Spawnpay

Gives Claude a USDC wallet on Base L2 with eight tools for crypto operations: signup with $5 free credit, balance checks, send/receive USDC or ETH, deposit history, and a three-tier referral system that pays 15/5/2% of platform fees. Also works as a universal payment proxy for 16 AI providers (OpenAI, Anthropic, Replicate, etc.) at $0.001 per successful request, though you bring your own API keys. The interesting bit is agent-to-agent payments using SP_ codes instead of wallet addresses, plus automatic referral tracking baked into the install config. Useful if you're building multi-agent systems that need to pay each other, want to monetize an MCP tool with per-call charges, or need consolidated billing across multiple AI services.