Cosmos MCP vs Penfield MCP

In-depth architectural comparison of the Cosmos MCP and Penfield MCP 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 Cosmos MCP when:

• You need dedicated capabilities in the Knowledge & Memory domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: API Key required (Free / Open Source).
• You have access to required keys: COSMOS_TOKEN.
• Primary tools included: Shared account-keyed personal knowledge graph, Eleven MCP read and write tools, Portable .polarity graph export.

Explore Cosmos MCP Details

Choose Penfield MCP when:

• You need dedicated capabilities in the Knowledge & Memory domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: OAuth 2.0 (Free / Open Source).
• Primary tools included: Persistent memory across sessions, Hybrid BM25, vector, and graph search, Knowledge graph with 24 relationship types.

Feature & Specification Comparison

Specification	Cosmos MCP teampolarity Knowledge & Memory	Penfield MCP penfieldlabs Knowledge & Memory
Summary	Personal knowledge graph shared across MCP clients. Account-keyed and portable as a .polarity file, with sources for iMessage, browser history, calendar, Claude Desktop transcripts, shell history, Notion, and Obsidian. npx -y @polarity-lab/cosmos-mcp	Penfield: persistent memory with hybrid search (BM25 + vector + graph), 24 relationship types for knowledge graphs, context checkpoints for cognitive handoff, artifact storage, and personality system. Works across Claude, Cursor, Windsurf, and any MCP client.
Category & Scope

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": {
    "teampolarity-cosmos-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@polarity-lab/cosmos-mcp"
      ],
      "env": {
        "COSMOS_TOKEN": "YOUR_COSMOS_TOKEN_HERE"
      }
    }
  }
}

{
  "mcpServers": {
    "penfieldlabs-penfield-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote"
      ]
    }
  }
}

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