In this short example, we want to show you how you can add with a minimal amount of effort automatic invoice data extraction to a Delphi app.
This is realized with the TMS AI Studio TTMSMCPCloudAI component and in this example, taking advantage of 3 possible LLMs: OpenAI, Gemini or Claude. 

How it works?

It is actually quite simple how to achieve this. We use the TTMSMCPCloudAI to send the PDF invoice and a prompt and we get in return a JSON object with the data we wanted to extract! 

An essential part is providing a good prompt. We have seen good results from the following prompt setup:

TMSMCPCloudAI1.Context.Text := 'Extract information from the PDF invoice and return as a JSON object';

TMSMCPCloudAI1.SystemRole.Text := 'You collect information from the PDF invoice and return it strictly as a JSON object with this exact structure: JSON object has following key-value pairs: "InvoiceDate","InvoiceNumber","VendorName","VendorAddress","VendorVATID","CustomerName","CustomerAddress","CustomerVATID", "ListofItems","ListOfPrices", "NetTotal", "Tax", "Total";'

You can see that we use the system role description where we specify what the expected output format is of the JSON object containing the critical invoice data. But combining everything in the context also turned out to be working. The main prompt is then just to "Extract information from the PDF invoice and return as a JSON object". The system role is used to specify what exact information we want from the invoice and as what key-value pairs it should be returned in the invoice.

begin
  TMSMCPCloudAI1.UploadFile(INVOICEPDF, aiftPDF);
end;

begin
  TMSMCPCloudAI1.Execute('process_invoice');
end;

begin
  TMSMCPCloudAI1.AddFile(INVOICEPDF, aiftPDF);
  TMSMCPCloudAI1.Execute('process_invoice');
end;

To select the LLM to be used for this operation is as sample as:

TMSMCPCloudAI.Service := aiClaude

The resulting output of the LLM is for this PDF invoice:

{
    "InvoiceDate": "05/09/2022",
    "InvoiceNumber": "FA2022-0001",
    "VendorName": "BV CRE8",
    "VendorAddress": "Diestersteenweg 462, 3680 Maaseik, Belgium",
    "VendorVATID": "BE0631922138",
    "CustomerName": "Comanage business user",
    "CustomerAddress": "",
    "CustomerVATID": "BE0631922138",
    "ListofItems": ["comanage business pakket"],
    "ListOfPrices": [150.00],
    "NetTotal": 150.00,
    "Tax": 31.50,
    "Total": 181.50
}

We tested this with a couple of sample invoice downloaded from the internet and the result was satisfying.
This is available as a VCL application. Note that it uses the TAdvPDFViewer component to show a preview of the PDF file selected.  The TAdvPDFViewer component is part of TMS VCL UI Pack. The sample project download also includes 3 sample PDF files for your testing.

Conclusion