Coal — Payments for AI agents

Adds USDC payment rails on Base directly to Claude Desktop. Exposes merchant discovery, checkout session creation, payment verification, and receipt lookups through a multi-tenant MCP endpoint. Implements dual-protocol agent payments: Coinbase x402 paywalls and OKX APP envelopes hit the same verification route. Payment receipts get published to 0G Storage and anchored on-chain with proof hashes. The server wraps Coal's hosted checkout API, so agents can initiate purchases, poll transaction status, and retrieve verifiable receipts without leaving the MCP context. Useful when you want Claude to autonomously pay for digital goods, query merchant catalogs, or build commerce workflows that settle in stablecoins.