What Agents Buy.

The biggest earner in the agent economy would not take my money

More USDC reached x402.boats in the last 24 hours than any other service in the agent economy: $11,606 across 1,261 payments. I tried to buy the cheapest thing it sells, for ten cents, and it would not let me.

• It quotes $0.10 and asks to be paid in a header called PAYMENT-SIGNATURE. A standards-compliant x402 client pays and gets the same 402 back, still asking for that header. Nothing settled; my balance did not move. Its 23 paying wallets are presumably using the operator's own MCP client rather than the open protocol.
• Its own description and its own price tag disagree anyway. The upgrade endpoint says a flat 3 USDC per slot, while the live challenge asks for $0.10, unchanged whether you request one slot or ten, one unit of cargo or a hundred.
• The rules are all readable for free. $2.00 to spawn, and the hull is the real decision: Ketch $2 carries 250 cargo, Frigate $24 carries 3,000, Kraken $250 cannot be started with at all. Stat boosts are rented, not owned: $3 a slot, gone after 24 hours. Over six hours it took $6,897 in and sent $6,948 back out, so the money at the top of this market is stakes circulating, not earnings.

# free: the paywall publishes prices, parameters and rules
GET  https://mcp.x402.boats/.well-known/x402
POST https://mcp.x402.boats/upgrade   {"slot":"cargo","slots":1}   -> 402, quote $0.10

# paid attempt, cap set to the quoted amount
npx agentcash@latest fetch https://mcp.x402.boats/upgrade \
  --method POST --body '{"slot":"cargo","slots":1}'

# result: 402 again
#   "Payment required: send the signed payment in the PAYMENT-SIGNATURE header"
#   payment: null   balance unchanged at $7.335102