antigravity-mcp-mastery

name	antigravity-mcp-mastery
description	Master Guide for Model Context Protocol (MCP) in Antigravity
source	https://antigravity.codes/blog/antigravity-mcp-tutorial
risk	safe

Antigravity MCP Mastery

Overview

This skill encapsulates the best practices for configuring, using, and building MCP servers within the Antigravity IDE. It enables the agent to connect to databases, cloud services, and custom local tools without context switching.

1. Configuration (mcp_config.json)

To add existing servers, edit your global or project-specific mcp_config.json.

Template: Supabase + Git

{
  "mcpServers": {
    "supabase": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-postgres",
        "postgresql://user:[e-mail]:5432/postgres" // Use env vars in production!
      ],
      "env": {
        // "PGPASSWORD": "your-password"
      }
    },
    "git-tool": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-server-git",
        "--repository",
        "/absolute/path/to/repo"
      ]
    }
  }
}

2. Building Custom MCP Servers

Use this boilerplate to create a Node.js/TypeScript server that exposes custom tools to the agent.

Prerequisites

npm install @modelcontextprotocol/sdk zod

Server Boilerplate (src/index.ts)

import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { ListToolsRequestSchema, CallToolRequestSchema } from "@modelcontextprotocol/sdk/types.js";
import { z } from "zod";

// Initialize Server
const server = new Server(
  { name: "custom-tool-server", version: "1.0.0" },
  { capabilities: { tools: {} } }
);

// Define Tools
server.setRequestHandler(ListToolsRequestSchema, async () => {
  return {
    tools: [
      {
        name: "check_status",
        description: "Checks system status",
        inputSchema: {
          type: "object",
          properties: {
            service: { type: "string", description: "Service name (api, db, cache)" }
          },
          required: ["service"]
        }
      }
    ]
  };
});

// Handle Tool Calls
server.setRequestHandler(CallToolRequestSchema, async (request) => {
  if (request.params.name === "check_status") {
    const service = request.params.arguments?.service;
    return {
      content: [{ type: "text", text: \`Service \${service} is OPERATIONAL\` }]
    };
  }
  throw new Error("Tool not found");
});

// Connect
const transport = new StdioServerTransport();
await server.connect(transport);

3. Best Practices

• Least Privilege: Only give tools access to necessary resources.
• Trusted Workspaces: Be cautious when running MCP servers in untrusted repositories.
• Context Pruning: Use specific tools rather than generic "read everything" tools to save token budget.