CBFS Connect
The leading SDK for creating and managing virtual filesystems from almost any type of storage.
DownloadHighlights include support for Docker Containers, a new cross-platform FUSE component, a new cache component for efficient remote file caching, and a host of core performance and usability improvements [learn more].

Create and Manage Virtual Filesystems
CBFS Connect allows you to present any data source as a fully-featured filesystem - be it local or remote files, dynamically-generated content, cloud storage, database records, or anything in-between. Without writing a single line of driver code, you will be able to expose your data as just another drive with folders and files, making it easy for users to view and interact with, and giving other applications the ability to access and manipulate it via standard file APIs.
Kernel programming is hard, and as Apple states in its macOS documentation pages, it should be avoided if at all possible. CBFS Connect provides a safer and more flexible approach to kernel development, allowing for improved security and stability while still offering the benefits of kernel-level access to the file system. With over 20 years of experience and trusted by hundreds of leading technology companies, we understand the kernel so you don't have to.
CBFS Connect acts as an intermediary between the file system and user mode code, and instead of executing code directly in the kernel, Connect proxies filesystem actions into callback events. You implement handlers for these events, which execute in a separate process.
By isolating the user mode code from the kernel, CBFS Connect reduces the risk of security vulnerabilities that could be exploited by attackers. In addition, because the user mode code is not executing code directly in the kernel, it is less likely to cause system crashes or other stability issues.
A virtual filesystem created with CBFS Connect has many advantages over filesystem-like and partial feature implementations. With capabilities similar to NTFS, virtual filesystems enable file locking and partial file updates. Easily enable transparent encryption and file access auditing by implementing the read/write events. Large files are available in blocks for efficient copy/move, or for streaming without having to download an entire file first. CBFS Connect is low-overhead, so applications using it can remain always connected or started/stopped like removable storage.
Comprehensive Features for Maximum Flexibility
Tested And Proven
The development of CBFS Connect is backed by decades of kernel experience, and the product is rigorously tested with hundreds of our internal tests as well as the tests developed by Microsoft for filesystem implementations. Callback Technologies components are trusted by leading technology companies around the world.
Create Robust Filesystem Implementations
CBFS Connect's performant, event-driven architecture allows your application to manage every aspect of your virtual filesystem's operation. You will quickly get from "idea" to "implementated" thanks to its consistent API and extensive documentation.
Leverage Any Data Source
You have full control over the contents of your virtual filesystem, so you can use any data source your application has access to. It can be local or remote, a database or REST service, static or dynamically-generated, or something else entirely.
Docker Container Support
Create virtual drives within Docker containers. The driver is installed exclusively on the host and does not need to be part of the container initialization.
Enforce Custom Access Restrictions
Only your application knows the real location of your data, so you can create and enforce your own permission schemas specifying which users and third-party applications can access, view, or modify it.
Simple Deployment
Simplified deployment through a single CAB file which contains everything required for for driver installation on Windows.
Advanced Functionality
Support for many advanced features including named streams, directory change notifications, reparse points, fsctl requests, hard links, quotas, file IDs, short file names, Plug-n-Play, custom disk icons, and more!
Flexible Mounting Options
Includes support for network mounting points, session-local mounting points, and UNC paths. Mount disks as fixed or removable. Multiple mounting points per disk are supported.
Granular Control
Fine grained user access control supports advanced security requirements. Optimize for specific implementations with per-file and per-handle context objects, and in-memory or disk caching options.
Utilize NTFS Security Features
CBFS Connect supports all standard NTFS security mechanisms, allowing you to easily secure the contents of your virtual filesystem.
FUSE-Like Cross Platform Support
The cross-platform FUSE component brings a FUSE-like API to all supported platforms, which makes writing virtual filesystem apps for multiple OSs consistent and simple.
Modify Remote Data On-the-Fly
Easily handle use-cases that require on-the-fly modification of remote data, such as client-side encryption. All operations take place within the virtual filesystem and are completely transparent to end-users.
Designed For Stability and Security
CBFS Connect separates your code from the kernel, thereby increasing system stability and security should exceptions arise.
Supported Platforms
.NET
Managed .NET Components
Managed .NET components based on the same high-performance codebase as our native editions. The edition of choice for managed .NET applications.
Cross-platform support for Windows, Linux, macOS and anywhere .NET Standard is supported.
Native libraries are also available for individual platforms.
- Managed .NET components built atop our high-performance shared codebase.
- Extensive demo applications written in C#.
- Comprehensive integrated product documentation.
- Seamless integration with Visual Studio.
- Support for .NET Framework up to 4.8.
- Supports Windows Vista / Server 2008 and later, Linux and macOS.
- Support for .NET 6, .NET 5, .NET Core 3.1, and earlier.
C++
High-Performance C++ Classes
High-performance C++ classes packaged in 32-bit & 64-bit Windows DLLs; and C++ libraries that can be compiled against Linux, macOS, FreeBSD, and more. The edition of choice for C++ development on any platform.
- C++ classes built atop our high-performance shared codebase.
- Extensive C++ demo applications.
- Comprehensive HTML product documentation.
- Seamless integration with popular development environments, including Visual Studio.
- Supports Windows Vista / Server 2008 and later; plus Linux (kernel 2.6.x+) and macOS.
Delphi
Native Delphi Components
Native Delphi components with no external dependencies, based on the same high-performance codebase as our other editions. The natural choice for Delphi programming.
- Delphi VCL components built atop our high-performance shared codebase.
- Extensive Delphi demo applications.
- Comprehensive integrated product documentation.
- Support for all Delphi versions between Delphi 6 and RAD Studio 11.
- Supports Windows Vista / Server 2008 and later.
Java
Powerful Java Classes
Powerful Java Classes, based on the same high-performance codebase as our native editions. The edition of choice for cross-platform Java development.
- Java Classes built atop our high-performance shared codebase.
- Extensive demo applications written in Java.
- Includes comprehensive JavaDocs.
- Seamless integration with popular development environments, including IntelliJ and Eclipse.
- Supports Java 1.5+.
- Supports Windows Vista / Server 2008 and later; plus Linux (kernel 2.6.x+) and macOS.
Python
Python Modules
Python modules for Windows, Linux, and macOS; featuring the same trustworthy components that come with other editions, available for use in Python 3.
- Python modules for Windows, Linux, and macOS.
- Support for Python 3.
- Extensive console demo applications.
- Easy installation using PIP.
- Demo applications and comprehensive HTML documentation.
Qt
Qt Class Libraries
High-performance Qt classes packaged in 32-bit & 64-bit Windows DLLs; and C++ libraries that can be compiled against Linux, macOS, FreeBSD, and more. The edition of choice for Qt development on any platform.
- 32-bit & 64-bit C++ class libraries (Windows DLLs).
- C++ Libraries for Unix (Linux, FreeBSD, etc.).
- Support for Qt 4.8 and Qt 5.
- Qt GUI demo applications and comprehensive HTML documentation
- Seamless integration with Qt Creator.
- Supports Windows Vista / Server 2008 and later; plus Linux (kernel 2.6.x+).
Go
Go Packages
High-performance Go packages based on the same C++ codebase as our other editions. The edition of choice for Go development on any platform.
- High-performance, C++-based Go modules.
- 32-bit & 64-bit C++ class libraries (Windows DLLs).
- Supports Go 1.13 and later.
- Comprehensive HTML product documentation.
- Supports Windows Vista / Server 2008 and later; plus Linux (kernel 2.6.x+).
Included Demos
The following demos are installed with the product. Please Download the trial to get started.
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CBFS Connect
The leading SDK for creating and managing virtual filesystems from almost any type of storage.