Agentcairn vs Penfield MCP

In-depth architectural comparison of the Agentcairn 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 Agentcairn when:

• You need dedicated capabilities in the Knowledge & Memory domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: No auth required (Free / Open Source).
• Primary tools included: Plain Markdown Obsidian vault as canonical memory store, Rebuildable DuckDB index for hybrid BM25, vector, and graph recall, Non-lossy memory capture with supersession and secret redaction.

Explore Agentcairn 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	Agentcairn ccf Knowledge & Memory	Penfield MCP penfieldlabs Knowledge & Memory
Summary	Local-first agent memory: a plain-Markdown Obsidian vault is the source of truth, with a rebuildable DuckDB index for hybrid BM25 + vector + graph recall. Non-lossy capture with secret redaction; works across Claude Code, Codex, Cursor, and any MCP host. uvx agentcairn	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": {
    "ccf-agentcairn": {
      "command": "uvx",
      "args": [
        "agentcairn"
      ]
    }
  }
}

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

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