# deaddrop-mcp

MCP server that lets AI agents (Claude Code, Claude Desktop, anything
MCP-capable) share secrets through [DeadDrop](https://deaddrop.jerrywrongalot.workers.dev) -
self-destructing one-time links, paid per call with USDC over
[x402](https://www.x402.org).

![DeadDrop demo: a secret is created, shared as a link, and destroyed after one read](demo.gif)

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`):

```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](https://deaddrop.jerrywrongalot.workers.dev/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