Bitcoin Lightning Network #3: Paying for goods and services

There’s at least one dice site using Lightning Network payments, Lightning Spin.

I click the Spin button.

Lightning Spin is glitching. The payment invoice is changing rapidly. I restart my browser and try again.

This time the payment request remains stable. I look in the lncli help to see how I can send funds.

There are plenty of routes available, at least ten. I use decodepayreq to see what the Lightning Network payment invoice actually contains.

ubuntu@ip-172-31-33-128:~$ lncli decodepayreq lnbc1m1pd5xfe7pp56spv65p5sr52q8gax8ugkxqj838waadn9qrm7kmdxck3366px4pqdqlf35kw6r5de5kueeq2dcxjm3q95sr27qcqzysmdfw5q5w6npkg7ashyjfqr5qcszdrua0shxq8nzvxq9ee2leucrk5mxjp4tzkkhexgha34dqdsf6ujxd02tjx8f94uzps8nl09apxdgqpmczyv
{
    "destination": "02cf3cc45d8fee5055c4ba5a58fe22ae973685fa2cb43e2c5b6454eaa1d08066a8",
    "payment_hash": "d402cd503480e8a01d1d31f88b18123c4eeef5b32807bf5b6d362d18eb413542",
    "num_satoshis": "100000",
    "timestamp": "1531127614",
    "expiry": "3600",
    "description": "Lightning Spin - 5x",
    "description_hash": "",
    "fallback_addr": "",
    "cltv_expiry": "144",
    "route_hints": [
    ]
}

The amount and node identifier are correct. I run the lncli payinvoice command.

ubuntu@ip-172-31-33-128:~$ lncli payinvoice lnbc1m1pd5xfe7pp56spv65p5sr52q8gax8ugkxqj838waadn9qrm7kmdxck3366px4pqdqlf35kw6r5de5kueeq2dcxjm3q95sr27qcqzysmdfw5q5w6npkg7ashyjfqr5qcszdrua0shxq8nzvxq9ee2leucrk5mxjp4tzkkhexgha34dqdsf6ujxd02tjx8f94uzps8nl09apxdgqpmczyv
{
        "payment_error": "",
        "payment_preimage": "a135dcd537912d68ebcc064cded992ad2ca73a07181c6e41dfc18cb7f057c14a",
        "payment_route": {
                "total_time_lock": 531322,
                "total_fees": 1,
                "total_amt": 100001,
                "hops": [
                        {
                                "chan_id": 583927535793471488,
                                "chan_capacity": 326943,
                                "amt_to_forward": 100000,
                                "fee": 1,
                                "expiry": 531308,
                                "amt_to_forward_msat": 100000000,
                                "fee_msat": 1800
                        },
                        {
                                "chan_id": 582182610938953728,
                                "chan_capacity": 1337000,
                                "amt_to_forward": 100000,
                                "expiry": 531308,
                                "amt_to_forward_msat": 100000000
                        }
                ],
                "total_fees_msat": 1800,
                "total_amt_msat": 100001800
        }
}

The payment will be sent through two hops and pay 1800 msats (0.00000002 BTC or 0.000135 USD).

Back in the web browser the spin has been detected and I have won 400,000 sats (0.004 BTC or $30 USD)!

I click Withdraw.

I must create a Lightning Network payment invoice for 500,000 satoshis. I consult the lncli help.

$ lncli -h | grep inv
     payinvoice     Pay an invoice over lightning.
     addinvoice     Add a new invoice.
     lookupinvoice  Lookup an existing invoice by its payment hash.
     listinvoices   List all invoices currently stored.

The addinvoice command looks like what I need.

The command has a lot of parameters. I start to experiment.

$ lncli addinvoice --amt 500000
{
        "r_hash": "8a6c89724b806dfa085400e25c47ac98059048f4feb3509db6072c05dac3b2b7",
        "pay_req": "lnbc5m1pd5x2uspp53fkgjujtspkl5zz5qr39c3avnqzeqj85l6e4p8dkqukqtkkrk2msdqqcqzys2s48rrh22ff0rvj8sl6rdx4adrmhw2pxemrnt0skckzmczg5ndp39h972przrlqg4ng0v7aw29hzr5w0a9kka7nfs3385q303tsmzrcphc5tre"
}

Easy enough. I paste the pay_req string into Lightning Spin.

The website claims the payment has been sent! I return to lncli to check the status.

The payment has been received and settled! I’m not entirely sure what that means, but I’ll assume it’s safe.

While I’ve been enjoying gambling, lnd is still opening channels and approaching 100 channels. I add some more zeroes to the fee settings and restart lnd.

The settings are bitcoin.basefee=100000000 and bitcoin.feerate=100000.

Satoshi’s Place

Satohi’s Place is a clone of the million dollar homepage. Ppixels are bought using Lightning Network payments. I decide to repeat my tank man stunt.

Blake, the Chief Meme Officer of Shitcoin.com quickly designs a 1000x800 pixel version.

I find a tool that converts uploaded images to Lightning Network invoices to paint pixels on Satoshi’s Place.

I decide to pay all eight invoices in one command.

The first few Lightning invoices pay quickly and the image starts appearing on Satoshi’s Place.

The bottom of the picture never appears. Back in lncli there are several error messages.

I retry the invoice corresponding to the bottom right of the image. The TemporaryChannelFailure has become a permanent channel failure. I restart lnd, which as this point must be terminated with the kill command as opposed to stopping normally.

I ask on the Lightning Network Slack chat. They recommend I establish channels manually to Satoshi’s Place or to users that have channels to Satoshi’s Place.

I take a few hours break to have dinner with some friends.