# Ilspy Decompile

> 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.

- **Type:** Skill
- **Install:** `agentstack add skill-aaronontheweb-dotnet-skills-ilspy-decompile`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [Aaronontheweb](https://agentstack.voostack.com/s/aaronontheweb)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [Aaronontheweb](https://github.com/Aaronontheweb)
- **Source:** https://github.com/Aaronontheweb/dotnet-skills/tree/master/skills/ilspy-decompile

## Install

```sh
agentstack add skill-aaronontheweb-dotnet-skills-ilspy-decompile
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# .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 with `ilspycmd -h`.

## Quick start

```bash
# 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

```bash
~/.nuget/packages///lib//
```

### .NET runtime libraries

```bash
dotnet --list-runtimes
```

### .NET SDK reference assemblies

```bash
dotnet --list-sdks
```

> Reference assemblies do not contain implementations.

### Project build output

```bash
./bin/Debug/net8.0/.dll
./bin/Release/net8.0/publish/.dll
```

## Core workflow

1. Identify what you want to understand
2. Locate the assembly
3. List types
4. Decompile the target

## Commands

### Basic decompilation

```bash
ilspycmd MyLibrary.dll
ilspycmd -o ./decompiled MyLibrary.dll
ilspycmd -p -o ./project MyLibrary.dll
```

### Targeted decompilation

```bash
ilspycmd -t Namespace.ClassName MyLibrary.dll
ilspycmd -lv CSharp12_0 MyLibrary.dll
```

### View IL code

```bash
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.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [Aaronontheweb](https://github.com/Aaronontheweb)
- **Source:** [Aaronontheweb/dotnet-skills](https://github.com/Aaronontheweb/dotnet-skills)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-aaronontheweb-dotnet-skills-ilspy-decompile
- Seller: https://agentstack.voostack.com/s/aaronontheweb
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.