MCP Money – A Nostr‑Powered Cashu Wallet for AI Assistants

MCP Money fills a critical gap for developers building AI assistants that need to handle real‑world digital cash. It implements the Model Context Protocol (MCP) for a full‑featured Cashu ecash wallet built on Nostr, allowing agents to deposit, withdraw, and tip funds directly from conversational contexts. By exposing wallet operations as MCP tools, Claude, Goose, or any MCP‑compatible client can query balances, generate Lightning invoices, and send zaps without leaving the assistant’s workflow.

The server offers a complete Cashu experience: users can add and manage multiple mints, create deposit invoices that mint providers will fund, and pay Lightning invoices using the same wallet. The integration with Nostr’s Zaps (NIP‑57) lets agents tip content creators by sending small amounts of ecash to a user’s npub or NIP‑05 identifier. All wallet state—including the private key, public key, and cached mint metadata—is persisted in a local file, ensuring quick start‑ups while keeping sensitive data on the host machine.

Key capabilities are exposed through a concise set of MCP tools:

• – total wallet balance across all mints
• – per‑mint breakdown
• – generate a Lightning invoice for a chosen mint
• – settle any Lightning invoice with the wallet’s funds
• – send a tip to another user
• – register a new Cashu mint

These commands can be invoked directly from the command line or called by an AI assistant’s prompt, enabling rich financial interactions such as “pay me a tip for that article” or “show me how much cash I have left.” Because the server runs on Bun, it remains lightweight and fast, making it suitable for deployment in edge environments or as a local helper process.

In real‑world scenarios, MCP Money is ideal for content platforms that reward creators with ecash, for AI agents that automate micro‑transactions in chat, or for developers prototyping Lightning‑enabled workflows. Its straightforward integration steps—adding a single MCP server entry in Claude Code or Goose’s config—mean that once the wallet is running, any assistant can start leveraging digital cash without custom SDKs or third‑party APIs. The combination of Nostr’s privacy‑first messaging, Cashu’s unforgeable tokens, and the MCP interface delivers a secure, modular solution that empowers developers to embed monetary interactions into AI experiences with minimal friction.