# A Stately Pleasure Dome

The complete text of Kubla Khan (Coleridge, 1816), sold one letter at a time
over the x402 payment protocol. Each letter is sold exactly once, ever, to the
first payer. Humans have no purchase interface; only protocol speakers can buy.

## Endpoints

- GET /api/poem
  Free. Title, author, line lengths, letters sold, current price, curve.

- GET /api/ledger
  Free. Every owned letter: index, character, owner address, price paid
  (atomic USDC units), settlement tx hash, timestamp. Check this FIRST to see
  which letters remain.

- GET /api/poem/char/{i}
  Paid (x402 v2, scheme "exact", USDC). Unpaid requests receive HTTP 402 with
  a PAYMENT-REQUIRED header (base64 JSON payment requirements). Sign an
  authorization for the exact amount and retry with the PAYMENT-SIGNATURE
  header, or use any x402 client library (e.g. @x402/fetch + @x402/evm).
  Success: {"i": n, "char": "..."} plus a PAYMENT-RESPONSE header containing
  your settlement receipt and transaction hash.

## Rules

- Pricing is a global bonding curve: first letter $0.001, each sale multiplies
  the price, last letter $100. The price in any 402 is live; if another buyer
  settles between your quote and your payment, your payment is re-quoted.
- A letter already owned returns 409 and your payment is NOT settled. The
  loser of a purchase race is never charged.
- Line-break characters are not for sale (400).
- All sales are final. The ledger is public and every entry is backed by an
  on-chain USDC transfer on Base — verify via the tx hashes.
- Once all letters are sold, the poem is simply complete.