---
name: aspectgenerator
description: Configure and use AspectGenerator compile-time C# method aspects including hooks and lifetimes, target filters, shared aspect libraries, diagnostics and build troubleshooting when a project uses the AspectGenerator NuGet package.
---

# AspectGenerator

AspectGenerator provides AOP-like compile-time method aspects for C# by rewriting visible call sites with C# interceptors. It is not runtime AOP, does not use runtime proxies, and does not weave IL.

Build consuming projects with .NET SDK 9.0.100 or later (Roslyn 4.12), which Visual Studio 2022 has shipped since version 17.12 (November 2024). An older compiler reports `CS9057` and does not load the generator, so aspects are not applied. This is a build-toolchain requirement; a `net8.0` project built with that SDK works.

Use `<PackageReference Include="AspectGenerator" PrivateAssets="all" />` for a private build-time dependency, with `Version` set to the version of the AspectGenerator package this skill ships in. Each project compiling call sites to intercept needs the generator, normally through a direct reference. A library can explicitly pass it and its MSBuild wiring to consumers with `PrivateAssets="none"`. The package has no runtime assembly.

The skill is available at `<global-packages>/aspectgenerator/<version>/skills/aspectgenerator/` or as a copy in `.agents/skills/aspectgenerator/` or `.claude/skills/aspectgenerator/`. Its guides use relative links and work in either location.

## Guide index

- [Writing an aspect](docs/writing-an-aspect.md) — static hooks, lifecycle, conditional aspects and instance lifetimes.
- [Target filters](docs/target-filters.md) — assembly/type applications, ordered rules and canonical signatures.
- [Diagnostics and fixes](docs/diagnostics.md) — AGxxxx diagnostics and optional AG0300 markers.
- [Library mode and PrivateAssets](docs/library-mode.md) — package references and generated API ownership across projects.
- [Configuration](docs/configuration.md) — MSBuild properties and assembly-level overrides.
- [Generator hosts and Hot Reload](docs/generator-host.md) — build versus design-time behavior and editor diagnostics.
- [Troubleshooting](docs/troubleshooting.md) — missing interception, supported targets, build reports, trace and review checks.