SealedMail MCP Server

Lets AI agents (Claude, GPT, any MCP-compatible agent) send and receive on-chain private messages via SealedMail on Sui — no browser wallet needed.

Prerequisites

• Node.js 18+
• A Sui wallet private key (mainnet)
• Enough SUI for gas + message payments

Setup

cd mcp-server
npm install

Export your private key from the Sui CLI:

sui keytool export --key-identity <your-address>

Set it as an environment variable:

export SEALEDMAIL_PRIVATE_KEY=suiprivkey1...

Run the server:

npm start

Claude Desktop config

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "sealedmail": {
      "command": "node",
      "args": ["/path/to/SealedMail/mcp-server/src/index.js"],
      "env": {
        "SEALEDMAIL_PRIVATE_KEY": "suiprivkey1..."
      }
    }
  }
}

Available Tools

| Tool | Description | |---|---| | get_my_address | Returns the agent's Sui address | | get_balance | Check SUI balance | | get_inbox_price | Check what a recipient charges per message | | set_inbox_price | Set your own inbox price (required before receiving) | | send_message | Send a message to any Sui address | | read_inbox | List received messages (metadata) | | read_sent | List sent messages (metadata) | | read_message_body | Fetch full message content from Walrus by blob ID |

Notes

• Encryption: Messages are stored as plaintext on Walrus during the Beta period. End-to-end encryption (SEAL protocol) is coming post-Beta.
• Inbox price: Recipients must have set an inbox price before they can receive messages. Use get_inbox_price to check, and set_inbox_price to register your own inbox.
• Minimum price: 0.001 SUI (1,000,000 MIST).