A ChatGPT client for every screen, including Microsoft Office

What it does

It’s a C# ChatGPT client built on Avalonia UI, so the same codebase runs on desktop, mobile, and browser via WASM. You can chat, import backups from the official ChatGPT web app, and tweak the usual OpenAI parameters. The project also ships a .NET CLI tool for batch-processing files—think code conversion and documentation generation—and a COM interop layer that lets you call the API from Microsoft Office VBA macros.

The interesting bit

The COM interop support is the real curveball: the README includes full VBA examples for Word 2010, letting you translate selected text or build chat forms inside Office apps. That’s a level of legacy integration you don’t see in most modern API clients.

Key highlights

• Single Avalonia UI codebase targets macOS, Windows, Linux, Android, iOS, and browser WASM
• Live browser demo hosted on GitHub Pages
• Batch CLI tool supports directory-wide file processing with custom system prompts
• Can import conversation backups from the official ChatGPT web interface
• COM interop package exposes the client to VBA macros in Microsoft Office

Caveats

• README still pins the CLI tool to a 1.0.0-preview.17 release
• COM setup docs contain typos (regasmm.exe, “Microsoft Work 2010”) that suggest limited maintenance attention
• Requires an OpenAI API key; no local or offline model support is indicated

Verdict

.NET developers who want a truly cross-platform ChatGPT UI—or need to wire AI into legacy Office workflows—should look here. If you want local LLM inference or a polished mobile app store experience, this isn’t it.