MCP Server vs Just MCP

In-depth architectural comparison of the MCP Server and Just MCP 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 MCP Server when:

• You need dedicated capabilities in the Code Execution domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: No auth required (Free / Open Source).
• Primary tools included: Isolated execution in WebAssembly sandboxes, Configurable CPU (compute) allocation levels, Memory and timeout limits per task.

Explore MCP Server Details

Choose Just MCP when:

• You need dedicated capabilities in the Code Execution domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: No auth required (Free / Open Source).
• Primary tools included: Full MCP 0.3.0 protocol server implementation, Recipe discovery and listing from Justfiles, Recipe execution with parameter support and structured output.

Feature & Specification Comparison

Specification	MCP Server mavdol/capsule Code Execution	Just MCP promptexecution Code Execution
Summary	Run untrusted Python/JavaScript code in WebAssembly sandboxes.	Justfile integration that enables LLMs to execute any CLI or script commands with parameters safely and easily, with environment variable support and comprehensive testing.
Category & Scope	Code Execution

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": {
    "mavdol-capsule-mcp-server": {
      "command": "uvx",
      "args": [
        "capsule-run"
      ]
    }
  }
}

{
  "mcpServers": {
    "promptexecution-just-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "just-mcp"
      ]
    }
  }
}

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