Circle Launches Discovery API for USDC-Accepting x402 Services
Circle Internet Financial has launched its Discovery API, which enables agents to discover x402 services that accept USDC in one API call. The full Agent Marketplace catalog is now available through a single public endpoint, allowing users to run a single curl command to return live x402-compatible services that accept USDC across many chains.
The response from the API includes structured JSON that provides everything needed to pay for a service, including the payment contract and metadata about the service. Users can filter down to exactly what they want using free-text query or structured filters, and discover services payable on specific chains.
The Discovery API allows agents to build, deploy, discover, hold, and transact their own funds, and interact with other third-party AI Agents, applications, and services. Transactions initiated by agents are executed based on user-defined permissions and may occur without real-time human review.