DelphiGemini – Google Gemini API Wrapper for Delphi

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New

• GetIt current version: 1.1.0
• Changelog v1.1.1
• Interactions
• Summary

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Two simple illustrative examples of synchronous text generation.

[!TIP] To obtain a Google API key, please refer to the following link.

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• Non streamed example :

    // uses Gemini, Gemini.Types, Gemini.Helpers
    // Client: IGemini;
  
    Client := TGeminiFactory.CreateInstance('GEMINI_API_KEY');
  
    // Json Payload
    var Params: TProc<TInteractionParams> :=
      procedure (Params: TInteractionParams)
      begin
        Params
          .Model('gemini-3-flash-preview')
          .Input('From which version of Delphi were multi-line strings introduced?' );
      end;
  
    Memo1.Lines.Add('Please wait...');
  
    //Synchronous example (non streamed)
    var Value := Client.Interactions.Create(Params);
  
    try
      for var Output in Value.Outputs do
        if Output.&Type = TContentType.text then
          Memo1.Lines.Text := Memo1.Text + Output.Text;
    finally
      Value.Free;
    end;
  

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• Streamed example

    // uses Gemini, Gemini.Types, Gemini.Helpers;
    // Client: IGemini;
  
    Client := TGeminiFactory.CreateInstance('GEMINI_API_KEY');
  
    // Json Payload
    var Params: TProc<TInteractionParams> :=
      procedure (Params: TInteractionParams)
      begin
        Params
          .Model('gemini-3-flash-preview')
          .Input('From which version of Delphi were multi-line strings introduced?' )
          .Stream;
      end;
  
    // Stream Callback
    var StreamCallBack: TInteractionEvent :=
      procedure (var Event: TInteractionStream; IsDone: Boolean; var Cancel: Boolean)
      begin
        if (not IsDone) and Assigned(Event) then
          begin
            if Event.EventType = content_delta then
              if Event.Delta.&Type = TContentType.Text then
                begin
                  Memo1.Lines.Text := Memo1.Text + Event.Delta.Text;
                  Application.ProcessMessages;
                end;
          end;
      end;
  
    //Synchronous example (streamed)
    Client.Interactions.CreateStream(Params, StreamCallBack);
  

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Summary

• Introduction
• Philosophy and Scope
• Documentation – Overview
• Going Further
• Functional Coverage
• Project Status
• License

Introduction

Built with Delphi 12 Community Edition (v12.1 Patch 1)
The wrapper itself is MIT-licensed.
You can compile and test it free of charge with Delphi CE; any recent commercial Delphi edition works as well.

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Delphi wrapper for the Google Gemini API, covering both direct generation generatedContent and advanced agentic workflows interactions.

This project provides a clear and structured Delphi abstraction over the public Gemini APIs, with native support for synchronous, asynchronous, and streaming execution.

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[!IMPORTANT]

This is an unofficial library. Google does not provide an official Delphi SDK for Gemini. This repository contains Delphi implementation over Google Gemini public API.

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Philosophy and Scope

The wrapper is built around a clear and intentional separation between Gemini’s two main endpoints, which serve fundamentally different purposes.

GenerateContent

• direct generation
• stateless execution
• text and multimodal inputs
• simple SSE streaming
• limited built-in tools

This endpoint is well suited for immediate generation scenarios, interactive user interfaces, and straightforward processing pipelines.

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Interactions

• resource-oriented API
• server-side persistent conversations
• agents and advanced tools
• structured outputs (JSON schema)
• orchestration and background execution
• event-based SSE streaming

This endpoint is designed for more complex workflows such as agent-based systems, research tasks, structured extraction, automation, and multi-step processing.

This distinction shapes the entire documentation structure and all provided examples.

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Documentation – Overview

The documentation is organized as a set of independent Markdown files, each covering a specific functional area.

Main Entry Points

• GenerateContent Text and multimodal generation, synchronous and asynchronous calls, streaming, payload construction, and basic tools.

• Interactions Stateful conversations, agents, tools, structured outputs, orchestration, and advanced streaming

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Going Further

Some cross-cutting or advanced features are intentionally documented outside the main sections to keep the core documentation focused and readable.

A dedicated entry point groups these topics: Going Further

This section links to documents covering:

• Model discovery
• Embeddings
• File management
• Caching
• etc...

Each topic is documented in its own Markdown file.

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Functional Coverage

| Domain / Feature | Supported | |----------------------------|:---------:| | Text generation | ● | | Multimodal (image, audio, video, PDF) | ● | | SSE streaming | ● | | Persistent conversations | ● | | Agents | ● | | Deep Research | ● | | Structured outputs | ● | | Model discovery | ● | | Batch processing | ● | | Caching | ● | | File management | ● | | Embeddings | ● | | Vector search / FileSearch | ● | | Video generation (Veo) | ● | | Image generation (Imagen) | ● | | Image generation (Nano Banana) | ● | | Function calling | ● | | Grounding with Google Search | ● | | Grounding with Google Map | ● | | Url context | ● | | File search | ● | | Code execution | ● | | Computer Use | ● | | Thinking and thought Signatures | ● |

• supported*: support provided by DelphiGemini

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Project Status

• The Google Gemini API is evolving rapidly
• The Interactions endpoint is still in beta on Google’s side
• The wrapper follows a pragmatic approach:
  • document what is stable
  • isolate what is evolving
  • avoid unnecessary duplication of the official documentation

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License

This project is licensed under the MIT License.