CatchDoms — Expired Domains API vs Spanlens

In-depth architectural comparison of the CatchDoms — Expired Domains API and Spanlens 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 CatchDoms — Expired Domains API when:

• You need dedicated capabilities in the Monitoring domain.
• You prefer remote streaming HTTP/SSE transport architecture.
• Your security boundary fits: API Key required (Freemium).
• Primary tools included: search_domains, get_domain, list_filters.

Explore CatchDoms — Expired Domains API Details

Choose Spanlens when:

• You need dedicated capabilities in the Monitoring domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: API Key required (Free / Open Source).
• You have access to required keys: SPANLENS_API_KEY.
• Primary tools included: Seven read-only observability tools, Request log queries, Agent trace inspection.

Feature & Specification Comparison

Specification	CatchDoms — Expired Domains API Monitoring	Spanlens spanlens Monitoring
Summary	Search 40K+ expired domains from 12 auction platforms with SEO metrics and scores.	Query your Spanlens LLM observability from any MCP client. 7 read tools for request logs, agent traces, cost stats, anomalies, model-savings, and per-user analytics across OpenAI, Anthropic, and Gemini. Open source, self-hostable. npx -y @spanlens/mcp-server
Category & Scope	Monitoring

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": {
    "catchdoms-expired-domains-api": {
      "url": "https://catchdoms.com/mcp/catchdoms/free"
    }
  }
}

{
  "mcpServers": {
    "spanlens-spanlens-2": {
      "command": "npx",
      "args": [
        "-y",
        "@spanlens/cli"
      ],
      "env": {
        "SPANLENS_API_KEY": "YOUR_SPANLENS_API_KEY_HERE"
      }
    }
  }
}

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