Introduction

What is ImageSharp.Web?

ImageSharp.Web is a high performance ASP.NET 6 Middleware built on top of ImageSharp that allows the processing and caching of image requests via a simple API.

ImageSharp.Web is designed from the ground up to be flexible and extensible. The library provides API endpoints for common image processing operations and the building blocks to allow for the development of additional extensions to add image sources, caching mechanisms or even your own processing API.

License

ImageSharp.Web is licensed under the terms of the Six Labors Split License, Version 1.0. See https://sixlabors.com/pricing for commercial licensing details.

Important

Starting with ImageSharp.Web 3.3.0, projects that directly reference this package require a valid Six Labors license key at build time. Enforcement applies to direct dependencies only. This is enforcement of the existing license terms, not a license change.

Installation

ImageSharp.Web is installed via NuGet with nightly builds available on MyGet.

PM > Install-Package SixLabors.ImageSharp.Web -Version VERSION_NUMBER
Warning

Prerelease versions installed via the Visual Studio NuGet Package Manager require the "include prerelease" checkbox to be checked.

Implicit Usings

The UseImageSharp property controls whether implicit global using directives for ImageSharp are included in your C# project. This feature is available in projects targeting .NET 6 or later with C# 10 or later.

When enabled, a predefined set of global using directives for common ImageSharp namespaces (such as SixLabors.ImageSharp, SixLabors.ImageSharp.Processing, SixLabors.ImageSharp.Web etc.) is automatically added to the compilation. This eliminates the need to manually add using statements in every file.

To enable implicit ImageSharp usings, set the property in your project file:

<PropertyGroup>
  <UseImageSharp>true</UseImageSharp>
</PropertyGroup>

To disable the feature, either remove the property or set it to false:

<PropertyGroup>
  <UseImageSharp>false</UseImageSharp>
</PropertyGroup>

How to use the license file

By default, the build searches from each project directory for sixlabors.lic. Place the supplied file in the directory that contains the project file, or in a subdirectory below it. Use the file as supplied; it contains the complete license string required by the build.

Important

Assembly-scoped community keys can be committed to a public repository. Contributors can use the included key to build the named assemblies without obtaining their own keys. Unrestricted community keys and commercial keys must remain private. Use environment variables or repository secrets for those keys.

To keep the file elsewhere, including a repository root above the project directory, set SixLaborsLicenseFile in your project file or a shared props file:

<PropertyGroup>
  <!-- Set the location of the supplied license file. -->
  <SixLaborsLicenseFile>path/to/sixlabors.lic</SixLaborsLicenseFile>
</PropertyGroup>

To use an environment variable instead, set this project property:

<PropertyGroup>
  <!-- Read the complete license string from the environment. -->
  <SixLaborsLicenseKey>$(SIXLABORS_LICENSE_KEY)</SixLaborsLicenseKey>
</PropertyGroup>

Set SIXLABORS_LICENSE_KEY to the complete contents of your issued license, not only its Key field. Use the original value without escaping. Replace the entire example value below with your issued license contents.

PowerShell:

# Quotes preserve the field separators and the pipe between assembly signatures.
$env:SIXLABORS_LICENSE_KEY = 'Id=<id>;Kind=Community;ExpiryDateUtc=<expiry>;Key=Assembly:<signature>|<signature>'
dotnet build
dotnet publish

Bash:

# Quotes preserve the field separators and the pipe between assembly signatures.
export SIXLABORS_LICENSE_KEY='Id=<id>;Kind=Community;ExpiryDateUtc=<expiry>;Key=Assembly:<signature>|<signature>'
dotnet build
dotnet publish

If you pass the license directly through -p:SixLaborsLicenseKey, escape every semicolon as %253B. MSBuild treats semicolons as property separators even inside a quoted argument. The pipe between assembly signatures stays unchanged.

PowerShell:

# Escape field separators only when passing the license through -p:.
dotnet build "-p:SixLaborsLicenseKey=$($env:SIXLABORS_LICENSE_KEY.Replace(';', '%253B'))"
dotnet publish "-p:SixLaborsLicenseKey=$($env:SIXLABORS_LICENSE_KEY.Replace(';', '%253B'))"

Bash:

# Escape field separators only when passing the license through -p:.
dotnet build "-p:SixLaborsLicenseKey=${SIXLABORS_LICENSE_KEY//;/%253B}"
dotnet publish "-p:SixLaborsLicenseKey=${SIXLABORS_LICENSE_KEY//;/%253B}"

You do not need to reference the licensing package directly. Projects that directly reference a Six Labors package carry its build-time validation.

Community keys for public projects

For an open-source or source-available application, provide the exact AssemblyName of every project that directly references a Six Labors package, including test projects. Names are case-sensitive.

For example, if MyProject.csproj sets <AssemblyName>MyProject.Core</AssemblyName>, enter MyProject.Core. If it does not set AssemblyName, enter MyProject, the project filename without .csproj. If a shared props file sets the name, use that value. Do not include .dll or .csproj.

Existing community license holders can request one early replacement with an assembly-scoped key. These upgrade requests are approved automatically, without another eligibility review. You do not need to wait for your current key to enter its renewal window.

Apply at licensing.sixlabors.com. Select open-source or source-available, use the same email address, and provide the assembly names. Later requests follow the normal renewal window: the final 90 days before the expiry date in your license. Commercial licenses are not eligible for this early replacement.

Security support

The latest major version of each library is eligible for security updates. Each major remains eligible for 12 months after the first stable release of its successor. A later major release does not shorten an existing support window.

Install the latest available patch or minor release within a supported major to receive security fixes. Older releases within that major are not maintained separately. This policy covers security fixes only. It does not include feature backports or extend Microsoft's support for the underlying .NET version. Security fixes remain at Six Labors' discretion.