The \fBinvoice\fR RPC command creates the expectation of a payment of a given amount of milli\-satoshi: it returns a unique token which another lightning daemon can use to pay this invoice\&. This token includes a \fIroute hint\fR description of an incoming channel with capacity to pay the invoice, if any exists\&.
The \fImsatoshi\fR parameter can be the string "any", which creates an invoice that can be paid with any amount\&. Otherwise it is in millisatoshi precision; it can be a whole number, or a whole number ending in \fImsat\fR or \fIsat\fR, or a number with three decimal places ending in \fIsat\fR, or a number with 1 to 11 decimal places ending in \fIbtc\fR\&.
The \fIlabel\fR must be a unique string or number (which is treated as a string, so "01" is different from "1"); it is never revealed to other nodes on the lightning network, but it can be used to query the status of this invoice\&.
The \fIdescription\fR is a short description of purpose of payment, e\&.g\&. \fI1 cup of coffee\fR\&. This value is encoded into the BOLT11 invoice and is viewable by any node you send this invoice to\&. It must be UTF\-8, and cannot use \fI\eu\fR JSON escape codes\&.
The \fIexpiry\fR is optionally the time the invoice is valid for; without a suffix it is interpreted as seconds, otherwise suffixes \fIs\fR, \fIm\fR, \fIh\fR, \fId\fR, \fIw\fR indicate seconds, minutes, hours, days and weeks respectively\&. If no value is provided the default of 604800 (1w) is used\&.
The \fIfallbacks\fR array is one or more fallback addresses to include in the invoice (in order from most\-preferred to least): note that these arrays are not currently tracked to fulfill the invoice\&.
The \fIpreimage\fR is a 64\-digit hex string to be used as payment preimage for the created invoice\&. By default, if unspecified, lightningd will generate a secure pseudorandom preimage seeded from an appropriate entropy source on your system\&. \fBIMPORTANT\fR: if you specify the \fIpreimage\fR, you are responsible, to ensure appropriate care for generating using a secure pseudorandom generator seeded with sufficient entropy, and keeping the preimage secret\&. This parameter is an advanced feature intended for use with cutting\-edge cryptographic protocols and should not be used unless explicitly needed\&.
If specified, \fIexposeprivatechannels\fR overrides the default route hint logic, which will use unpublished channels only if there are no published channels\&. If \fItrue\fR unpublished channels are always considered as a route hint candidate; if \fIfalse\fR, never\&.
The route hint is selected from the set of incoming channels of which: peer\(cqs balance minus their reserves is at least \fImsatoshi\fR, state is normal, the peer is connected and not a dead end (i\&.e\&. has at least one other public channel)\&. The selection uses some randomness to prevent probing, but favors channels that become more balanced after the payment\&.
On success, a hash is returned as \fIpayment_hash\fR to be given to the payer, and the \fIexpiry_time\fR as a UNIX timestamp\&. It also returns a BOLT11 invoice as \fIbolt11\fR to be given to the payer\&.
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On failure, an error is returned and no invoice is created\&. If the lightning process fails before responding, the caller should use lightning\-listinvoice(7) to query whether this invoice was created or not\&.