NAME

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

SYNOPSIS

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

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 must be provided if partid is non-zero, otherwise it must be equal to the final amount to the destination. By default it 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.

The payment_secret is the value that the final recipient requires to accept the payment, as defined by the payment_data field in BOLT 4 and the s field in the BOLT 11 invoice format. It is required if partid is non-zero.

The partid value, if provided and non-zero, allows for multiple parallel partial payments with the same payment_hash. The msatoshi amount (which must be provided) for each sendpay with matching payment_hash must be equal, and sendpay will fail if there are already msatoshi worth of payments pending.

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 or partid) will return immediately with success.

RETURN VALUE

On success, an object is returned, containing:

•: id (u64): unique ID for this payment attempt
•: payment_hash (hex): the hash of the payment_preimage which will prove payment (always 64 characters)
•: status (string): status of the payment (could be complete if already sent previously) (one of "pending", "complete")
•: created_at (u64): the UNIX timestamp showing when this payment was initiated
•: amount_sent_msat (msat): The amount sent
•: groupid (u64, optional): Grouping key to disambiguate multiple attempts to pay an invoice or the same payment_hash
•: amount_msat (msat, optional): The amount delivered to destination (if known)
•: destination (pubkey, optional): the final destination of the payment if known
•: label (string, optional): the label, if given to sendpay
•: partid (u64, optional): the partid, if given to sendpay
•: bolt11 (string, optional): the bolt11 string (if supplied)
•: bolt12 (string, optional): the bolt12 string (if supplied: experimental-offers only).

If status is "complete":

•: payment_preimage (hex): the proof of payment: SHA256 of this payment_hash (always 64 characters)

If status is "pending":

•: message (string): Monitor status with listpays or waitsendpay

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. In addition erring_direction will indicate which direction of the channel caused the failure.
•: 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.

RESOURCES