Get payment challenge

Retrieve a payment's original MPP or L402 challenge without creating another invoice.

GET/gateway/payments/{id}/challenge

Required permission: Gateway → Read.

Path parameters

idstringRequired: Payment ID returned by Create a payment. Use the same ID for status checks, challenge retrieval and credential validation.

Errors

Status	Code	What to do
`401`	`unauthorized`	Check your API key and Gateway → Read permission.
`404`	`gateway_payment_not_found`	Use a payment ID created in the key's account.
`410`	`payment_expired`	Request a new payment if the unpaid challenge has expired.

See Error handling for other errors.

Request

Use the payment ID returned when creating the payment.

curl "https://api.nodana.io/v1/gateway/payments/payment-123/challenge" \
  -H "Authorization: Bearer YOUR_API_KEY"

Response

{
  "id": "payment-123",
  "protocol": "mpp",
  "status": "payment_required",
  "challenge": "<MPP challenge returned by Nodana>"
}

For L402, protocol is l402 and challenge contains the L402 macaroon and invoice header value.

Return HTTP 402 to the calling client with WWW-Authenticate set to challenge. Retrieving a challenge does not validate a payment; use Validate a payment when the client supplies its credential.