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One Interface To Rule Them All

FluentStorage is a fully managed polycloud .NET cloud storage library, optimized for speed. It helps you interface with multiple cloud providers from a single unified API, allowing you to switch cloud providers or support multiple cloud providers without any logic changes.

It provides a single unified API for Object storage and Queue messaging across all cloud storage providers like AWS S3, AWS SQS, GCP Storage, FTP, FTPS, SFTP, Local Disk, Azure Blob, Azure Files, Azure Queue, Azure Service Bus, Azure Data Lake, Azure Key Vault, Cloudflare R2, DigitalOcean Spaces, MinIO, Wasabi, Backblaze B2, Hetzner, Vultr, MongoDB GridFS, Alibaba OSS. Each provider has its own Nuget package with zero configuration required.

It provides extensive Object manipulation commands, File uploads/downloads, File streaming/seeking, Unified path system, Object metadata, Object versioning, Object tags, Object storage tier/class, Presigned URL generation, Directory listing & Directory manipulation, File permissions/CHMOD and more.

Its API is fully asynchronous and has identical behavior across all providers. It also implements in-memory and local disk providers, so you can test on a local machine or access attached NAS/EBS drives.

It is written entirely in C#, with few external dependencies. No configuration files are required.

FluentStorage is released under the permissive MIT License, so it can be used in both proprietary and free/open source applications.

Storage Providers

FluentStorage supports the following cloud storage providers:

	Documentation Link	Factory class	Store class	GetClient() returns
	AWS S3	AwsS3Storage	S3Store	AmazonS3Client
	Azure Blobs	AzureBlobStore	AzureBlobStore	BlobServiceClient
	Azure Files	AzureFilesStorage	AzureFilesStore	ShareServiceClient
	Azure DataLake	AzureDataLakeStorage	AzureDataLakeStore	ExtendedSdk
	GCP	GoogleCloudStorage	GoogleCloudStore	StorageClient
	MinIO (native)	MinioStorage	MinioStore	MinioClient
	MinIO (S3)	MinioS3Storage	S3Store	AmazonS3Client
	Cloudflare R2	CloudflareR2Storage	S3Store	AmazonS3Client
	DigitalOcean Spaces	DigitalOceanSpacesStorage	S3Store	AmazonS3Client
	Wasabi	WasabiStorage	S3Store	AmazonS3Client
	Backblaze B2	BackblazeB2Storage	S3Store	AmazonS3Client
	Hetzner	HetznerStorage	S3Store	AmazonS3Client
	Vultr	VultrStorage	S3Store	AmazonS3Client
	MongoDB GridFS	MongoGridStorage	MongoGridStore	MongoClient
	Alibaba OSS	AlibabaStorage	AlibabaStore	OssClient
	FTP	FtpStorage	FtpStore	AsyncFtpClient
	SFTP	SftpStorage	SftpStore	SftpClient
	Local Disk	StorageFactory	DiskStore	IFileSystem

To add support for a new S3-compatible provider, search for [ADD STORAGE PROVIDER] across all code files.

Polycloud API

This table shows the API supported by IStore across various cloud and server providers.

API	Azure Blobs	Azure Files	AWS S3	GCP	MinIO	Mongo	Alibaba	FTP	SFTP	Disk
System information
GetClient	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
GetServer	❌	❌	❌	❌	❌	✔️	❌	✔️	✔️	✔️
File listing
ListDirectory	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
ListObjects	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
File upload/download
GetObject	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
SetObject	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
GetBytes	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
SetBytes	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
DownloadObject	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
UploadObject	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
OpenRead	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
OpenWrite	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
API	Azure Blobs	Azure Files	AWS S3	GCP	MinIO	Mongo	Alibaba	FTP	SFTP	Disk
File streaming/seeking
OpenRange	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
OpenSeekable	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
File manipulation
ObjectExists	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
MoveObject	✔️	❌	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
DeleteObject	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
DeleteObjects	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
File metadata
GetObjectLength	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
GetObjectInfo	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
GetObjectsInfo	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️
SetObjectInfo	✔️	✔️	✔️	✔️	✔️	✔️	✔️	❌	❌	✔️
SetObjectsInfo	✔️	✔️	✔️	✔️	✔️	✔️	✔️	❌	❌	✔️
API	Azure Blobs	Azure Files	AWS S3	GCP	MinIO	Mongo	Alibaba	FTP	SFTP	Disk
File versioning
IsVersioned	✔️	🚫	✔️	✔️	🚫	🚫	🚫	🚫	🚫	🚫
ListObjectVersions	✔️	🚫	✔️	✔️	🚫	🚫	🚫	🚫	🚫	🚫
GetObjectVersion	✔️	🚫	✔️	✔️	🚫	🚫	🚫	🚫	🚫	🚫
RestoreObjectVersion	✔️	🚫	✔️	✔️	🚫	🚫	🚫	🚫	🚫	🚫
DeleteObjectVersion	✔️	🚫	✔️	✔️	🚫	🚫	🚫	🚫	🚫	🚫
File tagging
IsTagged	✔️	🚫	✔️	✔️	✔️	🚫	✔️	🚫	🚫	🚫
GetObjectTags	✔️	🚫	✔️	✔️	✔️	🚫	✔️	🚫	🚫	🚫
SetObjectTags	✔️	🚫	✔️	✔️	✔️	🚫	✔️	🚫	🚫	🚫
DeleteObjectTags	✔️	🚫	✔️	✔️	✔️	🚫	✔️	🚫	🚫	🚫
File storage tier
IsTiered	✔️	🚫	✔️	✔️	✔️	🚫	🚫	🚫	🚫	🚫
GetObjectTier	✔️	🚫	✔️	✔️	✔️	🚫	🚫	🚫	🚫	🚫
SetObjectTier	✔️	🚫	✔️	✔️	✔️	🚫	🚫	🚫	🚫	🚫
API	Azure Blobs	Azure Files	AWS S3	GCP	MinIO	Mongo	Alibaba	FTP	SFTP	Disk
Presigned URL generation
GetUploadUrl	✔️	🚫	✔️	✔️	✔️	🚫	✔️	🚫	🚫	🚫
GetDownloadUrl	✔️	🚫	✔️	✔️	✔️	🚫	✔️	🚫	🚫	🚫
GetPresignedUrl	✔️	🚫	✔️	✔️	✔️	🚫	✔️	🚫	🚫	🚫
GetObjectSas	✔️	🚫	✔️	✔️	✔️	🚫	✔️	🚫	🚫	🚫
File permissions
GetFilePermissions	❌	❌	❌	❌	❌	❌	❌	✔️	✔️	❌
SetFilePermissions	❌	❌	❌	❌	❌	❌	❌	✔️	✔️	❌
Directory manipulation
DirectoryExists	❌	❌	❌	❌	❌	❌	❌	✔️	✔️	✔️
CreateDirectory	❌	❌	❌	❌	❌	❌	❌	✔️	✔️	✔️
DeleteDirectory	❌	❌	❌	✔️	✔️	✔️	✔️	✔️	✔️	✔️
MoveDirectory	❌	❌	❌	❌	❌	❌	❌	✔️	✔️	✔️

Provider API

This table shows the API supported by specific cloud providers:

Azure Blobs	Azure Data Lake	AWS S3
IAzureBlobStore	IAzureDataLakeStore	IS3Storage
AcquireLease BreakLease GetContainerPublicAccess SetContainerPublicAccess GetStorageSas GetContainerSas	ListFilesystems CreateFilesystem DeleteFilesystem GetAccessControl SetAccessControl	SetAcl

Packages

Stable binaries are released on NuGet, and contain everything you need to use Cloud Storage in your .NET app.

	Package	Latest Version	Downloads	Documentation
	FluentStorage			Standard
	FluentStorage.AWS			S3, SQS
	FluentStorage.GCP			GCP
	FluentStorage.Azure			---
	FluentStorage.Azure.Blobs			Blob
	FluentStorage.Azure.Files			File
	FluentStorage.Azure.ServiceBus			ServiceBus
	FluentStorage.Azure.KeyVault			KeyVault
	FluentStorage.Azure.Queues			Queue
	FluentStorage.Minio			Minio
	FluentStorage.Mongo			Mongo
	FluentStorage.Alibaba			Alibaba
	FluentStorage.FTP			FTP
	FluentStorage.SFTP			SFTP

Concept Mapping

This table shows the API and the provider-specific concept it maps to:

Concept	AWS S3	Azure Blob	GCP
Versioning API	Object Versions	Blob Versions	Object Generations
Tagging API	Object Tags	Blob Index Tags / Blob Tags	Custom Metadata
Metadata API	Object Metadata	Blob Metadata	Object Metadata
Storage Tier	Storage Class	Access Tier	Storage Class
Retention API	Object Lock Retention	Immutability Policy	Retention Policy
Locking API	Object Lock Configuration / Legal Hold	Legal Hold + Immutability Policy	Object Holds

Storage Tier Mapping

This table shows the FluentStorage StorageTier enum and the provider-specific tier it maps to:

Concept	AWS S3	Azure Blob	GCP
StorageTier.Standard	STANDARD	Hot	STANDARD
StorageTier.Intelligent	INTELLIGENT_TIERING	AutoTiering	AUTOCLASS
StorageTier.Nearline	STANDARD_IA	Cool	NEARLINE
StorageTier.Cold	GLACIER_IR	Cold	COLDLINE
StorageTier.Archive	GLACIER	Archive	ARCHIVE
StorageTier.DeepArchive	DEEP_ARCHIVE	Archive	ARCHIVE

Platform Support

FluentStorage works on .NET and .NET Standard/.NET Core.

Platform	Binaries Folder
.NET 7.0	net70
.NET 8.0	net80
.NET 9.0	net90
.NET Standard 2.0	netstandard2.0
.NET Standard 2.1	netstandard2.1

FluentStorage is also supported on these platforms: (via .NET Standard)

• Mono 4.6
• Xamarin.iOS 10.0
• Xamarin.Android 10.0
• Universal Windows Platform 10.0

Binaries for all platforms are built from a single Visual Studio Project. You will need the latest Visual Studio to build or contribute to FluentStorage.

Architecture

Without FluentStorage

Today, most cloud applications and services are developed against vendor-specific APIs like Amazon S3 API or Azure Blob API for cloud storage capabilities.

Using multiple vendor-specific APIs can increase your vendor lock-in, and makes your application more complex and harder to maintain. And sometimes these APIs may not offer all the functionality you need for your application. Polycloud also becomes very hard to implement.

With FluentStorage

What if we had a single, consistent API to deal with all types of cloud storage? That would solve these issues and bring more flexibility in switching cloud providers or cloud services.

Thus was born the idea for FluentStorage.

You can use a single, consistent API to interact with multiple cloud providers, where each provider is supported through its own special Nuget package.

Documentation

Check the Wiki.

What's New

In 2026, we added:

• Version 8 with a massive redesign of the entire API and behaviour
• MongoDB GridFS provider using native MongoDB Driver
• MinIO provider using native Minio SDK
• Alibaba OSS provider using native Aliyun SDK
• Cloudflare R2 provider using S3-compatible SDK
• Backblaze B2 provider using S3-compatible SDK
• Hetzner provider using S3-compatible SDK
• Vultr provider using S3-compatible SDK
• Azure.Identity support for Azure Files with token credential, client secret, and managed identity authentication.
• Wiki pages per provider
• Removed unused packages: Databricks, EventHub, DataLake Gen 1, ServiceFabric

In 2025, we added:

• Azure.Identity support for Azure Blobs with token credential, client secret, and managed identity authentication.

In 2024, we added:

• DigitalOcean Spaces provider
• MinIO provider
• Wasabi provider

In 2023, we added:

• SFTP provider SSH.NET added
• FTP provider FluentFTP updated to v44
• AWS Nuget bumped to latest versions
• Wiki created for documentation
• Platform support updated to netstandard2.0,netstandard2.1,net50,net60

Similar Libraries

• Foundatio - Caching, Messaging, Queues and Storage library with AWS, Azure and many other providers
• SlimMessageBus - Messaging library with providers like RabbitMQ, Kafka, Azure EventHub, MQTT, Redis
• ManagedCode.Storage - Storage library with AWS, Azure, GCP and other providers

Sponsorship

FluentStorage has received major sponsorship from these generous organizations:

Microsoft Corporation

Has FluentStorage made a difference for you or your organization? If so, consider becoming a sponsor to help keep the project thriving. Even a small monthly contribution, like $20, can make a meaningful impact.

Contributors

Special thanks to these awesome people who helped create FluentStorage!