Build a Safe Repository Maintenance Agent with GitHub Copilot and Microsoft Agent Framework in .NET

This article provides a hands-on tutorial for building a .NET 10 console application that combines GitHub Copilot's coding harness with Microsoft Agent Framework to create a safe repository maintenance agent. The agent inspects a small repository, repairs a failing test, asks for permission before modifying files or running tests, and produces a maintenance report. It avoids network access, package installation, commits, and pull requests. The tutorial includes a disposable fixture with a deliberately broken test, prerequisites, and pinned package versions due to the preview status of the Copilot SDK. It's a continuation of a previous article on AI-assisted dependency vulnerability fixing, focusing on execution boundaries and safe agent behavior.