Editor Setup

Editor Setup

Cadenza does not ship its own language layer. It rides the base Roslyn LSP that the official C# extension is built on, so completion, hover, go-to-definition, and diagnostics light up for every Cadenza SDK as long as that extension is active and pointed at file-based apps.

TL;DR

Editor	What you need
VS Code (stock)	Install ms-dotnettools.csharp, ensure "Use Modern .NET Tooling" is on.
Cursor / Kiro / forks	Install the community-rebuilt C# extension (no Dev Kit license). See below.
Rider / VS	Works out of the box with .NET 10 SDK.

The C# Dev Kit is not required.

VS Code

1. Install ms-dotnettools.csharp (just "C#", not "C# Dev Kit").
2. Open a folder containing your .cs file.
3. Open the file. The status bar should show the Roslyn LSP starting.
4. Type #:sdk Cadenza. — the completion should suggest Cadenza, Cadenza.Web, Cadenza.Mcp, etc.

TODO: confirm whether any settings need to be flipped on for file-based apps as of 10.0.300 GA.

Cursor, Kiro, and other VS Code forks

The official C# extension is gated to Microsoft-branded builds. For forks, use the community rebuild:

• Open VSX: dotnetdev-kr-custom/csharp (built via vscode-csharp-autobuild)
• After install, disable OmniSharp and confirm Roslyn LSP is active (Command Palette → "C#: Open Output" → look for [Info] Starting Roslyn LSP).

Debugging caveat

vsdbg (Microsoft's debugger) is licensed for Microsoft-branded builds only. On forks, debugging via the official path is restricted. If you need step debugging in a fork, point the launch config at the muhammad-sammy/csharp build which uses netcoredbg instead.

TODO: drop in a working launch.json snippet for forks.

JetBrains Rider

Cadenza file-based apps work as of Rider 2025.3+. Open a folder containing .cs files — Rider treats them as standalone scripts.

TODO: confirm Rider's exact minimum version once .NET 10 GA support lands.

Visual Studio (full IDE)

TODO: confirm support story; Visual Studio's file-based app integration is still rolling out.

See also

• Installation
• Directives — what the editor is completing when you type #:sdk
• FAQ — "Why isn't completion working?"