Modernized Runtime

Connexion v16 and earlier used .NET Framework. Connexion v26 targets .NET 10, providing a modern runtime for cross-platform services, container deployment, streaming, and asynchronous processing.

Modern .NET is also cross-platform, which has allowed us to add support for Linux. This has enabled us to include support for container technologies such as Docker and Kubernetes.

The runtime change requires existing v16 device plugins to be migrated and rebuilt for v26. See Plugin Developers: What You Need to Know for v26 for the project structure, API changes, and migration examples.

What changed

Services (Connexion, Gateway, Remote Agent, etc) target .NET 10 and are cross-platform.
User interface applications also now target .NET 10 and are cross platform.
Connexion is now x64-only. Legacy x86 execution groups are not part of the v26 runtime model.
Device plugins have moved from a single project model which includes both UI and runtime to a 2-project model - runtime and UI.

What this enables

Capability	Why it matters

Capability	Why it matters
Linux support	The server-side runtimes can now run outside Windows. This in turn allows us to target platforms like Kubernetes to allow dynamic scaling.
Cost Efficacy	With support for Linux and Postgres, Connexion can be deployed on platforms which have lower initial and operating costs. Additional support for dynamic scaling allows you to scale Connexion clusters up/down based on demand.
Modern hosting	v26 can use current .NET hosting patterns, including Windows Services, systemd, ASP.NET Core hosting, gRPC services, health checks, and modern configuration providers.
Performance headroom	.NET 10 gives Connexion current JIT, GC, tiered compilation, async streams, channels, pipelines, and newer memory APIs. This is the foundation for lower-allocation message paths, streaming transports, and improved startup and steady-state behavior.
Simpler dependency graph	Many .NET Framework-era dependencies and vendored libraries were removed or replaced with actively maintained packages that support modern .NET.
Cleaner future feature work	New platform work can assume a modern runtime instead of carrying .NET Framework compatibility branches. Features such as gRPC streaming, OpenTelemetry, MCP tooling, containerization, and cross-platform service hosting all depend on this foundation.

Performance improvements

v26 improves message-processing throughput and UI responsiveness. See Performance Improvements for the 1,000-channel v16/v26 comparison, original screenshots, and the changes to startup, scrolling, device editing, queue batching and large-message handling.

What changed for deployment

Windows deployment continues through the Windows service and desktop tooling model (Installers & Wizards).
Linux packaging includes local Debian-package and archive build paths. Headless installations use command-line configuration; Avalonia desktop clients, configuration wizards and trays are also available. Installing a local .deb with apt is separate from providing a hosted apt repository.
Self-contained Linux artifacts and container images can be used for container deployments.

What changed for custom plugins and custom code

Custom plugins built for v16 / .NET Framework must be ported to v26 / .NET 10.
Plugin projects should move to SDK-style projects and target net10.0, and UIs now use Avalonia in place of WPF (Avalonia is very familiar to WPF).
The .NET framework large monolithic Connexion libraries have been refactored into more appropriate smaller projects/assemblies. Most of the non-core namespaces have changed.

v26 provides assisted upgrade paths for v16 custom code. Importing a v16 package or encountering a compilation failure can offer a code upgrade, and migration checks identify removed APIs and reference changes. Review and test the converted code; custom plugins must be migrated and rebuilt for the v26 API and runtime. Plugin migration guidance is also available to AI development tools.

Support context

Microsoft lists .NET 10 as a long-term support release, supported for three years.
Modern .NET has an annual release cadence, with even-numbered releases on the long-term support track.
.NET Framework 4.8.1 remains supported as a Windows component, but it keeps Connexion tied to Windows and the older framework ecosystem.