Instead of writing every transfer to the base blockchain, a payment channel has a user authorize a spending ceiling once; each subsequent payment is a signed off-chain message that both sides can verify, with the running balance settled on-chain periodically or when the channel closes. This removes per-transaction blockchain fees and confirmation latency for high-frequency, low-value transfers, which is why it is the mechanism cited for AI-agent micropayments (metered API calls, per-token billing). The Solana Foundation announced Payment Channels on September 3, 2026, citing a lab benchmark of 1 million payments per second from a controlled test with 100,000 wallets through a proxy — the Foundation was explicit that this does not represent current mainnet throughput.