JetBrains released Rider 2026.3 on November 10, 2026, timed to match the general availability of .NET 11. The cross-platform .NET IDE supports .NET 11 and C# 15 from the first day, including the new union types and debugging for the runtime's new async model.
The release also brings JetBrains Air, the company's agent workspace, into Rider. New agent skills, test runs through the Rider MCP server and game development upgrades for Godot, Unreal-style C++ debugging and Lua round out the update.
.NET 11 and C# 15 Support
Rider 2026.3 understands the full .NET 11 toolchain without extra setup. On the language side, it covers new C# 15 features such as unions, closed hierarchies and extension indexers, with the usual code analysis and editing help.
The IDE can also debug code that uses Runtime Async, the new way .NET 11 handles asynchronous methods inside the runtime itself. JetBrains notes the details in the .NET section of its What's New page.
For background on the platform release, see our report on .NET 11 and C# 15 union types.
JetBrains Air Inside Rider
JetBrains Air is the agentic development layer that JetBrains is adding across its IDEs in the 2026.3 cycle. It lets developers give tasks to AI agents, coordinate several of them and review what they produce from within the IDE.
Rider also has a new Welcome screen, so you can start working with Air without first opening a solution. That suits quick experiments or tasks that do not belong to one project.
Agent Skills and MCP Updates
- More agent skills: Rider adds several new skills that agents can call while they work on .NET code.
- Tests through MCP: agents can now run tests using the Rider MCP server, so they can check their own changes.
- Worktree setup: when you create a Git worktree, Rider can carry your local project settings over to it, which helps when several agents or reviewers work on separate branches at once.
Game Development Improvements
- New plugins add Lua and Verse language support.
- Godot projects get a more complete debugging experience.
- The C++ debugger improves, including natvis support for custom type views.
- Command-line argument presets make it easier to switch between launch settings.
JetBrains has also launched a dedicated landing page for game development with Rider.
What It Means for Developers
Teams planning a .NET 11 move can now use Rider for that work straight away, without waiting for a later patch. Union types and closed hierarchies change how domain models are written, so having analysis and refactoring support from the start lowers the risk of early adoption.
Runtime Async debugging deserves a test of its own. If your services lean heavily on async code, step through a few common paths in Rider after upgrading to see how call stacks and breakpoints behave under the new model.
The agent features are most useful for teams already trying AI-assisted workflows. Letting an agent run tests through MCP, and giving each one its own configured worktree, turns agent output into something you can verify instead of just read.
Before upgrading production machines, check that your plugins and build scripts still work with 2026.3. Game studios using Godot or Lua should try the new plugins on a branch first.
How to Get Started
Rider 2026.3 can be downloaded now from the JetBrains website. Install the .NET 11 SDK separately if you want to target the new runtime, then open or create a project and set the target framework.
The full list of changes, grouped into AI, .NET and game development sections, sits on the Rider 2026.3 What's New page. JetBrains asks for feedback in the blog comments, on X or on Bluesky.
Conclusion
Rider 2026.3 arrives on the same day as .NET 11, with ready support for C# 15 unions and Runtime Async debugging. JetBrains Air, testable agent workflows and game development upgrades make it a broad release for .NET and game developers alike.
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