Swaps

See the guide for the full flow.

List assets

GET /v1/swap/assets

Auth: none. Lunaz caches the list for 5 minutes.

[
  {
    "asset_id": "nep141:usdc.example",
    "symbol": "USDC",
    "blockchain": "eth",
    "decimals": 6,
    "price_usd": 1.0
  }
]

Start a swap

POST /v1/invoices/{id}/swap

Auth: none. The invoice ID is the access token.

Field	Type	Notes
`asset_id`	string	An `asset_id` from the asset list.
`refund_to`	string	The buyer’s refund address on the origin chain.

{
  "swap_id": "5d7c0e2a-9a41-4c3e-8d1f-2b6a7e90c4d3",
  "deposit_address": "0xExampleDepositAddress0000000000000000000",
  "deposit_memo": null,
  "amount_in": "3520000",
  "amount_in_formatted": "3.52",
  "amount_in_usd": "3.52",
  "symbol": "USDC",
  "blockchain": "eth",
  "deadline": "2026-10-13T12:30:00Z",
  "time_estimate": 120
}

The quote is exact-output for the invoice amount. The 1Click fee is added to amount_in. The deadline is the invoice expiry, or 30 minutes from now if that is earlier. The minimum invoice for a swap is approximately 100000 zat.

A new request replaces the old swap. The old deposit address is abandoned.

Errors:

Status	Message	Cause
400	`refund_to required`	The refund address is empty.
400	`unsupported asset_id`	The asset is not in the list.
400	1Click message	1Click rejected the quote, for example for a bad refund address or an amount below the minimum.
404	`no such invoice`	Unknown invoice.
409	`invoice is not pending`	The invoice is not `pending` or has expired.
409	`a swap is already in progress (...)`	1Click already saw a deposit.
429	`too many swap requests, try again later`	More than 5 requests for one invoice in 10 minutes.
502	`swap provider unavailable`	1Click did not answer.