FSharp.Refactor MCP server

FSharp.Refactor

Let's remove parentheses from the internet

Functional refactoring suggestions for F#. The tool clarifies the (agent-generated or old) code's intent, reduces non-alphanumeric noise, and uses built-in .NET libraries more efficiently.

• light bulb quick fixes in your editor
• command-line tool that applies them in bulk.

Suggestions are Hint severity: they mark an opportunity, not a defect, and never gate your build.

This project is the big brother of CSharp.Refactor

Using it

The tool is fully offline: AI has been used to make it, but it doesn't use AI.

Quick start

Nothing to configure - the tool reads your project, reports what it would change, and only edits when you tell it to:

dotnet tool install --global fsharp-refactor
fsharp-refactor Your.fsproj --dry-run --api-changes

That prints every fix it would make, with file and position, and writes nothing. When the list looks right, drop the flag to apply them:

fsharp-refactor Your.fsproj --api-changes

It refuses a compilation that does not already build, and fails loudly if applying ever introduces an error.

If you don't want change public methods / API, drop --api-changes:

fsharp-refactor Your.fsproj

For light bulbs while you type, see VS Code / Ionide and Visual Studio IDE-plugin instructions below.

For agentic scenarios the dotnet tool supports MCP.

Using the tool: Point it at whatever you have - the kind is read off the path:

What it changes

Examples:

A spread of what the 150-odd rules do - the full list is in Refactorings:

Editor and CI setup

The analyzers ship as FSharp.Refactor.Analyzers. The package is a development dependency: it only produces hints and quick fixes - nothing from it flows into your compiled output.

NOTE: EVEN WHEN ADDING A NUGET REFERENCE, THIS ANALYSER WILL NOT COME TO OUTPUT PATH (BIN) AND WILL NOT BE PART OF YOUR PROJECT.

VS Code / Ionide

Easiest: install the FSharp.Refactor VS Code extension

Ionide's settings globally, so every F# project gets the hints with no per-project setup.

• it bundles the analyzers and (with your consent) wires them into

Or wire a single project by hand: reference the package from the project you want analyzed:

<PackageReference Include="FSharp.Refactor.Analyzers" Version="*" PrivateAssets="all" />

then point Ionide at the restored analyzers in .vscode/settings.json:

Shortened. The full README is on GitHub.