Relativity Server SDK requirements

Custom applications for Relativity Server must be built with the correct Relativity Server SDK packages and, starting with Relativity Server 2026, must be packaged and validated with Server RAP Builder to remain within Relativity's supported build path. This page describes the SDK package requirements, the Server 2026 support policy, and how to update your applications.

Effective with the Relativity Server 2023 release, the NuGet packages required to extend core functionality and implement custom applications for Relativity Server are published and maintained separately from the SDKs hosted on the Relativity NuGet Gallery (nuget.org). The latest SDKs for Relativity Server will be hosted on a regional Relativity Server Artifactory Feed, while the Relativity NuGet Gallery will continue to host the Relativity aiR packages. Separating the Relativity aiR and Relativity Server packages provides for a more stable and reliable developer experience as each platform evolves.

The Relativity Server Artifactory Feed packages can be accessed from the following URLs:

You are not required to recompile your custom application against the Relativity Server Artifactory Feed-hosted packages for your application to work on Relativity Server 2025. However, we do recommend recompiling to consume the Relativity Server Artifactory Feed packages if it is a viable option, to ensure that your application is running against the latest Relativity Server SDKs. Moving forward, Relativity Server SDK packages will only be updated and enhanced on the Relativity Server Artifactory Feed sites. Custom applications compiled against the packages hosted on the NuGet Gallery may continue to work on future Relativity Server releases, but we recommend adopting the new Server packages as soon as possible, and strongly advise against updating any Server applications to consume new or updated versions of packages from nuget.org moving forward.

To ensure long-term compatibility, stability, and supportability of the Relativity Server platform, Relativity has recommended the use of Relativity Server SDKs and the Relativity Server Artifactory Feed for custom application development since Relativity Server 2023.

Beginning with Relativity Server 2026 GA, this guidance is reinforced through support policy enforcement.

Relativity strongly recommends that all custom Relativity Server applications (RAPs) be built using Relativity’s supported Relativity Server Artifactory Feed packages and Server RAP Builder, Relativity's supported application build and validation tool. For an introduction to the tool, see the Server RAP Builder Overview.

While alternative build approaches will not be blocked for Server 2026, RAPs that are not built and validated using Server RAP Builder and Artifactory Feed will be considered unsupported. Accordingly, Relativity Support and Engineering will not provide troubleshooting assistance for issues related to third-party RAPs that:

  • Are built against Relativity aiR code paths
  • Use custom or unmanaged dependency configurations
  • Are compiled outside of Server RAP Builder and Artifactory Feed
  • Do not target .NET Framework 4.8.1 (.NET Framework 4.8.1 is required for Server 2026)

Any RAP deployed to Relativity Server without being built using Server RAP Builder and the Relativity Server Artifactory Feed will fall outside of Relativity’s support policy starting in Relativity Server 2026.

See the topic Relativity Server SDK Requirements for information on SDKs for Relativity Server 2026, and comparing the available SDKs from the Relativity Server Artifactory repository and the Relativity One repository at nuget.org.

Using Relativity aiR packages in Relativity Server 2024/2025 is not recommended, and doing so is at your own risk.

Server RAP Builder and compatibility verification

Server RAP Builder (relsvr-rap) is a command-line tool for building Relativity Application Packages (RAPs) targeting Relativity Server. It validates application components, verifies that assemblies reference the correct Server SDK package versions for the targeted release, checks that assemblies target the required .NET Framework version (4.8.1 for Server 2026), and produces a properly structured .rap file. RAP Builder records its validation results inside the RAP, and it is the only mechanism by which Relativity can recognize a RAP as compliant.

Starting with Server 2026, Relativity reads these validation results when a RAP is uploaded and displays an Application Compatibility Check pop-up describing the application's compliance status before installation. Applications that were compiled against the correct Server SDKs but packaged without Server RAP Builder are still flagged as unsupported. Applications built entirely within the Relativity front end, with no custom resource files, are exempt from these requirements.

For more details, see the following topics:

Server SDK Support Policy

While using the dedicated Server SDKs hosted in Artifactory is recommended for Server 2023, Server 2024 and Server 2025, it is required and enforced starting with Server 2026. This section establishes the support policy and expectations for the Relativity Server SDK packages.

  • Starting with Server 2023 Release, SDK packages will be published to new Server-specific, public Artifactory NuGet and NPM feeds.
  • Server packages will not be published to nuget.org.
  • Naming conventions:
    • All SDK package identifiers use the Relativity.Server.* prefix.
      • example: Relativity.Server.Agent.SDK
    • Kepler-based SDK package identifiers append the .Interfaces.SDK suffix.
      • example: Relativity.Telemetry.MetricsCollection.Interface → Relativity.Server.Telemetry.MetricsCollection.Interface.SDK
    • Library-based SDK package identifiers append the .SDK suffix.
      • example: Relativity.Server.Application.SDK
    • Assembly filenames are not required to follow the package identifier, but are recommended for new SDKs.
      • example Relativity.Server.Agent.SDK continues to include kCura.Agent.dll
  • Versioning
    • SDK packages will continue using Semantic Versioning strategy.
    • To identify Relativity version compatibility, PackageTags are used.
  • Compatibility
    • This policy is limited to applications that build against SDK packages published to the new Artifactory public feed.
    • The SDK release is only guaranteed to be compatible with the current/next release + patches/hotfixes.
    • The policy is effective starting with Server 2023.
  • Breaking changes
    • Any breaking changes are announced at least 90 days before next EA release.
  • Publishing cadence
    • Pre-release SDK packages are published on or before EA release. Gold SDK packages are published on or before GA release.
  • Packaging and validation (Server 2026)
    • Starting with Server 2026, RAPs that contain custom code must be built and validated with Server RAP Builder in addition to consuming the Artifactory Feed SDK packages, and assemblies must target .NET Framework 4.8.1.
    • Compliance is evaluated when a RAP is uploaded and surfaced through the Application Compatibility Check. See Application Compatibility Verification in Relativity.

Updating your application to use packages from Artifactory

This section outlines how you can start adopting the Relativity Server SDK packages hosted on Relativity Server Artifactory Feed. Advantages of compiling your Relativity Server custom application against the Antifactory packages include:

  • Ensuring compatibility with the latest version of Relativity Server
  • Enabling you to take advantage of Relativity Server SDK enhancements and fixes

Custom applications that only target Relativity Server

For custom applications that only target Relativity Server we recommend updating your application to consume the packages hosted on the Relativity Server Artifactory Feed.

Follow these steps to compile your application against the Relativity Server SDK packages:

  1. Download the sample nuget.config from here (rename file to nuget.config after downloading). Refer to the Microsoft article on Package Source Mapping for more detail on using a nuget.config file.
  2. Copy the nuget.config file to your project repository root directory.
  3. Open your project or solution using Visual Studio 2022 or Rider.
  4. Update the versions used by your project with the latest versions available from the Relativity Server Artifactory Feed (this should also automatically restore them locally). In most cases, the package name will change, but the version will remain the same.
  5. For Server 2026, update your projects to target .NET Framework 4.8.1.
  6. Rebuild your project or solution.
  7. Commit your changes if the build was successful.
  8. For Server 2026, build and validate your RAP with Server RAP Builder as the final packaging step. See Getting Started with Server RAP Builder.

Custom applications that target both Relativity Server and Relativity aiR (multi-targeting)

Some customers choose to maintain a single version of a custom application for use in Relativity Server and Relativity aiR. While we continue to accommodate this strategy, developers will need to update their projects in order to consume the separate Relativity Server and Relativity aiR SDK packages.

Follow these steps to update your application to consume the separate Relativity Server and Relativity aiR SDK packages:

  1. Update your build tools to Visual Studio 2022 to enable NuGet 6 source mapping feature (this step is strongly recommended to guarantee that the correct packages are consumed).
  2. Create separate branches for Relativity Server and Relativity aiR.
  3. Switch to your Relativity Server branch.
  4. Download the nuget.config from here (rename file to nuget.config after downloading). Refer to the Microsoft article on Package Source Mapping for more detail on using a nuget.config file.
  5. Copy the nuget.config file to the project repository root directory.
  6. Open your project or solution using Visual Studio 2022 or Rider.
  7. Update the versions used by your project with the latest versions available from the Relativity Server Artifactory Feed (this should also automatically restore them locally).
  8. Rebuild your project or solution.
  9. Commit your changes if the build was successful.
For Server 2026, the Relativity Server build of a multi-targeted application must target .NET Framework 4.8.1 and be packaged with Server RAP Builder. RAP Builder is supported only for applications that run in Relativity Server environments; it does not build Relativity aiR packages. Keep your Relativity aiR packaging process unchanged on the Relativity aiR branch.

FAQ

Electing to not compile against the Relativity Server Artifactory Feed packages will not in itself prevent a custom application from working on Relativity Server 2023. However, as the Relativity Server and Relativity aiR platforms evolve, it is highly recommended that you adopt the new multi-targeting strategy detailed above to ensure compatibility across both platforms.

You can find a list of supported Relativity aiR SDKs for Server 2023 here.

To ensure long-term platform compatibility, Relativity will eventually require Relativity Server custom applications to be compiled against the Relativity Server Artifactory Feed packages. Starting with Server 2026, this requirement is enforced through Relativity's support policy: applications that are not compiled against the Artifactory Feed packages and not built with Server RAP Builder fall outside the supported build path, although installation is not blocked. See Server SDK Support Policy.

The SDK packages that are initially published on the Relativity Server Artifactory Feed in September 2023 will work for older supported versions of Relativity Server. Relativity will provide advance notification before introducing any breaking changes that would impact package compatibility with any supported versions of Relativity Server.

You are not prevented from recompiling a Relativity Server custom application against updated NuGet Gallery packages but Relativity cannot guarantee that breaking changes for Relativity Server have not been introduced, so it is strongly recommended that you avoid this action. If you ever plan to recompile a custom application for Relativity Server in the future you should do so using the Relativity Server Artifactory Feed packages.

Clear your local nuget caches using the Windows terminal with command dotnet nuget locals all --clear. Remove, or comment-out, the clear element from the nuget.config file, save it, and try to rebuild again. Your 3rd party packages should then be found, but be careful not to restore Relativity aiR packages coming from nuget.org. Only use Relativity Server packages from the Relativity Server Artifactory Feed. The restore order must be Relativity Server packages first, followed by any others.

Build the RAP with Server RAP Builder targeting the 2026 release. The tool validates your assemblies, SDK versions, and target framework during the build and reports any issues. When the RAP is uploaded to a Server 2026 environment, the Application Compatibility Check pop-up displays its compliance status. See Application Compatibility Verification in Relativity.

No. Applications that contain no custom resource files, including frontend-built applications exported from a pre-Server 2026 environment or from Relativity aiR, are not subject to the Server SDK or Server RAP Builder requirements and are treated as compliant.

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