TsgcAIChat Documents and PDF

How TsgcAIChat sends PDF documents and images with a message.

Introduction

TsgcAIChat can send PDF documents and images together with a user message, so the model answers about their content: summarise a contract, answer a question about a report or read the total of an invoice. The documents are sent as base64 data with their media type, and they are stored in the conversation history together with the message.

Methods

Method	Description
ChatWithDocument	Sends one PDF or image file with the message.
ChatWithDocumentBase64	Sends one document already encoded as base64, with its media type.
ChatWithAttachments	Sends several documents, in order, with the message.
ChatJSONWithAttachments	Same as ChatJSON, with the documents on the user message, to get the answer as JSON.

Supported Providers

Images are accepted by every provider. PDF documents are accepted by OpenAI, Anthropic and Gemini; DeepSeek, Grok, Mistral and Ollama accept images only, and sending them a PDF raises EsgcAIChat, which ChatWithDocument and ChatWithAttachments report through OnChatError. The model must support vision (for example gpt-4o-mini, a Claude model or a Gemini model).

Provider	PDF	Images
aicpOpenAI	Yes	Yes
aicpAnthropic	Yes	Yes
aicpGemini	Yes	Yes
aicpDeepSeek	No	Yes
aicpGrok	No	Yes
aicpMistral	No	Yes
aicpOllama	No	Yes

TsgcAIChatAttachments

An owning list of TsgcAIChatAttachment items, each one with Base64, MediaType and FileName properties. It is declared in sgcAI_Chat.

Member	Description
`function Add(const aBase64, aMediaType: string; const aFileName: string = ''): TsgcAIChatAttachment;`	Adds a document already encoded as base64. aMediaType is for example `application/pdf` or `image/png`.
`function AddFile(const aFileName: string): TsgcAIChatAttachment;`	Reads the file, encodes it as base64 and takes the media type from the extension: .pdf, .png, .jpg, .jpeg, .gif or .webp. Any other extension raises EsgcAIChat.
`procedure Clear;`	Removes and frees every attachment.
`property Count: Integer;`	Number of attachments.
`property Items[aIndex: Integer]: TsgcAIChatAttachment;`	Attachment at a position. It is the default property.

The list passed to ChatWithAttachments or ChatJSONWithAttachments stays owned by the caller. The attachments are copied into the history, so the list can be freed after the call and the next messages of the conversation can still refer to the document.

Example

oChat.Provider := aicpAnthropic;
oChat.ChatOptions.ApiKey := 'API_KEY';
oChat.ChatOptions.Model := 'claude-sonnet-4-20250514';
ShowMessage(oChat.ChatWithDocument('Summarise this contract', 'contract.pdf'));

oAttachments := TsgcAIChatAttachments.Create;
Try
  oAttachments.AddFile('page1.png');
  oAttachments.AddFile('page2.png');
  ShowMessage(oChat.ChatWithAttachments('Compare both pages', oAttachments));
Finally
  oAttachments.Free;
End;