What is the key difference between Unpaywall and MCP Registry Server?

Unpaywall belongs to the Developer Tools category with local stdio execution, while MCP Registry Server belongs to the Developer Tools category with cloud HTTP/SSE execution.

How do I install Unpaywall or MCP Registry Server in Claude Desktop or Cursor?

Copy the mcpServers JSON configuration snippet provided on this page into your claude_desktop_config.json or ~/.cursor/mcp.json file and restart your AI client.

Are Unpaywall and MCP Registry Server free or paid?

Unpaywall operates under a Free / Open Source model (No auth required). MCP Registry Server operates under a Free / Open Source model (No auth required).

Which MCP server has more tools and community activity?

Unpaywall lists 0 tools with 0 views and 0 GitHub stars. MCP Registry Server lists 0 tools with 0 views and 7,133 GitHub stars.

Can I use both Unpaywall and MCP Registry Server together in the same MCP host?

Yes! MCP hosts like Claude Desktop, Cursor, Windsurf, Cline, and VS Code support configuring multiple servers under the mcpServers object simultaneously.

How do I install Unpaywall or MCP Registry Server in Claude Desktop, Cursor, or Windsurf?

Both servers follow the standard Model Context Protocol configuration format. Simply copy the JSON block from the configuration section above and paste it into your AI client's mcpServers configuration object (for instance in claude_desktop_config.json or ~/.cursor/mcp.json ), then completely restart or refresh the application.

Are Unpaywall and MCP Registry Server free to use, or do they require API keys?

Unpaywall is listed under a Free / Open Source model with No auth required . MCP Registry Server operates under a Free / Open Source model with No auth required . If environment variables are required (such as API keys), be sure to define them under the env key in your MCP client's configuration file.

Can I run both Unpaywall and MCP Registry Server at the same time in my AI client?

Yes! MCP clients support multi-server orchestration. You can include both unpaywall and mcp-registry-server as distinct keys inside the single mcpServers object in your configuration file. Your AI assistant will automatically select and call the appropriate tool from either server during chat sessions.

Which MCP server has higher directory engagement and quality ratings?

On AllMCPs, Unpaywall has a Quality Score of 27 /100 ( Emerging ) with 0 views, 0 installs, and 0 GitHub stars. MCP Registry Server holds a Quality Score of 48 /100 ( Fair ) with 0 views, 0 installs, and 7,133 GitHub stars.

Side-by-Side Model Context Protocol Comparison

Unpaywall vs MCP Registry Server

In-depth architectural comparison of the Unpaywall and MCP Registry Server 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.

At a Glance & Executive Verdict

Unpaywall

Developer Tools · Local stdio

Quality: 27/100 (Emerging) | Auth: No auth required

MCP Registry Server

Developer Tools · Remote HTTP/SSE

Quality: 48/100 (Fair) | Auth: No auth required

Verdict Summary: Choose Unpaywall if you need specialized Developer Tools tools running via a local process. Choose MCP Registry Server if your workspace requires Developer Tools integration with remote web transport. Both servers can be configured concurrently in your client's mcpServers manifest.

Which MCP Server Should You Choose?

Choose Unpaywall 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 Unpaywall Details

Choose MCP Registry Server 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 MCP Registry Server Details

Feature & Specification Comparison

Specification	U Unpaywall Developer Tools	M MCP Registry Server Developer Tools
Summary	Open-access availability for 120M+ scholarly articles via the Unpaywall API	Publish and discover MCP servers via the official MCP Registry. Powered by HAPI MCP server.
Category & Scope	Developer Tools	Developer Tools
Quality signal

Tools & Capabilities Breakdown

Unpaywall Tools (0)

No explicit tool names declared in metadata yet. Check project README on main listing page.

MCP Registry Server Tools (0)

No explicit tool names declared in metadata yet. Check project README on main listing page.

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).

Unpaywall Configuration

mcpServers (Claude Desktop / Cursor)

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

MCP Registry Server Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "mcp-registry-server": {
      "url": "https://registry.modelcontextprotocol.io/docs"
    }
  }
}

Frequently Asked Questions

Unpaywall is categorized under Developer Tools and uses a local stdio subprocess. In contrast, MCP Registry Server belongs to Developer Tools using remote streaming HTTP/SSE transport. Select Unpaywall when you need capabilities focused on developer tools and MCP Registry Server when you require tools for developer tools.

More alternatives to Unpaywall More alternatives to MCP Registry Server Developer Tools category hub Canonical compare URL

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