launch

Code OSS Dev - Launch + Debug

You're working on VS Code itself and you want to:

1. Launch a Code OSS build from sources that is already signed in (Copilot, GitHub, etc.) so chat / agent flows work end-to-end.
2. Drive it with @playwright/cli over CDP (UI automation).
3. Optionally attach a debugger via dap-cli to set breakpoints in the renderer, extension host, or main process.
4. Run multiple instances at once without port conflicts.

This skill provides a launcher that clones an authenticated user-data-dir to a throwaway temp folder, picks free ports for every debug surface, and prints them as JSON so you can pick them up programmatically.

The clone is slim: workspace storage, browser caches, file history, cached VSIX backups, and old logs are excluded by default. On macOS, auth tokens live in the OS keychain plus small files inside User/globalStorage - both of which are preserved. On Windows the GitHub session lives in the shared-data-dir instead, which the launcher seeds separately (see Windows authentication).

Prerequisites

• macOS, Linux, or Windows.
  • macOS / Linux: the launcher is a bash script (scripts/launch.sh) and depends on rsync, nohup, and Node on PATH. The example caller snippets below also use jq (parse the JSON output) and lsof (kill-by-port fallback) — install those if you plan to use them, but the launcher itself does not require them.
  • Windows: use scripts\launch.ps1 instead. It needs no extra tooling beyond Node on PATH, and works on both Windows PowerShell 5.1 and PowerShell 7+. jq is not needed — parse the JSON with ConvertFrom-Json. If Node is managed with fnm, put it on PATH first:

    fnm env --use-on-cd --shell powershell | Out-String | Invoke-Expression
    fnm use   # picks up the repo's .nvmrc
    

• A VS Code checkout with node_modules/ installed (npm install if missing — do not symlink from a sibling worktree; that breaks builds in subtle ways).
• A VS Code checkout with sources built. Run npm run compile once (one-shot) or npm run watch for incremental rebuilds. Both build the full client and all built-in extensions under extensions/. You must build the full product to run successfully, building just the client is not enough.
• An authenticated Code OSS profile to seed from. By default the launcher uses ~/.vscode-oss-dev on macOS/Linux or $env:USERPROFILE\.vscode-oss-dev on Windows, which is the user-data-dir the repo's launch.json configs use - if the user has ever signed in to Copilot in a dev build, this should work. Only pass --source-user-data-dir <path> (or set $CODE_OSS_DEV_AUTHED_USER_DATA_DIR) when you specifically want to seed from a different profile (e.g. your regular ~/Library/Application Support/Code install).
  • If Code OSS launches and needs a sign-in, don't give up! Use the questions tool to ask the user to sign in.
• @playwright/cli available (it's a devDependency in the vscode repo - npm install then use npx @playwright/cli).
• For debugger work: dap-cli on PATH. If debugger support would be useful but the dap-cli skill is not present, prompt the user to install it from https://github.com/roblourens/dap-cli.
• CSS selectors are internal implementation details. If a selector-based eval stops working, take a fresh snapshot, inspect the current DOM, and update the selector rather than assuming an old one still applies.