Introduction
The AF SDK has been a core component for building custom applications on top of the AVEVA PI System. For years, development with the AF SDK has been based on the .NET Framework, which shaped how custom applications were built and deployed within the PI System ecosystem.
With the release of AF SDK for .NET 8, AVEVA introduces a new option for developers to build applications using the latest .NET ecosystem. This change does not replace the existing SDK but rather adds a parallel path for modern development.
AF SDK for .NET 8: Release Overview
AVEVA has released a new version of the AF SDK built for .NET 8, distributed as a NuGet package. This marks a significant shift from the traditional model, where the SDK was installed as part of the PI AF Client.
The new version is designed to maintain feature parity with the existing .NET Framework SDK. According to AVEVA, both versions are being developed and maintained in parallel, with consistent behavior and compatibility expectations across them.
At the same time, this is not a complete redesign of the SDK. The primary change is the runtime and packaging model, enabling developers to build applications using modern .NET versions while continuing to interact with the same PI AF infrastructure.
Compatibility and Migration
From a compatibility standpoint, AVEVA indicates that the .NET 8 AF SDK is expected to work with the same PI AF Server versions supported today. While an official compatibility matrix has not yet been published, there is no indication of breaking changes in server support.
Applications built with the .NET Framework version of AF SDK are not directly compatible with the .NET 8 version, meaning a rebuild is required to target the new NuGet package. As a result, migration is not automatic and should be approached as a development effort rather than a simple upgrade. This means organizations need to plan and validate changes as part of their application lifecycle.
It is also important to note that existing AVEVA products such as PI Vision, Analysis Service, and PI Web API will continue to rely on the .NET Framework versions. The .NET 8 SDK is currently intended for custom application development only.
Key Differences Between SDK Versions
Although AVEVA states that feature parity is largely maintained, there are some important differences developers need to be aware of.
The .NET 8 version is distributed as a NuGet package, removing the need for a full client installation. However, this also means that configuration is handled differently, and some setup steps must be managed at runtime rather than during installation.
There are also functional differences. The .NET 8 SDK does not include UI components or dialog-based interactions, and interoperability with the legacy PI SDK has been removed. Methods related to PI SDK integration, such as AFValue.ToPIValue() and AFAttribute.RawPIPoint, are no longer available.
In addition, some behavioral differences arise from the .NET runtime itself. These include higher precision in time calculations, changes in floating-point formatting, and differences in string handling due to globalization libraries.
What This Means for Industrial Teams
The release of AF SDK for .NET 8 gives development teams more flexibility in how they build and evolve custom PI System applications, particularly for projects that require alignment with modern .NET ecosystems or integration with newer technologies. Rather than replacing existing implementations, it introduces an additional development path that can be adopted where it provides clear benefits.
MetaFactor has extensive experience building AF SDK-based applications and can support the evaluation and transition of custom solutions to .NET 8, helping teams determine where modernization adds value and how to implement it safely within their existing environments. If you are assessing this transition or planning next steps, you can contact us.