Directory vs Nullary

In-depth architectural comparison of the Directory and Nullary 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 Directory when:

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

Explore Directory Details

N

Choose Nullary 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 Nullary Details

Feature & Specification Comparison

Specification	Directory Developer Tools	N Nullary Developer Tools
Summary	Discover and query every business on ANOTS — search, ask, or find-and-ask over MCP.	Negative results intelligence for drug discovery — query measured failures via MCP.
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": {
    "directory": {
      "url": "http://localhost:6333/health"
    }
  }
}

{
  "mcpServers": {
    "nullary-2": {
      "command": "npx",
      "args": [
        "-y",
        "nullary-2"
      ]
    }
  }
}

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