Passenger

Passenger is an open-source IDE for C# and .NET, built with Avalonia and published by Zaneris under the MIT licence. It runs on Windows, macOS and Linux, and its latest release is v0.3.0. Version 0.3.0 adds Godot 4 support for C# and GDScript, Blazor WebAssembly debugging in the browser, and XAML Hot Reload for Avalonia and WPF.

What It Is

Passenger is a full .NET IDE with a Roslyn-powered C# editor, its own debugger with Hot Reload, and a CPU and memory profiler. It also provides XAML tooling for Avalonia and WPF, Git, search, NuGet, unit-test and terminal windows, and language-server support for web languages such as TypeScript, HTML, CSS, JSON and YAML. The site says it collects no telemetry and needs no account.

Godot, Debugging and Profiling

For Godot 4 games, Passenger runs, debugs, profiles and Hot Reloads C# and GDScript. It checks C# against the game's scenes and reads GDScript and shaders as Godot's own parser and compiler do. A Live Visual Tree shows the running game's nodes and values. The debugger supports conditional breakpoints, Smart Step Into, returned values, attach to running processes and decompiled libraries. The profiler samples through EventPipe to produce call trees, flame graphs and compared heap snapshots.

Containers, Aspire and Web Apps

Compose files, Dockerfiles and Aspire AppHosts become run configurations, and each .NET service can be debugged, reloaded and profiled inside its container. For ASP.NET Core and EF Core, a Requests window lists live requests with their SQL and marks N+1 queries, and a Migrations window handles EF Core migrations.

Agent Integration

Passenger acts as an MCP server so agents such as Claude Code, Codex and OpenCode can work through the IDE. They can navigate and rename code, build, test, debug and profile. For Avalonia apps, Godot games and WPF apps on Windows, an agent can see and drive the running program with screenshots, control trees, clicks and keys.

Setup Path

Downloads are provided for Windows (x64, Arm64), macOS on Apple Silicon, and Linux (x64, Arm64). Projects need a .NET SDK 8 or later. Git is needed for version control, Node.js for web languages, Godot 4 for Godot games, a Chromium browser for Blazor WebAssembly debugging, and a container engine for container features. .NET Framework, Mono and Unity are not supported.