visitor@x402card:~$ explain flow
How x402card works
x402card offers two independent x402 flows. A wallet owner can issue and fund a virtual card, or an x402 payer can buy a prepaid Freeland travel eSIM and receive its installation credentials privately.
Last verified against production architecture: 2026-08-18.
The complete flow
- Public purchase challenge. An agent POSTs one stable idempotency key to
/api/card/purchaseand validates the returned exact Base-USDC 402 requirements. - Payer ownership. The agent repeats the same request once with
PAYMENT-SIGNATURE. The payer becomes the owner; no bearer session is required for purchase. - Issue economics. The wallet pays exactly 25 USDC. VALUT issues a $25 card, then an idempotent $10 withdrawal returns the platform fee to the master balance, leaving $15 expected.
- Private continuation. The payer wallet authenticates afterward to read owner state. Card credentials require a separate fresh signature and are never returned by the purchase route or remote MCP.
- Payable URL. The owner creates an order. The returned URL answers with HTTP
402 Payment Requiredand exact Base-USDC payment requirements. - Settlement. A payer agent signs the payment and retries the same URL. The facilitator verifies and settles it on Base.
- Materialization. x402card stores durable settlement evidence exactly once. Ambiguous provider results are not treated as success.
- Card funding. A worker uses the pre-funded provider USD float to top up the card. Received Base-USDC remains treasury inventory until operator rebalancing.
The eSIM flow
- Choose. Read the live Freeland catalog and select a destination, data allowance, duration, and exact current price.
- Prepare. POST the plan id and one stable idempotency key to the public purchase route and inspect its HTTP 402 requirements.
- Pay once. Settle the exact quote in native USDC on Base. The x402 payer becomes the owner; no card is required.
- Fulfill. Preserve the private order delivery token and poll the same order while the eSIM is allocated.
- Install. Retrieve the owner-only ICCID, QR/LPA data, and installation links with a private, non-cacheable response.
Settlement is not the same as card credit
settled
The USDC payment has authoritative settlement evidence.
funding
A separate idempotent provider job is processing the card top-up.
funded
The provider has confirmed the card funding result.
operator review
An ambiguous or delayed state is held for safe review instead of being replayed blindly.
Current payment rail
- Protocol: x402 v2 exact payment
- Network: Base mainnet,
eip155:8453 - Asset: native USDC on Base
- Card provider: VALUT
- Treasury rebalancing: manual
For machine-readable discovery, see the agent contract, OpenAPI, and the well-known agent descriptor.