelta);
              if (success = False) then
                begin
                  WriteLn(ai.LastErrorText);
                  Exit;
                end;

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

                      if (sbEventName.ContentsEqual('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..
              ai.SleepMs(100);
            end;

        end;

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

      numAsks := numAsks + 1;
    end;

  WriteLn('Full Response:');
  WriteLn(sbFullResponse.GetAsString());


  sbJs.Free;
  ai.Free;
  sbEventName.Free;
  sbDelta.Free;
  sbFullResponse.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.