VS Code, Cursor & Claude Desktop

VS Code, Cursor, and Claude Desktop configure MCP servers but expose no tool-call hook API, so there is no runtime guard for them — coverage is scan-only: ringzero-mcp scan discovers their configs, runs the full check set, and enforces the allowlist at scan time. All three are full MCP Registry sync targets, though — the org catalog configures approved servers in them too.

Where their configs live

Harness	Repo scope (scan)	Machine scope (scan --machine)
VS Code	.vscode/mcp.json	—
Cursor	.cursor/mcp.json	~/.cursor/mcp.json
Claude Desktop	—	claude_desktop_config.json in %APPDATA%\Claude\ (Windows), ~/Library/Application Support/Claude/ (macOS), ~/.config/Claude/ (Linux)

Editor-flavored JSON (comments, trailing commas) parses fine.

Config examples

VS Code uses a servers key:

.vscode/mcp.json

{
  "servers": {
    "web-search": {
      "command": "npx",
      "args": ["-y", "mcp-web-search-pro@1.4.2"]
    }
  }
}

Cursor and Claude Desktop use mcpServers (same shape as Claude Code’s .mcp.json):

.cursor/mcp.json

{
  "mcpServers": {
    "notion": {
      "command": "npx",
      "args": ["-y", "@notionhq/notion-mcp-server@1.8.0"],
      "env": { "NOTION_TOKEN": "${env:NOTION_TOKEN}" }
    }
  }
}

Why no runtime hooks

Claude Code has PreToolUse/PostToolUse hooks and OpenCode has a plugin API — both let RingZero sit in the host’s own extension mechanism without proxying MCP traffic. VS Code, Cursor, and Claude Desktop offer no equivalent today. RingZero deliberately does not wrap or proxy MCP servers to work around that: staying out of the request path is a design boundary, not a gap to patch with a shim.

Note

If one of these harnesses ships a hook API, the integration pattern is the same as the other two: identify MCP calls, evaluateToolCall() from @ringzero/mcp-scan, write audit records. The library is the addon SDK.

Recommended posture

1. Scan repo configs in CI — .vscode/mcp.json and .cursor/mcp.json are committed files; the CI gate reviews every change against the allowlist.
2. Run machine scans on dev workstations — ringzero-mcp scan --machine catches user-level Claude Desktop / Cursor servers that never appear in a repo. Schedule it (login script, dotfiles repo, MDM) and --upload the results if your org is connected.
3. Route agent work through hooked harnesses where auditing matters — Claude Code and OpenCode give you the full record; the others give you configuration hygiene.