NCI
Integrations · Cursor

Wire NCI into Cursor

Drop one MCP entry into Cursor and the agent can ask exact questions about the libraries you have installed without leaving the editor. The server inherits NCI’s config-driven database resolution, so each open workspace gets the right index automatically.

Add the MCP server

Edit ~/.cursor/mcp.json, or open CursorSettingsMCP:

{
  "mcpServers": {
    "nci": {
      "command": "npx",
      "args": ["-y", "@nativecontextindex/mcp"]
    }
  }
}

That is the whole entry. nci-mcp reads the open workspace through the same logic nci uses for nci.config.json — there is no NCI_PROJECT_ROOT env var.

If nci is not on Cursor’s PATH, point at the binary explicitly:

{
  "mcpServers": {
    "nci": {
      "command": "npx",
      "args": ["-y", "@nativecontextindex/mcp"],
      "env": {
        "NCI_BINARY": "/absolute/path/to/nci"
      }
    }
  }
}

Find the absolute path with:

nci

Apply changes

Cursor watches mcp.json and rebuilds the server list when you save — no app restart needed. Open CursorSettingsMCP to confirm nci is listed with two tools and three resources. If the toggle row looks stuck, the command palette’s Developer: Reload Window is the only escalation you should ever need.

Best-practice prompts

  • “Look up ZodObject.omit in the version of zod we have installed before writing the schema.”
  • “List the public exports of @my-org/shared so I can decide what to import.”
  • “Find every overload of useState and tell me which packages provide it.”

The agent picks the right nci_query subcommand. Pin package_name and package_version in the prompt when you want exact answers fast — the agent primer goes into more detail on why.

Re-index on demand

NCI’s tools read the database; they do not build it. Re-run nci index whenever the lockfile changes:

nci

For monorepo setups see Monorepo indexing.

Troubleshooting

If Cursor reports the wrong NCI version or “binary not found”, set NCI_BINARY to the path printed by nci binary-path. The Node shim and nci-mcp both defer to it.

Skills

Cursor follows the open Agent Skills standard. NCI’s shipped skill (nci-answer-quality) drops into Cursor’s discovery path with no rewriting — see NCI Skills for the host-by-host map.