AarononthewebInstall Ilspy Decompile
Pick your agent. Every command is ready to paste.
npx skills add Aaronontheweb/dotnet-skills --skill ilspy-decompileThe open skills CLI detects your agents (Claude Code, Cursor, Codex and 70+ more) and installs to the right folder. Add -g to install globally.
01
Install it
Run the command above, or upload the folder in Claude.
02
Ask naturally
Describe the task. Your agent loads ilspy-decompile when the request matches its description.
03
Name it if needed
If it does not trigger, say “use the ilspy-decompile skill”. In Codex, type $ilspy-decompile.
.NET Assembly Decompilation with ILSpy
Use this skill to understand how .NET code works internally by decompiling compiled assemblies.
Prerequisites
- .NET SDK installed
- ILSpy command-line tool available via one of the following:
dnx ilspycmd(if available in your SDK or runtime)dotnet tool install --global ilspycmd
Both forms are shown below. Use the one that works in your environment.
Note: ILSpyCmd options may vary slightly by version.
Always verify supported flags withilspycmd -h.
Quick start
# Decompile an assembly to stdout
ilspycmd MyLibrary.dll
# or
dnx ilspycmd MyLibrary.dll
# Decompile to an output folder
ilspycmd -o output-folder MyLibrary.dll
Common .NET Assembly Locations
NuGet packages
~/.nuget/packages/<package-name>/<version>/lib/<tfm>/
.NET runtime libraries
dotnet --list-runtimes
.NET SDK reference assemblies
dotnet --list-sdks
Reference assemblies do not contain implementations.
Project build output
./bin/Debug/net8.0/<AssemblyName>.dll
./bin/Release/net8.0/publish/<AssemblyName>.dll
Core workflow
- Identify what you want to understand
- Locate the assembly
- List types
- Decompile the target
Commands
Basic decompilation
ilspycmd MyLibrary.dll
ilspycmd -o ./decompiled MyLibrary.dll
ilspycmd -p -o ./project MyLibrary.dll
Targeted decompilation
ilspycmd -t Namespace.ClassName MyLibrary.dll
ilspycmd -lv CSharp12_0 MyLibrary.dll
View IL code
ilspycmd -il MyLibrary.dll
Notes on modern .NET builds
- ReadyToRun images may reduce readability
- Trimmed or AOT builds may omit code
- Prefer non-trimmed builds
Legal note
Decompiling assemblies may be subject to license restrictions.
Tips for Ilspy Decompile
- • Start a fresh session after installing so your agent picks up the new skill.
- • It is part of a pack with 30 skills. Install only the ones you need with --skill to keep triggers precise.
- • If two skills overlap, mention the one you want by name.
Questions about Ilspy Decompile
What does the Ilspy Decompile skill do?
Understand implementation details of .NET code by decompiling assemblies. Use when you want to see how a .NET API works internally, inspect NuGet package source, view framework implementation, or understand compiled .NET binaries.
How do I install Ilspy Decompile?
Run "npx skills add Aaronontheweb/dotnet-skills --skill ilspy-decompile" in your project. The skills CLI installs it for Claude Code, Cursor, Codex and 70+ other agents. In Claude on the web, upload the skill folder as a ZIP under Customize > Skills.
Does Ilspy Decompile work in Cursor and Codex?
Yes. Ilspy Decompile uses the open SKILL.md format, so it works in Claude Code, Claude, Cursor, OpenAI Codex, Gemini CLI, GitHub Copilot and other agents that support agent skills.
Is Ilspy Decompile free?
Ilspy Decompile is open source on GitHub under the MIT license. It is free to install; check the license before commercial use.
Who made Ilspy Decompile?
Ilspy Decompile is published by Aaronontheweb in the Aaronontheweb/dotnet-skills repository, together with 29 other skills.
