P402

P402 is an economic and routing layer designed for autonomous AI agents that need to interact with multiple large language models and services. It provides a unified interface to route AI calls across 300+ models while handling metering, payments, and settlement in the background. The primary purpose of P402 is to make it straightforward for developers to build AI-native applications that can programmatically pay for and orchestrate model usage at scale, without managing complex billing or infrastructure themselves.

Under the hood, P402 enables USDC micropayments with zero gas fees using EIP-3009, allowing off-chain authorization and on-chain settlement without requiring users to hold ETH for gas. Developers can define routing rules, pricing, and model selection logic, and P402 executes calls while tracking usage and costs per request or per agent. The platform abstracts away provider-specific billing models and exposes a consistent economic interface for AI calls, making it easier to mix and match models from different vendors. This combination of routing and payment primitives lets AI agents autonomously choose optimal models based on cost, performance, or task type.