FulcrumFS

FulcrumFS is a high-performance file processing pipeline and storage engine that layers on top of any file system, transforming standard directories into transactional file repositories with database-aligned commit semantics and file variant management.

While it serves as a key component of the upcoming FulcrumDB database engine, it is also designed to function independently, bringing robust file handling to any application or database. FulcrumFS is especially well-suited for managing user-uploaded content such as documents, images and videos, offering strong guarantees around consistency and integrity.

When your application commits its database transaction before the repository transaction, FulcrumFS guarantees that:

  • Every file the database references is accessible in the repository, even after a crash.
  • Every file the database no longer references is eventually deleted, so storage never leaks.

See the Transactional Commit Model for how these guarantees are achieved without distributed transactions.

FulcrumFS is part of the Singulink Libraries collection. Visit https://github.com/Singulink/ to see our full list of publicly available libraries and other open-source projects.

Installation

The libraries are available on NuGet. Install the packages that match your needs:

  • Singulink.FulcrumFS - the main transactional storage and processing engine.
  • Singulink.FulcrumFS.Core - the lightweight FileId, repository paths, and FileFormat validation API (usable standalone, including in client apps).
  • Singulink.FulcrumFS.Images - image processing pipeline steps (powered by ImageSharp).
  • Singulink.FulcrumFS.Videos - video processing pipeline steps (powered by FFmpeg / FFprobe).

Supported Runtimes: .NET 10.0+

Here are some additional links to get you started:

  • Getting Started - Visit here first for a quick walkthrough and entry point to additional guides.
  • Guides - In-depth articles on every aspect of the libraries.
  • Concepts - How the repository, pipelines, variants and crash recovery work under the hood.
  • API Documentation - Browse the fully documented API here.
  • Chat on Discord - Have questions or want to discuss the library? This is the place for all Singulink project discussions.
  • Github Repo - File issues, contribute pull requests or check out the code for yourself!