# x402card

x402card is a wallet-native crypto card. Wallet signatures authenticate owners. Incoming x402 payments settle USDC on Base and automatically create card-funding jobs.

Agent rule:
- Do not open or browse the human root website for service work.
- Use MCP first: https://api.x402card.org/mcp
- If MCP is unavailable, use the HTTP API contract below.

Primary agent docs:
- MCP endpoint: https://api.x402card.org/mcp
- Machine-readable API contract: https://api.x402card.org/api/agent
- OpenAPI: https://api.x402card.org/api/openapi.json
- Well-known agent JSON: https://api.x402card.org/.well-known/agent.json
- Human-readable hidden docs: https://x402card.org/agent.html
- Runtime config: https://api.x402card.org/api/config
- Readiness: https://api.x402card.org/ready
- Install CLI: curl -sSL https://x402card.org/install | sh

API base:
- https://api.x402card.org

CLI:
- x402card mcp
- x402card api
- x402card openapi
- x402card status

Core owner-agent flow:
1. POST /api/auth/challenge { address }
2. Sign returned message with the EVM wallet.
3. POST /api/auth/verify { address, message, signature }
4. Use Authorization: Bearer <token>
5. GET /api/cards or POST /api/cards
6. POST /api/orders { amount }
7. Share returned payable_url with a payer agent.

Core payer-agent flow:
1. Request payable_url.
2. Read HTTP 402 and PAYMENT-REQUIRED.
3. Build x402 exact EVM payment on Base USDC.
4. Retry same URL with PAYMENT-SIGNATURE.
5. Read PAYMENT-RESPONSE and JSON funding result.

x402:
- version: 2
- scheme: exact
- network: eip155:8453
- asset: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
- public payable endpoint: GET|POST https://api.x402card.org/pay/:orderId

Constraints:
- No app balance.
- Active card required before order creation.
- Minimum order is currently $25.
- Card funding is automatic after confirmed x402 settlement.
- VALUT card top-up uses pre-funded VALUT float; Base-USDC treasury rebalance is manual.