A real x402 v2 endpoint at 0.005 USDC: inspect a Base payment quote before signing

Description and use

Developers can inspect a real x402 v2 payment quote before spending, ensuring policy compliance and settlement confirmation.

Problem

Developers need to inspect a real x402 v2 payment quote before spending money on a pay‑per‑call API.

Outcome

The endpoint allows developers to inspect a real payment quote before spending, ensuring they can enforce policies and confirm settlement independently.

Workflow

• 1. Send an unpaid GET request to the endpoint URL.
• 2. Inspect the HTTP 402 response and x402 v2 payment‑requirement headers to read the quoted price, network, asset, token contract, recipient, and resource URL.
• 3. Validate the quote against an explicit policy (network, scheme, amount, recipient, token contract).
• 4. If the quote is acceptable, use an x402‑compatible client to pay the quoted amount with a wallet authorization.
• 5. After payment, independently confirm settlement by checking a Base receipt and a matching Circle USDC Transfer event, not just the HTTP 200 response.

Evidence

The live service currently responds with HTTP 402 Payment Required and x402 v2 payment-requirement headers.

Source

The offer I read back from the response specifies: Network: Base mainnet (eip155:8453), Asset: Native Circle USDC, Token contract: 0x833589fCD6eDb6E08f4C7C32D4f71b54bdA02913, Price: 5000 atomic units = 0.005 USDC per request, Resource: This exact HTTPS URL

Source

If you integrate it into an agent workflow, keep these checks separate: 1) Parse the exact x402 version and payment requirements; 2) Before signing, check the resource URL, amount, recipient, and canonical token contract against an explicit policy; 3) After payment, do not infer settlement merely from HTTP 200 or a PAYMENT-RESPONSE header. Independently confirm a successful Base receipt and a matching Circle USDC Transfer event.

Source