core-lightning/doc/lightningd.8.txt

LIGHTNINGD(8)
=============
:doctype: manpage

NAME
----
lightningd - Daemon for running a Lightning Network node

SYNOPSIS
--------
lightningd [--conf=<config-file>] ['OPTIONS']...

DESCRIPTION
-----------
*lightningd* starts the C-Lightning daemon, which implements a
standards-compliant Lightning Network node.

CONFIGURATION OPTIONS
---------------------
*--conf*='FILE'::
  Specify configuration file.
  If not an absolute path, will be relative from the lightning-dir
  location.
  Defaults to 'config'.
*--lightning-dir*='DIR'::
  Set the directory for the C-Lightning daemon.
  Defaults to '$HOME/.lightning'.

MORE OPTIONS
------------
Command line options are mirrored as configuration options in the
configuration file, so 'foo' in the configuration file simply
becomes '--foo' on the command line, and 'foo=bar' becomes
'--foo=bar'.

See lightningd-config(5) for a comprehensive list of all
available options.

LOGGING AND COMMANDING C-LIGHTNING
-----------------------------
By default, C-Lightning will log to the standard output.
To log to a specific file, use '--log-file=PATH'.
Sending SIGHUP will cause C-Lightning to reopen this file,
for example to do log rotation.

C-Lightning will set up a Unix domain socket for receiving
commands.
By default this will be the file 'lightning-rpc' in your
specified 'lightning-dir'.
You can use lightning-cli(1) to send commands to C-Lightning
once 'lightningd' has started; you need to match the
'--lightning-dir' and '--rpc-file' options between them.

Commands for C-Lightning are described in various manpages
in section 7, with the common prefix 'lightning-'.

QUICK START
-----------
First, decide on and create a directory for 'lightning-dir',
or just use the default '$HOME/.lightning'.
Then create a 'config' file in this directory containing your
configuration.

Your other main preparation would be to set up a mainnet Bitcoin
fullnode, i.e. run a bitcoind(1) instance.
The rest of this quick start guide will assume you are reckless
and want to spend real funds on Lightning.
Indicate 'network=bitcoin' in your 'config' file explicitly.

C-Lightning needs to communicate with the Bitcoin Core RPC.
You can set this up using 'bitcoin-datadir', 'bitcoin-rpcconnect',
'bitcoin-rpcport', 'bitcoin-rpcuser', and 'bitcoin-rpcpassword'
options in your 'config' file.

Finally, just to keep yourself sane, decide on a log file name
and indicate it using 'log-file=lightningd.log' in your 'config' file.
You might be interested in viewing it periodically as you follow
along on this guide.

Once the *bitcoind* instance is running, start lightningd(8):

  $ lightningd --lightning-dir=$HOME/.lightning --daemon

This starts *lightningd* in the background due to the '--daemon'
option.

Check if things are working:

  $ lightning-cli --lightning-dir=%HOME/.lightning help
  $ lightning-cli --lightning-dir=%HOME/.lightning getinfo

The *getinfo* command in particular will return a 'blockheight'
field, which indicates the block height to which *lightningd*
has been synchronized to (this is separate from the block height
that your *bitcoind* has been synchronized to, and will always
lag behind *bitcoind*).
You will have to wait until the 'blockheight' has reached the
actual blockheight of the Bitcoin network.

Before you can get funds offchain, you need to have some funds
onchain owned by *lightningd* (which has a separate wallet from
the *bitcoind* it connects to).
Get an address for *lightningd* via lightning-newaddr(7) command
as below ('--lightning-dir' option has been elided, specify it if
you selected your own 'lightning-dir'):

  $ lightning-cli newaddr

This will provide a native SegWit bech32 address.
In case all your money is in services that do not support native
SegWit and have to use P2SH-wrapped addresses, instead use:

  $ lightning-cli newaddr p2sh-segwit

Transfer a small amount of onchain funds to the given address.
Check the status of all your funds (onchain and on-Lightning) via
lightning-listfunds(7):

  $ lightning-cli listfunds

Now you need to look for an arbitrary Lightning node to connect to,
which you can do by using dig(1) and querying 'lseed.bitcoinstats.com':

  $ dig lseed.bitcoinstats.com A

This will give 25 IPv4 addresses, you can select any one of those.
You will also need to learn the corresponding public key, which you can
determine by searching the IP addrss on https://1ml.com/ .
The public key is a long hex string, like so:
'024772ee4fa461febcef09d5869e1238f932861f57be7a6633048514e3f56644a1'.
(this example public key is not used as of this writing)

After determining a public key, use lightning-connect(7) to
connect to that public key:

  $ lightning-cli connect $PUBLICKEY

Then open a channel to that node using lightning-fundchannel(7):

  $ lightning-cli fundchannel $PUBLICKEY $SATOSHI

This will require that the funding transaction be confirmed before
you can send funds over Lightning.
To track this, use lightning-listpeers(7) and look at the 'state'
of the channel:

  $ lightning-cli listpeers $PUBLICKEY

The channel will initially start with a 'state' of
'CHANNELD_AWAITING_LOCKIN'.
You need to wait for the channel 'state' to become 'CHANNELD_NORMAL',
meaning the funding transaction has been confirmed deeply.

Once the channel 'state' is 'CHANNELD_NORMAL', you can start paying
merchants over Lightning.
Acquire a Lightning invoice from your favorite merchant, and use
lightning-pay(7) to pay it:

  $ lightning-cli pay $INVOICE

BUGS
----
You should report bugs on our github issues page, and maybe submit a
fix to gain our eternal gratitude!

AUTHOR
------
ZmnSCPxj <ZmnSCPxj@protonmail.com> wrote the initial version of this
man page, but many others did the hard work of actually implementing
a standards-compliant Lightning Network node implementation.

SEE ALSO
--------
lightning-listconfigs(7), lightning-config(5), lightning-cli(1),
lightning-newaddr(7), lightning-listfunds(7), lightning-connect(7),
lightning-fundchannel(7), lightning-listpeers(7), lightning-pay(7)

RESOURCES
---------
Main web site: https://github.com/ElementsProject/lightning

COPYING
-------
Note: the modules in the ccan/ directory have their own licenses, but
the rest of the code is covered by the BSD-style MIT license.