[Home](../) › [Blog](../blog) › Metalama 2026.0 Generally Available: Full Support for C# 14 and .NET 10 # Metalama 2026.0 Generally Available: Full Support for C# 14 and .NET 10 > Announcing the general availability of Metalama 2026.0: full support for C# 14 extension blocks, .NET 10, and Visual Studio 2026; event handler overriding; first-class tuple support; Claude Code skill for AI-assisted development. Published: 2026-01-05 · Author: Gaël Fraiteur · Canonical: https://postsharp.net/blog/metalama-2026-0-ga Metalama 2026.0 is now generally available! This major release brings full support for C# 14 (the most significant evolution of the C# language in years), along with .NET 10 SDK and Visual Studio 2026 compatibility. We're also closing one of the last feature gaps with PostSharp: the ability to override event handler invocations. And you're getting first-class support for tuple types. Ready to try it? The packages are on [NuGet.org](https://www.nuget.org/packages/Metalama.Framework), and the Visual Studio extension is available from the [Visual Studio Marketplace](https://marketplace.visualstudio.com/items?itemName=PostSharpTechnologies.PostSharp). For the complete list of changes, see the [release notes](https://doc.metalama.net/conceptual/release-notes/release-notes-2026-0). For even more detail, see the change notes for the releases [2026.0.11](https://github.com/metalama/Metalama/releases/tag/release%2F2026.0.11), [2026.0.10-rc](https://github.com/metalama/Metalama/releases/tag/release%2F2026.0.10-rc), [2026.0.9-rc](https://github.com/metalama/Metalama/releases/tag/release%2F2026.0.9-rc), [2026.0.8-rc](https://github.com/metalama/Metalama/releases/tag/release%2F2026.0.8-rc), [2026.0.7-rc](https://github.com/metalama/Metalama/releases/tag/release%2F2026.0.7-rc), [2026.0.6-rc](https://github.com/metalama/Metalama/releases/tag/release%2F2026.0.6-rc), [2026.0.5-preview](https://github.com/metalama/Metalama/releases/tag/release%2F2026.0.5-preview), [2026.0.4-preview](https://github.com/metalama/Metalama/releases/tag/release%2F2026.0.4-preview), [2026.0.3-preview](https://github.com/metalama/Metalama/releases/tag/release%2F2026.0.3-preview), [2026.0.2-preview](https://github.com/metalama/Metalama/releases/tag/release%2F2026.0.2-preview), [2026.0.1-preview](https://github.com/metalama/Metalama/releases/tag/release%2F2026.0.1-preview). ## C# 14 support C# 14 introduces several language features, and Metalama 2026.0 supports all of them _in user code_: - Extension blocks (see below) - Null-conditional assignments - `field` keyword in properties - Partial constructors and events - Compound assignment operators - Simple lambda parameters with modifiers However, some features are **not yet supported in aspects**: - Null-conditional assignments in templates - The `field` keyword in templates - Generating run-time code for extension members via invoker interfaces - Adding contracts to the receiver parameter of extension blocks - Introducing new compound assignment operators - Introducing parameters into partial constructors - Introducing new extension blocks ## Extension blocks Extension blocks are the headline feature of C# 14, letting you extend any type with new members. Metalama supports them: - Extension blocks are modeled via the `IExtensionBlock` interface, which implements `INamedType` (`TypeKind = Extension`). - They appear under `INamedType.ExtensionBlocks`. - You can override extension members using the advising API or apply aspects via custom attributes. - You can introduce new members into existing extension blocks. - Introducing _new_ extension blocks is not yet supported. Here's how to add logging to all extension methods in your project using a fabric: ```csharp public class Fabric : ProjectFabric { public override void AmendProject( IProjectAmender amender ) { amender .SelectTypes() .SelectMany( t => t.ExtensionBlocks ) .SelectMany( e => e.Methods ) .AddAspectIfEligible(); } } ``` ## Event handler overriding You can now override event handler invocations, enabling patterns like "safe events" where each handler is isolated by exception handling. The `OverrideInvoke` method in `OverrideEventAspect` intercepts individual handler invocations. Typical use cases: - Safe events (exception isolation) - Background or asynchronous event dispatch - Event invocation logging Here's an aspect that catches exceptions and removes faulty handlers: ```csharp public class SafeEventAttribute : OverrideEventAspect { public override dynamic? OverrideInvoke( dynamic? handler ) { try { return meta.Proceed(); } catch ( Exception e ) { Console.WriteLine( e ); meta.Target.Event.Remove( handler ); throw; } } } ``` Apply it to any event: ```csharp public class Camera { [SafeEvent] public event EventHandler? FocusChanged; private void OnFocusChanged() { this.FocusChanged?.Invoke( this, EventArgs.Empty ); } } ``` For details, see [Overriding events](https://doc.metalama.net/conceptual/aspects/advising/overriding-events). ## First-class tuple support Previously, Metalama treated tuples as plain `INamedType` objects, with no access to element names or types. The new `ITupleType` interface changes that, making scenarios like packing method arguments for interceptors much cleaner: ```csharp // Create a tuple type from method parameters. var tupleType = TypeFactory.CreateTupleType( method.Parameters ); // Create a tuple instance. var tupleExpression = tupleType.CreateCreateInstanceExpression( meta.Target.Parameters ); // Pass it to an observer. _myObserver.OnMethodCalled( method.DeclaringType.FullName, method.Name, tupleExpression.Value ); ``` ## Metrics enhancements - **LinesOfCode metric**: Three measurements (Logical, NonBlank, and Total). - **Workspaces API**: Now officially supports metrics consumption. ## Visual Studio tooling improvements We've refactored several background components of our VSIX. It's now more stable, consumes less CPU, and better utilizes your cores. ## Claude Code skill for AI-assisted development We're introducing a Claude Code skill that gives Anthropic's AI assistant Metalama knowledge: - Conceptual documentation - API references - Sample code and pattern libraries Whether you're new to Metalama or tackling a complex scenario, Claude can now provide contextually relevant guidance for aspect development, templates, fabrics, and the code model. The skill is available on the [Metalama.AI.Skills marketplace](https://github.com/metalama/Metalama.AI.Skills). For setup instructions, see [Configuring Claude Code](https://doc.metalama.net/conceptual/using/claude-code). ## Documentation updates We've made these improvements: - New: [Working with types](https://doc.metalama.net/conceptual/aspects/type-system) - Improved: [Writing T# templates](https://doc.metalama.net/conceptual/aspects/templates) - Updated: [Injecting dependencies into aspects](https://doc.metalama.net/conceptual/aspects/dependency-injection) (now covers cross-project DI) - Updated: [Overriding events](https://doc.metalama.net/conceptual/aspects/advising/overriding-events) - New: [Consuming code metrics](https://doc.metalama.net/conceptual/introspection/metrics) and [Custom metrics](https://doc.metalama.net/conceptual/sdk/custom-metrics) - Enhanced API docs with integrated conceptual content ## Breaking changes - .NET 6 SDK is no longer supported. - Several API and behavioral changes. See the [release notes](https://doc.metalama.net/conceptual/release-notes/release-notes-2026-0) for details. ## What's next With 2026.0 shipped, we'll focus on extending C# 14 support in aspects. Found an issue or have a feature request? Let us know on [GitHub](https://github.com/metalama/Metalama/issues). Happy meta-programming! -gael --- ## Site navigation - Index of the whole site: [llms.txt](../llms.txt)