Install the mcpindex gate in Claude, Cursor, Gemini CLI, Cline, or Zed

The mcpindex gate sits in your MCP host session so each configured server launches behind a contract pin. On first sight it records the tool contract. On later calls it diffs the live contract and HOLDs when a silent breaking change appears — before the agent acts on the new shape.

Two jobs, do not confuse them:

1. Gate (this guide) — in-path HOLD via install.sh / mcpindex-gate. Auto-wires Claude Desktop, Claude Code, Cursor, Gemini CLI (~/.gemini/settings.json), Cline, Zed, Windsurf, and VS Code. 2. Directory client — advisory discovery only: claude mcp add --scope user mcpindex -- npx -y mcp-server-mcpindex@latest or gemini mcp add -s user mcpindex npx -y mcp-server-mcpindex@latest

Convenience gate install (inspect first):

curl -fsSL https://mcpindex.ai/install.sh | less

Then run the same URL piped to sh, or follow the auditable path in the docs: uv tool install mcpindex-gate plus the host-config wizard. The script rewrites MCP host config only; uninstall.sh restores it. No API key. The gate does not take custody of your provider tokens.

After install, restart the host when required (Claude Desktop/Code, Zed, Gemini CLI). When a tool drifts, you get a HOLD with a ChangeKind — review, re-pin, or validate. The blast-radius grade (read/write/delete/send, reversible or not) is advisory and never overrides HOLD/PROCEED.

This is not a malware scanner and not a guarantee the tool is safe. It is a deterministic contract-diff in the path.

Full wiring notes: https://mcpindex.ai/docs#install-the-gate