OneTime Secret MCP

What it does

OneTime Secret MCP renders an interactive UI inside Claude Desktop for creating and sharing encrypted secrets that automatically self-destruct after a configurable number of views or time limit. Recipients open a shareable link, enter a passphrase, and view the secret — all decryption happens client-side so the server never sees plaintext.

Key features

• Zero-knowledge encryption — Secrets are encrypted client-side with AES-256-GCM using PBKDF2-derived keys; the server only stores ciphertext
• Self-destructing links — Secrets expire after a time limit (up to 7 days) or a view count threshold
• MCP-native UI — Full interactive form inside Claude Desktop for creating secrets with passphrase, TTL, and max-views settings
• Standalone reveal page — Non-Claude recipients can decrypt secrets via a simple web interface served by a Cloudflare Worker
• Cloudflare KV backend — Serverless global-edge storage with automatic TTL expiration, no database to manage

Installation

Add to your Claude Desktop configuration:

{
  "mcpServers": {
    "onetimesecret": {
      "command": "npx",
      "args": ["-y", "onetimesecret-mcp"],
      "env": {
        "CLOUDFLARE_WORKER_URL": "https://your-worker.workers.dev"
      }
    }
  }
}

You'll also need to deploy the companion Cloudflare Worker for secret storage. Clone the repo, run npm run worker:create-kv then npm run worker:deploy, and set the resulting URL in the env above.

Supported hosts

• Claude Desktop (confirmed in README)