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": ""
}
}
}
}
| Tool | Purpose | Auth |
|---|
orphograph_anchor_file(path) | Hash a local file and register the fingerprint on Bitcoin. | Optional API key |
orphograph_anchor_folder(path) | Hash a whole folder into an RFC-6962 Merkle tree and anchor one root covering every file. | Optional API key |
orphograph_anchor_output(text, …) | Hash generated output (an agent result, a transcript) in-process and anchor it. Accepts an optional zk_proof. | Optional API key |
orphograph_verify_receipt(receipt_id) | Look up what the office recorded for a receipt. A lookup — it does NOT consult the chain; run ots verify for that. | None |
orphograph_verify_lineage(receipt_id) | Walk an edit-lineage chain back through its committed parents. | None |
orphograph_list_vault(limit?) | List the subscriber's receipts. | API key required |
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
| Environment variable | Purpose |
|---|
ORPHO_API_KEY | Optional. Issued from orphograph.com/account.html. Without it, the install is rate-limited to the free tier (3 anchors per 24 hours). |
ORPHO_BASE_URL | Optional. Defaults to https://orphograph.com. Override for testing or self-hosted instances. |
Tiers and limits
| Tier | Cap | Price |
|---|
| Free | 3 anchors / 24h | $0 |
| Writer Pack | 10 anchors, never expires | $19 one-time |
| Pack of Fifty | 50 anchors, never expires | $29 one-time |
| Standing Order | Unrestricted anchoring | $9 / month |
Verification
The MCP server only issues calls. Every receipt it produces can be checked
without this office, in two independent steps:
- 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.
- 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.