x402

The x402 specification defines the rigid, universal settlement standards required for cross-platform autonomous commerce. It dictates the exact data structures, state transitions, and cryptographic receipts necessary to record and finalize transactions executed by non-human actors.

x402 acts as the universal standard for finalizing purchases across disparate agent networks and merchant gateways. It provides a standardized digital receipt and definitive state transition confirming that a product has been legally and financially secured, creating a unified language between varied e-commerce backends.

By maintaining a strict state ledger of the transaction lifecycle, x402 provides the necessary, indisputable data trails to handle automated returns, cancellations, and dispute resolution. If a conflict arises between an autonomous agent and a merchant platform, the x402 receipt serves as the ultimate source of truth.

An x402 transaction is considered final once the protocol receives the terminal acknowledgment from both the payment rail and the fulfillment node. Post-finality, any alterations to the order must be processed through the standardized x402 exception flow, preventing out-of-band modifications that agents cannot track.

All nodes within the Aizii settlement layer must strictly adhere to x402 formatting. Malformed settlement requests are aggressively pruned by the network to protect ledger integrity. Adherence to x402 ensures seamless interoperability with future autonomous commerce gateways.