lightning-getroute -- Command for routing a payment (low-level) =============================================================== SYNOPSIS -------- **getroute** *id* *msatoshi* *riskfactor* \[*cltv*\] \[*fromid*\] \[*fuzzpercent*\] \[*exclude*\] \[*maxhops*\] DESCRIPTION ----------- The **getroute** RPC command attempts to find the best route for the payment of *msatoshi* to lightning node *id*, such that the payment will arrive at *id* with *cltv*-blocks to spare (default 9). *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*. There are two considerations for how good a route is: how low the fees are, and how long your payment will get stuck in a delayed output if a node goes down during the process. The *riskfactor* floating-point field controls this tradeoff; it is the annual cost of your funds being stuck (as a percentage). For example, if you thought the convenience of keeping your funds liquid (not stuck) was worth 20% per annum interest, *riskfactor* would be 20. If you didn’t care about risk, *riskfactor* would be zero. *fromid* is the node to start the route from: default is this node. The *fuzzpercent* is a positive floating-point number, representing a percentage of the actual fee. The *fuzzpercent* is used to distort computed fees along each channel, to provide some randomization to the route generated. 0.0 means the exact fee of that channel is used, while 100.0 means the fee used might be from 0 to twice the actual fee. The default is 5.0, or up to 5% fee distortion. *exclude* is a JSON array of short-channel-id/direction (e.g. \[ "564334x877x1/0", "564195x1292x0/1" \]) or node-id which should be excluded from consideration for routing. The default is not to exclude any channels or nodes. Note if the source or destination is excluded, the command result is undefined. *maxhops* is the maximum number of channels to return; default is 20. RISKFACTOR EFFECT ON ROUTING ---------------------------- The risk factor is treated as if it were an additional fee on the route, for the purposes of comparing routes. The formula used is the following approximation: risk-fee = amount x blocks-timeout x per-block-cost We are given a *riskfactor* expressed as a percentage. There are 52596 blocks per year, thus *per-block-cost* is *riskfactor* divided by 5,259,600. The final result is: risk-fee = amount x blocks-timeout x riskfactor / 5259600 Here are the risk fees in millisatoshis, using various parameters. I assume a channel charges the default of 1000 millisatoshis plus 1 part-per-million. Common to\_self\_delay values on the network at 14 and 144 blocks.
Amount (msat) Riskfactor Delay Risk Fee Route fee

10,000

1

14

0

1001

10,000

10

14

0

1001

10,000

100

14

2

1001

10,000

1000

14

26

1001

1,000,000

1

14

2

1001

1,000,000

10

14

26

1001

1,000,000

100

14

266

1001

1,000,000

1000

14

2661

1001

100,000,000

1

14

266

1100

100,000,000

10

14

2661

1100

100,000,000

100

14

26617

1100

100,000,000

1000

14

266179

1100

10,000

1

144

0

1001

10,000

10

144

2

1001

10,000

100

144

27

1001

10,000

1000

144

273

1001

1,000,000

1

144

27

1001

1,000,000

10

144

273

1001

1,000,000

100

144

2737

1001

1,000,000

1000

144

27378

1001

100,000,000

1

144

2737

1100

100,000,000

10

144

27378

1100

100,000,000

100

144

273785

1100

100,000,000

1000

144

2737850

1100

RECOMMENDED RISKFACTOR VALUES ----------------------------- The default *fuzz* factor is 5%, so as you can see from the table above, that tends to overwhelm the effect of *riskfactor* less than about 5. 1 is a conservative value for a stable lightning network with very few failures. 1000 is an aggressive value for trying to minimize timeouts at all costs. The default for lightning-pay(7) is 10, which starts to become a major factor for larger amounts, and is basically ignored for tiny ones. RETURN VALUE ------------ On success, a "route" array is returned. Each array element contains *id* (the node being routed through), *msatoshi* (the millisatoshis sent), *amount\_msat* (the same, with *msat* appended), *delay* (the number of blocks to timeout at this node), and *style* (indicating the features which can be used for this hop). The final *id* will be the destination *id* given in the input. The difference between the first *msatoshi* minus the *msatoshi* given in the input is the fee. The first *delay* is the very worst case timeout for the payment failure, in blocks. AUTHOR ------ Rusty Russell <> is mainly responsible. SEE ALSO -------- lightning-pay(7), lightning-sendpay(7). RESOURCES --------- Main web site: