Orphograph MCP server

A single-file Model Context Protocol server that lets a Claude / Claude Code / Cursor / any-MCP-host instance anchor files to the Bitcoin chain via Orphograph without the file ever leaving the user's machine.

mcp-name: io.github.Orphograph/orphograph

• License: MIT
• Dependencies: Python ≥ 3.9 standard library only. Also on PyPI as orphograph-mcp 0.1.1.
• Lines of code: ~310, single file.
• Protocol: MCP 2024-11-05 over stdio.

Install

Save the script anywhere:

curl -sSL https://orphograph.com/mcp/orphograph_mcp.py -o ~/bin/orphograph_mcp.py

Then register it with your MCP host.

Claude Desktop (~/Library/Application Support/Claude/claude_desktop_config.json)

{
  "mcpServers": {
    "orphograph": {
      "command": "python3",
      "args": ["/Users/YOU/bin/orphograph_mcp.py"],
      "env": {
        "ORPHO_API_KEY": ""
      }
    }
  }
}

Claude Code

claude mcp add orphograph python3 /Users/YOU/bin/orphograph_mcp.py

Or edit ~/.claude/settings.json and add the same mcpServers block.

Cursor (~/.cursor/mcp.json)

{
  "mcpServers": {
    "orphograph": {
      "command": "python3",
      "args": ["/Users/YOU/bin/orphograph_mcp.py"],
      "env": {
        "ORPHO_API_KEY": ""
      }
    }
  }
}

Tools exposed

Privacy contract

• The file body never leaves the device.
• The script computes SHA-256 + SHA-512 in-process and transmits only those fingerprints to https://orphograph.com/api/anchor.
• The script makes no network call until a tool is explicitly invoked by the host.
• File reads stream in 1 MB chunks; large files do not load into memory.

Configuration

Tiers and limits

Verification

The MCP server only issues calls. Every receipt it produces can be checked without this office, in two independent steps:

1. Structure — the open-source verifier at github.com/Orphograph/Orphograph re-derives the hashes and checks the receipt offline. It makes no network calls of its own.
2. Chain — the OpenTimestamps client (ots verify) confirms the commitment actually landed in a Bitcoin block. The bundled verifier will invoke it for you when passed --ots.

Only step 2 consults Bitcoin.

Reporting issues

Open an issue at the public repo, or write to hello@orphograph.com.