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fantomas

v8.1.1Latest Stable
Any Framework

This library aims at formatting F# source files based on a given configuration. Fantomas will ensure correct indentation and consistent spacing between elements in the source files. Some common use cases include: (1) Reformatting a code base to conform a universal page width (2) Converting legacy code from verbose syntax to light syntax (3) Formatting auto-generated F# signatures.

Published
Nov 3, 2026
7d ago
Total Downloads
3.8M
3,778,633

Install

dotnet add package fantomas --version 8.1.1

No framework information available.

README

Fantomas

Fantomas logo

GitHub CI Status Discord Nuget (with prereleases) llms.txt llms-full.txt

An opinionated F# source code formatter.

dotnet tool install fantomas

Documentation is available at https://fsprojects.github.io/fantomas/docs/

If you point a coding agent at Fantomas, give it llms.txt for an index of the documentation, or llms-full.txt for all of it in one file.

Reporting a bug

Report bugs through the online tool, which opens an issue with everything needed to reproduce it.

With a coding agent, the fantomas-report skill shrinks the file Fantomas failed on to a minimal sample and opens the same issue form for you to review:

npx skills add fsprojects/fantomas --skill fantomas-report -g

See Reporting a bug for more.

Contributing Guidelines

See the Contribution Guidelines and our contributors documentation

Changes from Previous Version

No structural changes between v8.1.0 and v8.1.1.

Adoption Assessment

A verified publisher signal is available. Assess fit from the package's supported frameworks, license and dependency graph rather than popularity alone.

No target framework metadata is available. Confirm compatibility in a representative project before standardising on this package.

Related Guides & Workflows

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