Deaddrop

deaddrop-mcp

MCP server that lets AI agents (Claude Code, Claude Desktop, anything MCP-capable) share secrets through DeadDrop - self-destructing one-time links, paid per call with USDC over x402.

Two tools:

• deaddrop_create_secret - encrypts the secret locally (AES-256-GCM), pays $0.01 in USDC via x402, returns a one-time link. The link works exactly once, then the secret is destroyed.
• deaddrop_reveal_secret - consumes a one-time link and decrypts locally. Free, no wallet needed.

Zero-knowledge end to end: the AES key is generated in this process and travels only in the link fragment (#...); the payer wallet key also stays here. The DeadDrop server only ever sees ciphertext and an x402 payment.

Install

git clone https://github.com/jerrywrongalot-byte/deaddrop-mcp
cd deaddrop-mcp
npm install

Configure

Claude Code:

claude mcp add deaddrop -e DEADDROP_PAYER_KEY=0x<key> -- node /absolute/path/to/deaddrop-mcp/server.mjs

Claude Desktop / any MCP client (.mcp.json / claude_desktop_config.json):

{
  "mcpServers": {
    "deaddrop": {
      "command": "node",
      "args": ["/absolute/path/to/deaddrop-mcp/server.mjs"],
      "env": { "DEADDROP_PAYER_KEY": "0x<key>" }
    }
  }
}

Environment

Variable	Meaning
DEADDROP_PAYER_KEY	EVM private key holding USDC on Base. Needed only for CREATE (it pays $0.01/secret); reveal works without it.
DEADDROP_NETWORK	base (default) or base-sepolia for testing.
DEADDROP_BASE_URL	Override the service URL (defaults to the live service).

Wallet safety (read this)

• Use a dedicated key with a small USDC balance (a few dollars covers hundreds of secrets), not a main wallet. The key signs real payments.
• Payments are gasless for the payer (EIP-3009): the key needs USDC only, no ETH.
• x402-fetch enforces a max-payment cap (default 0.10 USDC per call), so a rogue or mistyped server URL cannot drain the key.
• The service never receives the key OR the plaintext - see the API's agent-facing spec at /llms.txt.

Example

"Drop this API key for my coworker: sk-live-... - 1 day expiry"

The agent calls deaddrop_create_secret, pays a cent, and hands back https://deaddrop.../s/<id>#<key>. First open reveals and destroys it; link previewers can't burn it (reveal is an explicit action).

License

MIT