Quickstart

This walks you from an installed tool to a fused payload you can read. If you have not installed Fuse yet, see Install.

Run one command

Point Fuse at a .NET source directory:

fuse dotnet --directory ./src

The dotnet command selects the file extensions and exclusions appropriate for a .NET solution (C#, project files, Razor, configuration) and applies C# reduction.

Read what it prints

When the run finishes, Fuse reports the shape of the result:

Fused 511 files
Estimated tokens: 420,320 (-9.8%)
cache: 0 hit / 511 miss
Output: AutoMapper_2026-06-20_0130_420k.txt

It tells you the number of files included, the estimated token count and how much that cut from raw concatenation, the reduction cache split as cache: N hit / M miss, and where the file was written. By default the output goes to a Fuse folder inside your Documents directory, and the file name ends with a token estimate such as 420k.

Look inside the output

The file opens with a manifest: a header that lists every included file with its token cost, so a reader or an agent can judge the shape and cost of the fusion before reading any file body. After the manifest, each file appears as an entry. In the default XML format an entry looks like this:

<file path="src/Services/OrderService.cs">
public class OrderService { }
</file>

Files are ordered largest first by token count, so the most expensive content is at the top.

Choose how much to reduce

The default run does light, lossless cleanup. To cut more while keeping the public API, add --all:

fuse dotnet --directory ./src --all

For an architecture-level survey, drop method bodies to signatures with a skeleton, which typically runs 66 to 93 percent smaller than a full fusion:

fuse dotnet --directory ./src --all --skeleton

The Reduction levels concept page explains each step, and Cut tokens for .NET is the task-shaped version of this.

Control the output

Name the file and choose where it lands:

fuse dotnet --directory ./src --output ./context --name myproject

Set project defaults

To avoid repeating flags, write a configuration file once:

fuse init

This scaffolds a fuse.json you can edit. See Configuration keys for every supported key.

Next

Hand the output to an agent automatically with the MCP server, or learn the model behind a run in How Fuse works.