Building a tiny Windows tray app with .NET 9 Native AOT and raw Win32

I built CreditMeter, a small Windows tray app that shows GitHub Copilot AI-credit usage like a taxi meter.

Why I built it

Agentic coding makes AI usage feel invisible until you look at the bill.

Constraints

• no WinForms
• no WPF
• no backend
• no telemetry
• no dependency-heavy architecture

Tech stack

• C# / .NET 9
• Native AOT
• raw Win32 / PInvoke
• GitHub REST API
• DPAPI for local PAT storage

What I learned

For tiny tools, architecture is also about knowing what not to add.

Repo

https://github.com/cdilorenzo/CreditMeter