Circle, the issuer of the USDC stablecoin, has introduced a new discovery layer within its Agent Stack that lets AI agents automatically find and pay for digital services, building on a marketplace that already lists more than 900 endpoints for agentic services. The Discovery API gives builders programmatic access to Circle’s Agent Marketplace catalogue through a single public endpoint, letting an agent query for services by category, blockchain, and pricing, then call the endpoint directly via HTTP without prior registration or an API key. When a service is called, the server responds with an HTTP 402 Payment Required status containing a machine-readable payload specifying price and payment destination; the agent’s wallet cryptographically signs a payment authorization, a facilitator verifies and settles the USDC transaction on-chain, and the service delivers its output. The main objective is to establish USDC and the x402 protocol as a settlement layer for machine-to-machine commerce, letting individuals deploy a single AI assistant with a funded wallet to manage subscriptions, on-demand computing, and pay-per-inference AI access on a pay-per-request basis, with risk controlled through isolated agent wallets, per-transaction caps, and circuit breakers that revoke signing permissions if unusual payment activity is detected. Key players include Circle, which built the system atop its Developer-Controlled Wallets using multi-party computation to keep master seed phrases inaccessible to agents, positioning the launch as part of a broader industry push to define payment standards for AI-driven commerce.

Circle Launches Agent Discovery Layer to Let AI Agents Pay With USDC