Antigravity × MCP Ecosystem 2026: Complete Practical Guide— Server Selection, Integration, and Custom Development

2. 2026 MCP Server Catalog

Development & Code Management

GitHub MCP Server (official)

{
  "github": {
    "command": "npx",
    "args": ["-y", "@modelcontextprotocol/server-github"],
    "env": { "GITHUB_PERSONAL_ACCESS_TOKEN": "YOUR_GITHUB_TOKEN" }
  }
}

Key tools: search_repositories, get_file_contents, create_issue, create_pull_request, list_commits

GitLab MCP Server

{
  "gitlab": {
    "command": "npx",
    "args": ["-y", "@modelcontextprotocol/server-gitlab"],
    "env": {
      "GITLAB_PERSONAL_ACCESS_TOKEN": "YOUR_GITLAB_TOKEN",
      "GITLAB_API_URL": "https://gitlab.com"
    }
  }
}

Database

PostgreSQL MCP Server (official)

{
  "postgres": {
    "command": "npx",
    "args": [
      "-y", "@modelcontextprotocol/server-postgres",
      "postgresql://user:pass@localhost/mydb"
    ]
  }
}

SQLite MCP Server

{
  "sqlite": {
    "command": "npx",
    "args": ["-y", "@modelcontextprotocol/server-sqlite", "--db-path", "./data.db"]
  }
}

Communication & Collaboration

Slack MCP Server

{
  "slack": {
    "command": "npx",
    "args": ["-y", "@modelcontextprotocol/server-slack"],
    "env": {
      "SLACK_BOT_TOKEN": "xoxb-YOUR_SLACK_BOT_TOKEN",
      "SLACK_TEAM_ID": "T_YOUR_TEAM_ID"
    }
  }
}

Notion MCP Server

{
  "notion": {
    "command": "npx",
    "args": ["-y", "@notionhq/client-mcp"],
    "env": { "NOTION_API_KEY": "YOUR_NOTION_KEY" }
  }
}

Browser & Web

Puppeteer MCP Server

{
  "puppeteer": {
    "command": "npx",
    "args": ["-y", "@modelcontextprotocol/server-puppeteer"]
  }
}

Brave Search MCP Server

{
  "brave-search": {
    "command": "npx",
    "args": ["-y", "@modelcontextprotocol/server-brave-search"],
    "env": { "BRAVE_API_KEY": "YOUR_BRAVE_API_KEY" }
  }
}

3. Multi-MCP Integration Patterns

Pattern 1: Research → Code → PR Automation

# Prompt to Antigravity

"Please execute the following:
1. Search Brave for 'React Server Components best practices 2026'
2. Summarize the top 3 articles' key points
3. Review the project's src/components/ directory
4. Implement improvements based on the best practices
5. Create a new GitHub branch and open a PR:
   Title: 'feat: Apply RSC best practices 2026'"

Brave Search + Filesystem + GitHub MCP makes this a single AI-driven workflow.

Pattern 2: Data Analysis → Slack Report Automation

"Every Monday at 9am:
1. Query PostgreSQL orders table for last week's revenue
2. Calculate week-over-week change and goal attainment rate
3. Post a formatted report to Slack #weekly-report"

PostgreSQL MCP + Slack MCP fully automates recurring reports.

Pattern 3: Auto-Documentation

"For this PR's changes:
1. Create a new page in Notion 'Engineering Docs' database
2. Document changes, design intent, and impact in Markdown
3. Link and close related GitHub issues
4. Send a completion notification to Slack #engineering"

4. MCP Server Selection Criteria

Evaluation Checklist

Trustworthiness

• Official servers (@modelcontextprotocol/server-*) or established vendor?
• GitHub stars, last updated, issue response rate

Security

• Credentials handled via environment variables?
• Principle of least privilege (requests only necessary scopes)
• Always review source code of third-party servers

Feature Coverage

• Does it cover your specific use case?
• Rate limit and pagination support

Performance

• Response speed (does it block for long periods?)
• Caching support

5. Building a Custom MCP Server

A Custom MCP Server in Under an Hour

// my-custom-mcp-server/src/index.ts
import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import {
  CallToolRequestSchema,
  ListToolsRequestSchema,
} from "@modelcontextprotocol/sdk/types.js";
 
const server = new Server(
  { name: "my-company-api", version: "1.0.0" },
  { capabilities: { tools: {} } }
);
 
server.setRequestHandler(ListToolsRequestSchema, async () => ({
  tools: [
    {
      name: "get_product_inventory",
      description: "Get inventory count for a product",
      inputSchema: {
        type: "object",
        properties: {
          productId: { type: "string", description: "Product ID" },
          warehouseId: { type: "string",
            description: "Warehouse ID (omit for all warehouses)" },
        },
        required: ["productId"],
      },
    },
    {
      name: "create_support_ticket",
      description: "Create a new support ticket",
      inputSchema: {
        type: "object",
        properties: {
          title: { type: "string" },
          description: { type: "string" },
          priority: { type: "string",
            enum: ["low", "medium", "high", "critical"] },
          assigneeEmail: { type: "string" },
        },
        required: ["title", "description", "priority"],
      },
    },
  ],
}));
 
server.setRequestHandler(CallToolRequestSchema, async (request) => {
  const { name, arguments: args } = request.params;
 
  switch (name) {
    case "get_product_inventory": {
      const { productId, warehouseId } = args as {
        productId: string; warehouseId?: string;
      };
      const inventory = await fetchInventory(productId, warehouseId);
      return { content: [{ type: "text",
        text: JSON.stringify(inventory, null, 2) }] };
    }
    case "create_support_ticket": {
      const result = await createTicket(args);
      return { content: [{ type: "text",
        text: `Ticket #${result.id} created. URL: ${result.url}` }] };
    }
    default:
      throw new Error(`Unknown tool: ${name}`);
  }
});
 
const transport = new StdioServerTransport();
await server.connect(transport);

Register in Antigravity Settings

{
  "mcpServers": {
    "my-company-api": {
      "command": "node",
      "args": ["/path/to/my-custom-mcp-server/dist/index.js"],
      "env": {
        "COMPANY_API_KEY": "YOUR_INTERNAL_API_KEY",
        "API_BASE_URL": "https://api.internal.company.com"
      }
    }
  }
}

6. MCP Security in Production

Environment Variable Best Practices

# .env.antigravity (must be in .gitignore)
GITHUB_PERSONAL_ACCESS_TOKEN=ghp_YOUR_PERSONAL_ACCESS_TOKEN
SLACK_BOT_TOKEN=xoxb_YOUR_BOT_TOKEN
NOTION_API_KEY=secret_YOUR_NOTION_KEY

Least-Privilege Scope Design

# GitHub token scopes
✅ repo   — read/write private repos
❌ admin:org — never needed for most use cases
❌ delete_repo — never grant this

# Slack app scopes
✅ chat:write — send messages
✅ channels:read — list channels
❌ admin — workspace admin privileges not needed

Frequently Asked Questions

Q: Does the MCP server run inside Antigravity?

A: No. MCP servers run as separate processes and communicate with Antigravity over stdio or SSE. This means you can write MCP servers in any language — TypeScript, Python, Go, etc.

Q: Does having many MCP tools hurt AI performance?

A: Yes. More available tools means more context for the AI to reason about, which can slow responses and increase costs. Only enable the servers you actually need and disable others in your config.

Q: Are there risks to using third-party MCP servers?

A: Yes. A malicious MCP server could exfiltrate credentials or make unintended API calls. Stick to official servers (@modelcontextprotocol/server-*) or established vendors, and always review source code for unknown servers before use.

Q: How do I debug a custom MCP server?

A: Use @modelcontextprotocol/inspector — an interactive debugger for MCP servers. Run it with npx @modelcontextprotocol/inspector node dist/index.js to inspect tools, execute them manually, and validate responses.

A Note from an Indie Developer

Key Takeaways

Key takeaways for leveraging the 2026 MCP ecosystem with Antigravity:

• Evaluate servers on trustworthiness, security, feature coverage, and performance before adopting
• Combine MCP servers (search + code + GitHub, DB + Slack, etc.) to automate complex multi-step workflows
• Enforce least privilege — assign only the minimum required scopes to each MCP server
• Build custom MCP servers to integrate internal APIs and extend Antigravity's reach