zk402 is a next-generation privacy protocol designed to bring confidential, verifiable, and seamless on-chain transactions to the broader blockchain ecosystem. The project was created to combine zero-knowledge cryptography with the x402 payment infrastructure, forming a system where users can transact freely without revealing sensitive information while maintaining full on-chain validity. Today, most blockchain transactions are fully transparent and easily traced, which exposes financial data and limits privacy. zk402 is built to solve this problem by providing a privacy layer that protects users and businesses while keeping transactions trustless and verifiable. The core of zk402 enables private and secure transfers across more than 2800 supported coins and tokens. This allows users to transact using the assets they already hold while ensuring that the transaction amounts, sender, and receiver details are hidden using zero-knowledge proofs. Even though transaction details are shielded, all transactions remain verifiable on-chain, offering a balance between confidentiality and transparency. This design makes zk402 suitable for personal financial protection, business payments, and decentralized applications that require privacy without compromising compliance. For developers, zk402 offers an SDK and API that simplify the integration of privacy features into any application. The SDK is designed to be lightweight, efficient, and compatible with existing workflows, allowing developers to add private transfers, confidential balances, and secure interactions without needing advanced cryptographic knowledge. This makes zk402 a practical solution for wallets, fintech apps, payment platforms, and decentralized services that want to offer private payment capabilities to their users. By abstracting the complexity of zero-knowledge technology, zk402 enables more builders to adopt privacy features quickly. The project is also developing a Facilitator Network, an infrastructure layer that ensures high-availability operations for private transactions. Facilitators help process, verify, and maintain uptime for zk402 transactions, making the protocol reliable for real-world payment activity. In the next phase, zk402 will introduce Facilitator Incentives, giving users and token holders an opportunity to participate in securing and supporting the network through a reward-based system. Overall, zk402 is focused on enabling the evolution of blockchain payments: private, secure, fast, and compatible with thousands of assets. It delivers the privacy users deserve while maintaining the usability and verification required in Web3. By merging zero-knowledge cryptography with the proven speed and reliability of x402, zk402 aims to become the standard for privacy-preserving payments and set the foundation for wider adoption of private digital transactions across the blockchain industry.