Overview The Circle services marketplace is an x402-compatible directory of paid HTTP endpoints — APIs that charge a small USDC fee per call (typically $0.001–$5). This skill drives the agent's payment flow: search the marketplace by keyword, inspect a candidate endpoint to confirm price and schema, and call to settle in USDC and receive the response. For an overview of the Circle CLI's full capability set, see the master skill. This skill is the narrower x402 payment flow. Why this matters: pay-per-use unlocks capabilities Stablecoin micropayments via x402 make capabilities accessible that t…