decompile_assembly

Decompilation

The primary tool for reverse-engineering .NET binaries. Recovers full C# source code from compiled .dll or .exe files. Supports targeted decompilation of individual types, compilable project generation, IL output, PDB generation, and output truncation for large assemblies.

Parameters

Parameter	Type	Required	Default	Description
assembly_path	string	Yes	—	Path to the .dll or .exe file
output_dir	string|null	No	null	Directory to save decompiled files (returns inline if omitted)
type_name	string|null	No	null	Fully qualified type name to decompile a single type
language_version	string	No	"Latest"	C# syntax version: CSharp1—CSharp12_0, Preview, Latest
create_project	bool	No	false	Generate a compilable .csproj project structure
show_il_code	bool	No	false	Output IL bytecode instead of C#
remove_dead_code	bool	No	false	Strip unreachable code paths
remove_dead_stores	bool	No	false	Strip unused variable assignments
show_il_sequence_points	bool	No	false	Include debug sequence points in IL (implies show_il_code)
nested_directories	bool	No	false	Organize output in namespace-based directory hierarchy
generate_pdb	bool	No	false	Generate a portable PDB file (requires output_dir)
use_pdb_variable_names	bool	No	false	Use original variable names from an existing PDB
max_output_chars	int	No	100000	Max inline characters. Excess is saved to a temp file. 0 disables truncation

Example

MCP JSON

{
  "tool": "decompile_assembly",
  "arguments": {
    "assembly_path": "/path/to/MyApp.dll",
    "type_name": "MyApp.Services.AuthService",
    "language_version": "Latest"
  }
}

Python

result = await client.call_tool("decompile_assembly", {
    "assembly_path": "/path/to/MyApp.dll",
    "type_name": "MyApp.Services.AuthService",
    "language_version": "Latest",
})

Response

Returns decompiled C# source code (or IL bytecode) as formatted text. When output_dir is provided, files are written to disk and the response confirms the output path. If the output exceeds max_output_chars, the full result is saved to a temporary file and a truncated preview is returned with recovery instructions.

Usage tips

• Use type_name for targeted decompilation of specific classes instead of the entire assembly.
• Use create_project when you need compilable output with a .csproj file.
• generate_pdb and use_pdb_variable_names require output_dir to be set.
• If output is truncated, use decompile_method to extract individual methods.

Related tools

• decompile_method — extract a single method from a type
• list_types — discover type names before targeted decompilation
• get_assembly_info — quick reconnaissance before deep-diving