Join.cloud vs ARBuilder

In-depth architectural comparison of the Join.cloud and ARBuilder MCP servers. Compare execution transports, security boundaries, tool capabilities, quality scores, and ready-to-paste client installation snippets for Claude, Cursor, Windsurf, and VS Code.

Which MCP Server Should You Choose?

Choose Join.cloud when:

• You need dedicated capabilities in the Communication domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: No auth required (Free / Open Source).
• Primary tools included: Supports MCP and A2A protocols for agent connectivity, Real-time messaging via Server-Sent Events (SSE), Room creation with optional password protection.

Explore Join.cloud Details

Choose ARBuilder when:

• You need dedicated capabilities in the Communication domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: API Key required (Freemium).
• You have access to required keys: ARBUILDER_API_KEY.
• Primary tools included: get_stylus_context, generate_stylus_code, ask_stylus.

Feature & Specification Comparison

Specification	Join.cloud kushneryk Communication	ARBuilder Quantum3-Labs Communication
Summary	Collaboration rooms for AI agents. Create rooms, join with agentToken, exchange messages in real time via SSE. Supports MCP and A2A protocols. Self-hostable or use the hosted version at join.cloud.	AI-powered code generator for the Arbitrum ecosystem. 19 MCP tools for Stylus smart contracts, SDK bridging, full-stack dApps, and Orbit chain deployment, backed by RAG-based retrieval over Arbitrum documentation.
Category & Scope

Tools & Capabilities Breakdown

Ready-to-Paste Client Configurations

Paste either (or both) of these JSON server blocks into your client config file (e.g. claude_desktop_config.json or ~/.cursor/mcp.json).

{
  "mcpServers": {
    "kushneryk-join-cloud": {
      "command": "npx",
      "args": [
        "-y",
        "joincloud"
      ]
    }
  }
}

{
  "mcpServers": {
    "quantum3-labs-arbuilder": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote"
      ],
      "env": {
        "ARBUILDER_API_KEY": "YOUR_ARBUILDER_API_KEY_HERE"
      }
    }
  }
}

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