ilspy-decompile

1# .NET Assembly Decompilation with ILSpy
2 
3Use this skill to understand how .NET code works internally by decompiling compiled assemblies.
4 
5## Prerequisites
6 
7- .NET SDK installed
8- ILSpy command-line tool available via one of the following:
9  - `dnx ilspycmd` (if available in your SDK or runtime)
10  - `dotnet tool install --global ilspycmd`
11 
12Both forms are shown below. Use the one that works in your environment.
13 
14> Note: ILSpyCmd options may vary slightly by version.  
15> Always verify supported flags with `ilspycmd -h`.
16 
17## Quick start
18 
19```bash
20# Decompile an assembly to stdout
21ilspycmd MyLibrary.dll
22# or
23dnx ilspycmd MyLibrary.dll
24 
25# Decompile to an output folder
26ilspycmd -o output-folder MyLibrary.dll
27```
28 
29## Common .NET Assembly Locations
30 
31### NuGet packages
32 
33```bash
34~/.nuget/packages/<package-name>/<version>/lib/<tfm>/
35```
36 
37### .NET runtime libraries
38 
39```bash
40dotnet --list-runtimes
41```
42 
43### .NET SDK reference assemblies
44 
45```bash
46dotnet --list-sdks
47```
48 
49> Reference assemblies do not contain implementations.
50 
51### Project build output
52 
53```bash
54./bin/Debug/net8.0/<AssemblyName>.dll
55./bin/Release/net8.0/publish/<AssemblyName>.dll
56```
57 
58## Core workflow
59 
601. Identify what you want to understand
612. Locate the assembly
623. List types
634. Decompile the target
64 
65## Commands
66 
67### Basic decompilation
68 
69```bash
70ilspycmd MyLibrary.dll
71ilspycmd -o ./decompiled MyLibrary.dll
72ilspycmd -p -o ./project MyLibrary.dll
73```
74 
75### Targeted decompilation
76 
77```bash
78…