How do I install Otskit?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Otskit need an API key?

No required environment variable is listed on this record.

What transport does Otskit use?

Otskit runs locally over stdio.

Otskit MCP server

Q: When was Otskit last checked?

Last checked 2026-11-08. Stamp, upgrade, and verify Bitcoin timestamps via AI agents. No API keys required.

Power your agent

Add this server

The publisher's own command. Not a PlugMCP endpoint.

Add to Cursor Add to VS Code Run on PlugMCP

Host a copy with our keys and logs.

Local command

npx -y @otskit/[email protected]

Claude Code has no install link for a local command. Copy the command below and run it in a terminal.

shClaude Code

1claude mcp add io.github.alexalves87-otskit-mcp -- npx -y @otskit/mcp@0.2.1

Run in a terminal.

jsonClaude Desktop

1{2  "mcpServers": {3    "io.github.alexalves87-otskit-mcp": {4      "command": "npx",5      "args": [6        "-y",7        "@otskit/[email protected]"8      ]9    }10  }11}

claude_desktop_config.json

Local · npmPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
Version: 0.2.1
Last checked

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

@otskit/mcp

OpenTimestamps MCP server - stamp, upgrade, and verify Bitcoin timestamps via AI agents.

Exposes a set of tools to any MCP-compatible agent so it can timestamp documents, monitor confirmation status, and verify proofs against the Bitcoin blockchain - all from a conversation.

This is an independent implementation of the OpenTimestamps protocol. It is not affiliated with, endorsed by, or maintained by the OpenTimestamps project.

Note on confirmation times: After stamping, a proof is pending until Bitcoin confirms it. Confirmations typically arrive within ~60 minutes, but can take several hours during network congestion. Use ots-mcp watch or upgrade_timestamp to monitor. A pending proof is not a failed proof.

Install

npm install -g @otskit/mcp

Agent setup

ots-mcp setup claude        # Claude Desktop
ots-mcp setup claude-code   # Claude Code CLI
ots-mcp setup codex         # Codex CLI

Each command writes the MCP entry into the agent's config file, makes a .bak backup if the file already exists, and skips if ots-mcp is already configured. Restart the agent afterwards to apply the changes.

CLI commands

Command	Description
`ots-mcp serve`	Start the MCP server (stdio transport)
`ots-mcp stamp <sha256>`	Stamp a SHA-256 hash against Bitcoin calendars
`ots-mcp upgrade <id>`	Check if a pending stamp has been confirmed
`ots-mcp verify <id>`	Verify a stamp against Bitcoin
`ots-mcp list [status]`	List stamps (`pending` / `confirmed` / `failed`)
`ots-mcp watch [minutes]`	Monitor pending stamps and attempt due upgrades (default: 30 min, minimum: 15 min)
`ots-mcp check-pending`	Run one upgrade pass over all pending stamps
`ots-mcp scheduler install\|remove\|status`	Manage OS-level scheduler for auto-upgrades
`ots-mcp backup [dest]`	Backup the SQLite database
`ots-mcp setup <claude\|claude-code\|codex>`	Configure MCP for an agent

MCP tools exposed to agents

Tool	Description
`create_timestamp`	Stamp a SHA-256 hash against 4 public OTS calendars
`upgrade_timestamp`	Check if a pending stamp has been confirmed in Bitcoin
`verify_timestamp`	Verify a stamp - proves hash existed before a given Bitcoin block
`verify_external_proof`	Verify a whitelisted local file against its external `.ots` proof, without changing the local stamp store
`inspect_timestamp`	Inspect a stored proof file without network calls
`list_pending`	List stamps with status, retry count, and filters
`watch`	Open a terminal window monitoring pending stamps and attempting due upgrades
`hash_file`	Compute the SHA-256 of a local file and return it as a 64-char hex string (no network calls)
`stamp_file`	Compute SHA-256 of a local file and stamp it on Bitcoin in one step

Data directory

All data is stored in ~/.ots-mcp/:

~/.ots-mcp/
  ots-mcp.db       # SQLite database (stamps, proof files)
  config.json      # Optional config overrides
  ots-mcp.log      # Log file

Configuration

Create ~/.ots-mcp/config.json to override defaults:

{
  "stamp_enabled": true,
  "scheduler_interval_minutes": 30,
  "retry_max_attempts": 20,
  "calendar_timeout_ms": 10000,
  "calendars": [
    "https://alice.btc.calendar.opentimestamps.org",
    "https://bob.btc.calendar.opentimestamps.org",
    "https://finney.calendar.eternitywall.com",
    "https://btc.calendar.catallaxy.com"
  ]
}

Development

npm run build    # production build
npm run dev      # watch mode
npm test         # run tests

Dependencies

@otskit/client - OTS calendar client (brings in @otskit/core, the protocol engine)
@modelcontextprotocol/sdk - MCP SDK
node-sqlite3-wasm - local database (pure WASM, no native compilation)

Requires Node.js >= 20.

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Otskit?

Does Otskit need an API key?

What transport does Otskit use?

When was Otskit last checked?

Documentation

@otskit/mcp

Install

Agent setup

CLI commands

MCP tools exposed to agents

Data directory

Configuration

Development

Dependencies