Solana payment-channels · CHNLxYvV…hyGsX

The cap is the product.

x402 charges once per request. Agents do not. Solana Foundation shipped payment channels so a ceiling can sit in escrow, usage can move as signed vouchers, and one settle_and_seal pays what was actually consumed.

1. Open

Priya, and only Priya, calls open. Seeds are channel + payer + payee + mint + signer + salt + open_slot. The PDA is per-incarnation. Scout has no instruction for this.

2. Voucher

Exactly 50 bytes: magic 0x56 0x01, 32-byte channel id, cumulative u64 LE, expires_at i64 LE. Ed25519 over those bytes. No nonce. Replay is cumulative > watermark.

3. Merchant watermark

Kite accepts vouchers off-chain against its own accepted amount. On-chain settled stays zero until close. That is how 8 marks cost one later transaction, not eight.

4. The goods

Each hl.mark packet is BTC/ETH/SOL from Hyperliquid allMids. The brief is written from those numbers. The chain is not a sticker on a chatbot.

5. Over cap

hl.book is $8. After any spend, cumulative would exceed deposit. The program rejects before settle. The LLM does not get a vote.

6. Seal and refund

settle_and_seal then distribute. Kite receives settled. Priya receives deposit − settled. The same voucher cannot advance the watermark again.