Credpay Checkout Skill

API Base URL: https://checkout-agent.credpay.xyz

Trigger this skill whenever the user wants to purchase, order, or checkout a product from any online store.

What you need from the user

Collect these before starting (ask if missing):

Field Example

Product URL https://example.com/products/tee

Quantity 1

Size / Color (if applicable) "Size": "M", "Color": "Black"

Email customer@example.com

Goods total (USD) "49.99" — item price as a USD string, no currency symbol

Shipping address firstName, lastName, line1, city, state, postalCode, country, phone

Step 1 — Get a quote (no payment needed)

POST https://checkout-agent.credpay.xyz/v1/quote Content-Type: application/json

{ "items": [ { "url": "<product URL>", "quantity": 1, "options": { "Size": "M", "Color": "Black" } } ], "email": "<email>", "shippingAddress": { "firstName": "Jane", "lastName": "Doe", "line1": "123 Main St", "city": "Austin", "state": "TX", "postalCode": "78701", "country": "United States", "countryCode": "US", "phone": "+15125551234" }, "goodsTotal": "<item price in USD as string, e.g. "49.99">" }

→ Save maxAmount from the response. This is the USDC amount you will pay via x402.

Step 2 — Submit checkout (x402 payment required)

POST https://checkout-agent.credpay.xyz/v1/checkout Content-Type: application/json X-PAYMENT: <x402 payment payload for maxAmount on Base chainId 8453>

<same body as Step 1>

→ On 202 : save requestId and go to Step 3. → On 402 : re-read the payment requirements from the response and retry with a correct X-PAYMENT header.

Step 3 — Poll for completion

GET https://checkout-agent.credpay.xyz/v1/checkout/{requestId}

Poll every 5 seconds. Stop when status is completed or failed . Timeout after 10 minutes.

Status Action

processing

Keep polling

authorization_required

See Step 4

completed

Done — return result to user

failed

Report errorCode

• errorMessage to user

Step 4 — Handle extra payment (if needed)

If status is authorization_required , the order total exceeded the quoted amount:

POST https://checkout-agent.credpay.xyz/v1/checkout/{requestId}/authorize X-PAYMENT: <x402 payment for extraOwed amount>

Then resume polling from Step 3.

Rules

• Works with any online store — just pass the product page URL.

• Never create a second checkout for the same intent while a requestId is active.

• Retry transient network errors with exponential backoff. Never blind-retry failed status.

• Default chainId is 8453 (Base).

Success response

{ "requestId": "req_abc123", "status": "completed", "success": true, "orderNumber": "1234" }

Failure response

{ "requestId": "req_abc123", "status": "failed", "success": false, "errorCode": "payment_failed", "errorMessage": "Card declined" }