README

AIChat 9x

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An AI chat client for legacy Windows (95/NT), bridging the gap to modern AI APIs via a LAN proxy.

Table of Contents

• Introduction
• Architecture
• Quick Start
• Configuration
• Project Structure
• Technical Constraints

Introduction

AIChat 9x consists of two components:

1. AIChat Client — A Delphi 7 Windows desktop application using WinInet for HTTP requests, targeting legacy systems like Windows 95/NT that cannot run modern browsers.
2. AIChatProxy — A Python Flask HTTP proxy that forwards requests from the client to a remote AI API over HTTPS, handling GBK/UTF-8 encoding conversion.

Why a proxy? Legacy Windows systems lack modern TLS support and cannot connect to HTTPS APIs directly. The client sends plain-text HTTP requests to the proxy over the LAN, and the proxy handles the encrypted communication.

Architecture

+---------------------+     HTTP (JSON, multi-turn)         +------------------+
|   AIChat Client     |  ????????????????????????????????????????????????????????????????????????????????????????????????   |  AIChatProxy     |
|   (Delphi 7)        |     {"messages":[...]}              |  (Python Flask)  |
|   Windows 95/NT     |     UTF-8 / token auth              |  LAN server      |
+---------------------+                                     +--------??????????????????????????????+
                                                                    ??? HTTPS
                                                                    ???
                                                         +------------------+
                                                         |   AI API         |
                                                         | (OpenAI, etc.)   |
                                                         +------------------+

The client keeps multi-turn history and sends the latest 200 messages (about 100 turns) as JSON ({"messages":[...]}). After validating the shared token, the proxy forwards them as a standard messages array and prepends a system prompt if configured.

Quick Start

Prerequisites

• Client: Delphi 7 IDE (to compile AIChat/AIChat.dpr)
• Proxy: Python 3.8+
• A machine on the same LAN to run the proxy (modern Windows, Linux or macOS)

1. Start the Proxy

cd AIChatProxy
cp .env.example .env
# Edit .env and set your API key
pip install -r requirements.txt
python proxy.py

Verify the proxy is running:

curl http://localhost:8080/ping    # health check
curl http://localhost:8080/status  # proxy config (no secrets)

2. Build the Client

Open AIChat/AIChat.dpr in the Delphi 7 IDE and compile with Ctrl+F9.

3. Configure the Client

Click Settings in the top-right corner after launching the client, then enter the proxy host, port and optional access token. Settings are stored in the registry under HKEY_CURRENT_USER\Software\AIChat9x, so no config file needs to be edited.

4. Run

Copy the compiled AIChat.exe to the target Windows 95/NT machine and run it.

Configuration

All proxy settings live in AIChatProxy/.env:

Project Structure

aichat9x/
????????? AIChat/                   # Delphi 7 client
???   ????????? AIChat.dpr            # Project entry point
???   ????????? AIChatMain.pas/.dfm   # Main form and logic
???   ????????? AIChatCtrls.pas       # Custom-drawn UI controls
???   ????????? AIChatHttp.pas        # WinInet HTTP client
???   ????????? AIChat.ico            # 16-colour retro icon
???   ????????? AIChat.res            # Icon resource (MAINICON)
???   ????????? AIChat.rc             # Icon resource script
???   ????????? AIChat.chat           # Chat history (runtime)
???   ????????? BIN/                  # Build output
???       ????????? AIChat.exe
????????? AIChatProxy/              # Python proxy
???   ????????? proxy.py              # Proxy server
???   ????????? requirements.txt      # Dependencies
???   ????????? .env.example          # Config template
???   ????????? .env                  # Runtime config (gitignored)
????????? .gitignore
????????? AGENTS.md
????????? README.md                 # This file (English)
????????? README.zh-CN.md           # Chinese documentation

Technical Constraints

• GDI limitation: The client only uses GDI functions from gdi32.dll and user32.dll; it does not depend on msimg32.dll (unavailable on Windows 95/NT).
• Multi-turn conversation: The client keeps full history in memory and sends the latest 200 messages (about 100 turns) as JSON. Chat history can be saved/loaded to a .chat file. Right-click the chat panel to copy one message or all of them.
• UI: Borderless purple self-drawn theme inspired by wenyinos.com, with a gradient title bar, custom window buttons, pill buttons, avatar chat cards, an empty-state hero and a 16-colour retro icon (16x16 + 32x32). The window is fixed at 760×600 with maximize/restore support. Enter sends, Shift+Enter inserts a newline; Ctrl+N clears, Ctrl+O loads, Ctrl+S saves, F5 tests the connection; right-click the chat area to copy one message or all.
• Encoding: Client and proxy exchange UTF-8 JSON; proxy and AI API exchange UTF-8 JSON. The proxy's plain-text compatibility endpoint uses GBK.
• Connection test: Client menu File → Test Connection verifies proxy reachability.
• File encoding: Delphi source files (.pas, .dfm, .dpr) must use CRLF line endings without BOM; files containing Chinese must be saved as GBK (CP936), never UTF-8.