Magic MCP vs Kcp Harness — KCP compliance proxy

In-depth architectural comparison of the Magic MCP and Kcp Harness — KCP compliance proxy 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 Magic MCP when:

• You need dedicated capabilities in the Developer Tools domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: API Key required (Paid Service).
• You have access to required keys: TWENTY_FIRST_API_KEY, API_KEY_21ST.
• Primary tools included: UI component generation, Component, theme, and template search, Design inspiration lookup.

Explore Magic MCP Details

K

Choose Kcp Harness — KCP compliance proxy 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).
• Primary tools included: kcp_plan, kcp_load, kcp_trace.

Explore Kcp Harness — KCP compliance proxy Details

Feature & Specification Comparison

Specification	Magic MCP 21st-dev Developer Tools	K Kcp Harness — KCP compliance proxy Developer Tools
Summary	Create crafted UI components inspired by the best 21st.dev design engineers.	MCP compliance proxy between agent and tools: deterministic governance, fail-closed, audit trail.
Category & Scope	Developer Tools	Developer Tools

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": {
    "21st-dev-magic-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@21st-dev/cli@latest"
      ],
      "env": {
        "TWENTY_FIRST_API_KEY": "YOUR_TWENTY_FIRST_API_KEY_HERE",
        "API_KEY_21ST": "YOUR_API_KEY_21ST_HERE"
      }
    }
  }
}

{
  "mcpServers": {
    "kcp-harness-kcp-compliance-proxy": {
      "command": "npx",
      "args": [
        "-y",
        "kcp-harness"
      ]
    }
  }
}

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