Tc39 MCP vs Valet

In-depth architectural comparison of the Tc39 MCP and Valet 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 Tc39 MCP when:

• You need dedicated capabilities in the Developer Tools domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: No auth required (Free / Open Source).

Explore Tc39 MCP Details

Choose Valet when:

• You need dedicated capabilities in the Developer Tools domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: No auth required (Freemium).

Explore Valet Details

Feature & Specification Comparison

Specification	Tc39 MCP Developer Tools	Valet Developer Tools
Summary	Structural TC39 spec lookup (ECMA-262 + ECMA-402) for AI agents — SHA-pinned, offline-first.	Get share links, publish and manage websites, artifacts and agents. No account needed.
Category & Scope	Developer Tools	Developer Tools
Quality signal

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": {
    "tc39-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "tc39-mcp"
      ]
    }
  }
}

{
  "mcpServers": {
    "valet": {
      "command": "npx",
      "args": [
        "-y",
        "skills"
      ]
    }
  }
}

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