lightning-sendpay – Low-level command for sending a payment via a route

SYNOPSIS

sendpay route payment_hash [label] [msatoshi] [bolt11]

DESCRIPTION

The sendpay RPC command attempts to send funds associated with the given payment_hash, along a route to the final destination in the route.

Generally, a client would call lightning-getroute(7) to resolve a route, then use sendpay to send it. If it fails, it would call lightning-getroute(7) again to retry.

The response will occur when the payment is on its way to the destination. The sendpay RPC command does not wait for definite success or definite failure of the payment. Instead, use the waitsendpay RPC command to poll or wait for definite success or definite failure.

The label and bolt11 parameters, if provided, will be returned in waitsendpay and listsendpays results.

The msatoshi amount, if provided, is the amount that will be recorded as the target payment value. If not specified, it will be the final amount to the destination. If specified, then the final amount at the destination must be from the specified msatoshi to twice the specified msatoshi, inclusive. This is intended to obscure payments by overpaying slightly at the destination; the actual target payment is what should be specified as the msatoshi argument. msatoshi is in millisatoshi precision; it can be a whole number, or a whole number ending in msat or sat, or a number with three decimal places ending in sat, or a number with 1 to 11 decimal places ending in btc.

Once a payment has succeeded, calls to sendpay with the same payment_hash but a different msatoshi or destination will fail; this prevents accidental multiple payments. Calls to sendpay with the same payment_hash, msatoshi, and destination as a previous successful payment (even if a different route) will return immediately with success.

RETURN VALUE

On success, an object similar to the output of listsendpays will be returned. This object will have a status field that is typically the string “pending”, but may be “complete” if the payment was already performed successfully.

On error, if the error occurred from a node other than the final destination, the route table will be updated so that lightning-getroute(7) should return an alternate route (if any). An error from the final destination implies the payment should not be retried.

The following error codes may occur:

  • -1: Catchall nonspecific error.
  • 201: Already paid with this hash using different amount or destination.
  • 202: Unparseable onion reply. The data field of the error will have an onionreply field, a hex string representation of the raw onion reply.
  • 203: Permanent failure at destination. The data field of the error will be routing failure object.
  • 204: Failure along route; retry a different route. The data field of the error will be routing failure object.

A routing failure object has the fields below:

  • erring_index. The index of the node along the route that reported the error. 0 for the local node, 1 for the first hop, and so on.
  • erring_node. The hex string of the pubkey id of the node that reported the error.
  • erring_channel. The short channel ID of the channel that has the error, or 0:0:0 if the destination node raised the error.
  • failcode. The failure code, as per BOLT #4.
  • channel_update. The hex string of the channel_update message received from the remote node. Only present if error is from the remote node and the failcode has the UPDATE bit set, as per BOLT #4.

AUTHOR

Rusty Russell <rusty@rustcorp.com.au> is mainly responsible.

SEE ALSO

lightning-listinvoice(7), lightning-delinvoice(7), lightning-getroute(7), lightning-invoice(7), lightning-pay(7), lightning-waitsendpay(7).