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51Degrees Pipeline API

51Degrees Pipeline API

Developer Documentation

NuGet Package NuGet Package
NuGet CloudRequestEngine NuGet Examples.Shared
NuGet Core NuGet JavaScriptBuilder
NuGet Engines NuGet JsonBuilder
NuGet Engines.FiftyOne NuGet Web
NuGet Engines.TestHelpers NuGet Web.Shared


This repository contains all the projects required to build the .NET implementation of the Pipeline API. Individual engines (For example, device detection) are in separate repositories.

The specification is also available on GitHub and is recommended reading if you wish to understand the concepts and design of this API.


Visual Studio 2022 or later is recommended. Although Visual Studio Code can be used for working with most of the projects.

The Pipeline projects are written in C# and target .NET Standard 2.0.3 The Web integration multi-targets the following: - .NET Core 3.1 - .NET Core 6.0 - .NET Framework 4.6.2

The tested versions page shows the .NET versions that we currently test against. The software may run fine against other versions, but additional caution should be applied.

Solutions and projects

  • FiftyOne.Pipeline - The core projects that comprise the Pipeline API.
    • FiftyOne.Pipeline.Core - The core Pipeline classes such as Pipeline, FlowData, FlowElement and Evidence.
    • FiftyOne.Pipeline.Engines - Functionality for AspectEngines, a specialized FlowElement with additional features.
    • FiftyOne.Pipeline.Engines.FiftyOne - Functionality that is specific to 51Degrees aspect engines.
  • FiftyOne.Pipeline.Web - Projects that are relevant to the Pipeline API ASP.NET integration.
    • FiftyOne.Pipeline.Web - ASP.NET Core integration.
    • FiftyOne.Pipeline.Web.Framework - ASP.NET Framework integration.
    • FiftyOne.Pipeline.Web.Minify - FlowElement which takes the JavaScript function from the JavaScriptBundler element and minifies it.
    • FiftyOne.Pipeline.Web.Shared - Shared code that is used by both Core and Framework ASP.NET integrations.
  • FiftyOne.Pipeline.Elements - Projects for various common Flow Elements that are used by multiple other solutions.
    • FiftyOne.Pipeline.JavaScriptBuilder - An element that packages values from all 'JavaScript' properties from all engines into a single JavaScript function.
    • FiftyOne.Pipeline.JsonBuilder - An element that serializes all properties from all engines into JSON format.
  • FiftyOne.CloudRequestEngine - Projects related to making general requests to the 51Degrees cloud.
    • FiftyOne.Pipeline.CloudRequestEngine - An engine that makes requests to the 51Degrees cloud service.


You can either clone this repository and reference the projects locally or you can reference the NuGet packages directly.

Install-Package FiftyOne.Pipeline.Core
Install-Package FiftyOne.Pipeline.Engines
Install-Package FiftyOne.Pipeline.Engines.FiftyOne
Install-Package FiftyOne.Pipeline.Web
Install-Package FiftyOne.Pipeline.Web.Minify
Install-Package FiftyOne.Pipeline.JsonBuilder
Install-Package FiftyOne.Pipeline.JavaScriptBuilder
Install-Package FiftyOne.Pipeline.CloudRequestEngine

Note that the packages have dependencies on each other so you'll never need to install all of them individually. For example, Installing FiftyOne.Pipeline.Engines.FiftyOne will automatically add FiftyOne.Pipeline.Engines and FiftyOne.Pipeline.Core.


Pipeline Examples

There are several examples available that demonstrate how to make use of the Pipeline API in isolation. These are described in the table below. If you want examples that demonstrate how to use 51Degrees products such as device detection, then these are available in the corresponding repository and on our website.

Example Description
CustomFlowElement\1. Simple Flow Element Shows how to create a custom flow element that returns star sign based on a supplied date of birth.
CustomFlowElement\2. On Premise Engine Shows how to modify SimpleFlowElement to make use of the 'engine' functionality and use a custom data file to map dates to star signs rather than relying on hard coded data.
CustomFlowElement\3. Client-side evidence Shows how to modify SimpleFlowElement to request the data of birth from the user using client-side JavaScript.
CustomFlowElement\4. Cloud Engine Shows how to modify SimpleFlowElement to perform the star sign lookup via a cloud service rather than locally.
ResultCaching Shows how the result caching feature works.
UsageSharing Shows how to share usage with 51Degrees. This helps us to keep our products up to date and accurate.


  • FiftyOne.Pipeline.CloudRequestEngine.Tests - Tests for the CloudRequestEngine and builder.
  • FiftyOne.Pipeline.Core.Tests - Tests for FlowElement and FlowData base classes.
  • FiftyOne.Pipeline.Engines.Tests - Tests for AspectEngines and AspectData base classes.
  • FiftyOne.Pipeline.Engines.FiftyOne.Tests - Tests for 51Degrees specific aspect engines.
  • FiftyOne.Pipeline.Examples.Tests - Tests for developer examples. This will automatically run all the examples and ensure they do not crash.
  • FiftyOne.Pipeline.Web.Tests - Tests for web integration functionality.

The tests can be run from within Visual Studio or (in most cases) by using the dotnet test command line tool.

Project documentation

For complete documentation on the Pipeline API and associated engines, see the 51Degrees documentation site.