Unity Debugger Pure

An independent, community-maintained VS Code debugger for managed C# code in local Unity 2022 and Tuanjie Editors. This project is not affiliated with, endorsed by, or supported by Unity Technologies or Unity China.

It provides Unity Editor attach without requiring C# Dev Kit or Microsoft's Unity extension. ReSharper for VS Code can remain installed for code analysis, navigation, and refactoring; this extension owns only the unity-debugger-pure debug type. Its Marketplace extension ID is kpk.unity-debugger-pure.

Install

Install Unity Debugger Pure from one of these sources:

• Visual Studio Marketplace for VS Code;
• Open VSX for Open VSX-compatible editors;
• Cursor's Extensions view, which obtains this extension from Open VSX.

For sideloading, download unity-debugger-pure-0.3.3.vsix from the GitHub Releases page, run Extensions: Install from VSIX..., and select that exact file.

Before attaching, set the Editor's Code Optimization mode to Debug and open the Unity/Tuanjie project root in VS Code.

Use Run and Debug: Add Configuration... and select the provided attach configuration:

{
  "name": "Attach to Unity Debugger Pure",
  "type": "unity-debugger-pure",
  "request": "attach",
  "projectPath": "${workspaceFolder}"
}

Start debugging with F5. If more than one supported local Editor is running, VS Code asks which instance to attach to.

Unity Debugger Pure: Attach Unity Debugger lists the Unity Editors and Players available for debugger attachment; pick one to start a session.

A Player, or an Editor that discovery cannot see, can be reached by naming its debugger endpoint explicitly:

{
  "name": "Attach to Unity Debugger Pure",
  "type": "unity-debugger-pure",
  "request": "attach",
  "endPoint": "127.0.0.1:56321"
}

projectPath defaults to the workspace folder and selects the project the debugger maps sources against. logFile redirects this session's sanitized diagnostics log to a path you choose.

Features

• local Windows x64 Editor discovery and attach, plus Player attach by an explicit endPoint;
• Unity Debugger Pure: Attach Unity Debugger, which lists the Unity Editors and Players available for debugger attachment;
• source and conditional breakpoints, with the reference debugger's warning when function breakpoints are in use;
• step in, step over, step out, pause, and continue;
• threads, call stacks, locals, expandable variables, watch, and REPL evaluation;
• all-exception and user-unhandled-exception break modes;
• breakpoint rebinding across Domain Reload: the mature debugger session owns rebinding, rather than a reload-specific mechanism in the adapter;
• Unity Debugger Pure: Unity API Reference, which opens the Unity documentation for the selected code construct;
• a Unity Debugger Pure output channel, and the unity-debugger-pure.displayBackgroundProcesses setting — contributed for manifest compatibility, and inert until the adapter emits the background classification it filters on;
• sanitized local diagnostics with no telemetry.

Version 0.3.3 exposes a versioned local extension API for trusted local clients. API targets are opaque, restricted to the current workspace, and do not change normal interactive debugging.

Implicit evaluation

Hover, Locals, variable expansion, Watch, and Debug Console use the mature debugger session's built-in evaluation behavior. Property getters and target ToString() calls can execute code in the paused debug target and may have side effects or delays. There is no separate implicit-evaluation setting.

Support policy

Formally supported:

• Windows 10/11 x64;
• Tuanjie 2022.3.62t11;
• Mono managed C# debugging;
• attaching to a discovered local Editor, and to an explicit host:port endpoint — including a Player's, since the reference reaches a Player by probing the device for its debugger port and no advertisement observed so far carries one.

Unity 2022.3 LTS versions are accepted for compatibility testing. Unity 6 is allowed to connect but is unverified and is not guaranteed. The Adapter warns for versions outside the formal baseline, and separately — naming no baseline — when the Editor version cannot be determined at all.

Currently excluded: IL2CPP, WebGL, Tuanjie Mini Game DebugProxy, native C++, multiple simultaneous Editors, and non-Windows platforms.

Android and iOS are a different case rather than the same one. The path exists — a debug-enabled Player advertisement, including an Android one, is discoverable — but attaching to one has never been verified end to end, so no Android or iOS attach is claimed.

Security and privacy

Attaching to an endpoint other than a discovered loopback one is supported: an explicit endPoint in launch.json may name any ip:port, including one on another machine.

Unity's managed debug transport has no authentication. Anyone who can reach the debugger port can attach to that Editor or player, and an attached debugger can execute code in the target. An endpoint exposed on a network interface is therefore reachable by anyone who can route to it. The port is derived deterministically from the Editor's process id (56000 + pid % 1000), so it is guessable rather than secret. Prefer loopback, and expose a remote endpoint only on a network you trust and control. The extension adds no authentication, and this section is not a guarantee that a remote endpoint is safe to expose.

The extension has no telemetry — the reference debugger reports usage, and this one does not, by design. Diagnostics are written under %LOCALAPPDATA%\unity-debugger-pure\logs (or to the configured logFile path), retain five files, redact user profile and workspace paths, and never record source text, expressions, evaluation results, or variable values.

Use:

• Unity Debugger Pure: Open Sanitized Diagnostics
• Unity Debugger Pure: Copy Sanitized Diagnostics

When reporting an issue, include only the sanitized diagnostics plus Editor, extension, Windows, and reproduction information. Do not paste project source or raw variable data.

Build from source

Requirements: Windows x64, Node.js 26.5.0, .NET SDK 10.0.401 (pinned in global.json), and npm.

npm ci
dotnet restore UnityDebugger.sln --locked-mode
npm test
npm run package

The real Mono argument-evaluation regression tests use a standalone console fixture and do not open an Editor. Set UNITY_DEBUGGER_TEST_MONO to an existing mono.exe (for example, the Editor's Data/MonoBleedingEdge/bin/mono.exe) before npm run test:adapter to include them. Without this executable, those tests are reported as skipped. Their temporary fixture files and processes are removed after each test.

The package pipeline builds the Adapter from audited source, stages production assemblies only, verifies the committed runtime inventory, audits VSIX paths and hashes, and emits a SHA-256 file.

License

Project code is MIT licensed. The bundled THIRD_PARTY_NOTICES.md contains pinned upstream sources and runtime dependency notices.