core-lightning/doc/lightningd-config.5.md

lightningd-config -- Lightning daemon configuration file

SYNOPSIS

~/.lightning/config

DESCRIPTION

When lightningd(8) starts up, it reads a configuration file. By default that is config in the .lightning subdirectory of the home directory (if it exists), but that can be changed by the --lightning-dir or --conf options on the lightningd(8) command line.

Configuration file options are processed first, then command line options: later options override earlier ones except addr options which accumulate.

All these options are mirrored as commandline arguments to lightningd(8), so --foo becomes simply foo in the configuration file, and --foo=bar becomes foo=bar in the configuration file.

Blank lines and lines beginning with # are ignored.

DEBUGGING

--help will show you the defaults for many options; they vary with network settings so you can specify --network before --help to see the defaults for that network.

The lightning-listconfigs(7) command will output a valid configuration file using the current settings.

OPTIONS

General options

allow-deprecated-apis=BOOL Enable deprecated options, JSONRPC commands, fields, etc. It defaults to true, but you should set it to false when testing to ensure that an upgrade won’t break your configuration.

help Print help and exit. Not very useful inside a configuration file, but fun to put in other’s config files while their computer is unattended.

version Print version and exit. Also useless inside a configuration file, but putting this in someone’s config file may convince them to read this man page.

Bitcoin control options:

network=NETWORK Select the network parameters (bitcoin, testnet, or regtest).

testnet Alias for network=testnet.

signet Alias for network=signet.

mainnet Alias for network=bitcoin.

bitcoin-cli=PATH The name of bitcoin-cli executable to run.

bitcoin-datadir=DIR -datadir argument to supply to bitcoin-cli(1).

bitcoin-rpcuser=USER The RPC username for talking to bitcoind(1).

bitcoin-rpcpassword=PASSWORD The RPC password for talking to bitcoind(1).

bitcoin-rpcconnect=HOST The bitcoind(1) RPC host to connect to.

bitcoin-rpcport=PORT The bitcoind(1) RPC port to connect to.

bitcoin-retry-timeout=SECONDS Number of seconds to keep trying a bitcoin-cli(1) command. If the command keeps failing after this time, exit with a fatal error.

rescan=BLOCKS Number of blocks to rescan from the current head, or absolute blockheight if negative. This is only needed if something goes badly wrong.

Lightning daemon options

lightning-dir=DIR Sets the working directory. All files (except --conf and --lightning-dir on the command line) are relative to this.

pid-file=PATH Specify pid file to write to.

log-level=LEVEL What log level to print out: options are io, debug, info, unusual, broken.

log-prefix=PREFIX Prefix for log lines: this can be customized if you want to merge logs with multiple daemons.

log-file=PATH Log to this file instead of stdout. Sending lightningd(8) SIGHUP will cause it to reopen this file (useful for log rotation).

rpc-file=PATH Set JSON-RPC socket (or /dev/tty), such as for lightning-cli(1).

daemon Run in the background, suppress stdout and stderr.

conf=PATH Sets configuration file (default: lightning-dir/config ). If this is a relative path, it is relative to the starting directory, not lightning-dir (unlike other paths). PATH must exist and be readable (we allow missing files in the default case). Using this inside a configuration file is meaningless.

Lightning node customization options

alias=RRGGBB rgb=RRGGBB Your favorite color as a hex code.

Up to 32 UTF-8 characters to tag your node. Completely silly, since anyone can call their node anything they want. The default is an NSA-style codename derived from your public key, but "Peter Todd" and "VAULTERO" are good options, too.

fee-base=MILLISATOSHI Default: 1000. The base fee to charge for every payment which passes through. Note that millisatoshis are a very, very small unit! Changing this value will only affect new channels and not existing ones. If you want to change fees for existing channels, use the RPC call lightning-setchannelfee(7).

fee-per-satoshi=MILLIONTHS Default: 10 (0.001%). This is the proportional fee to charge for every payment which passes through. As percentages are too coarse, it’s in millionths, so 10000 is 1%, 1000 is 0.1%. Changing this value will only affect new channels and not existing ones. If you want to change fees for existing channels, use the RPC call lightning-setchannelfee(7).

min-capacity-sat=SATOSHI Default: 10000. This value defines the minimal effective channel capacity in satoshi to accept for channel opening requests. If a peer tries to open a channel smaller than this, the opening will be rejected.

ignore-fee-limits=BOOL Allow nodes which establish channels to us to set any fee they want. This may result in a channel which cannot be closed, should fees increase, but make channels far more reliable since we never close it due to unreasonable fees.

commit-time='MILLISECONDS How long to wait before sending commitment messages to the peer: in theory increasing this would reduce load, but your node would have to be extremely busy node for you to even notice.

Lightning channel and HTLC options

watchtime-blocks=BLOCKS How long we need to spot an outdated close attempt: on opening a channel we tell our peer that this is how long they’ll have to wait if they perform a unilateral close.

max-locktime-blocks=BLOCKS The longest our funds can be delayed (ie. the longest watchtime-blocks our peer can ask for, and also the longest HTLC timeout we will accept). If our peer asks for longer, we’ll refuse to create a channel, and if an HTLC asks for longer, we’ll refuse it.

funding-confirms=BLOCKS Confirmations required for the funding transaction when the other side opens a channel before the channel is usable.

commit-fee=PERCENT The percentage of estimatesmartfee 2 to use for the bitcoin transaction which funds a channel: can be greater than 100.

commit-fee-min=PERCENT commit-fee-max=PERCENT Limits on what onchain fee range we’ll allow when a node opens a channel with us, as a percentage of estimatesmartfee 2. If they’re outside this range, we abort their opening attempt. Note that commit-fee-max can (should!) be greater than 100.

max-concurrent-htlcs=INTEGER Number of HTLCs one channel can handle concurrently in each direction. Should be between 1 and 483 (default 30).

cltv-delta=BLOCKS The number of blocks between incoming payments and outgoing payments: this needs to be enough to make sure that if we have to, we can close the outgoing payment before the incoming, or redeem the incoming once the outgoing is redeemed.

cltv-final=BLOCKS The number of blocks to allow for payments we receive: if we have to, we might need to redeem this on-chain, so this is the number of blocks we have to do that.

Invoice control options:

autocleaninvoice-cycle=SECONDS Perform cleanup of expired invoices every SECONDS seconds, or disable if 0. Usually unpaid expired invoices are uninteresting, and just take up space in the database.

autocleaninvoice-expired-by=SECONDS Control how long invoices must have been expired before they are cleaned (if autocleaninvoice-cycle is non-zero).

Networking options

Note that for simple setups, the implicit autolisten option does the right thing: it will try to bind to port 9735 on IPv4 and IPv6, and will announce it to peers if it seems like a public address.

You can instead use addr to override this (eg. to change the port), or precisely control where to bind and what to announce with the bind-addr and announce-addr options. These will disable the autolisten logic, so you must specifiy exactly what you want!

addr=[IPADDRESS[:PORT]]|autotor:TORIPADDRESS[:TORPORT] Set an IP address (v4 or v6) or automatic Tor address to listen on and (maybe) announce as our node address.

An empty 'IPADDRESS' is a special value meaning bind to IPv4 and/or
IPv6 on all interfaces, '0.0.0.0' means bind to all IPv4
interfaces, '::' means 'bind to all IPv6 interfaces'.  If 'PORT' is
not specified, 9735 is used.  If we can determine a public IP
address from the resulting binding, and no other addresses of the
same type are already announced, the address is announced.

If the argument begins with 'autotor:' then it is followed by the
IPv4 or IPv6 address of the Tor control port (default port 9051),
and this will be used to configure a Tor hidden service for port
9735.  The Tor hidden service will be configured to point to the
first IPv4 or IPv6 address we bind to.

This option can be used multiple times to add more addresses, and
its use disables autolisten.  If necessary, and 'always-use-proxy'
is not specified, a DNS lookup may be done to resolve 'IPADDRESS'
or 'TORIPADDRESS'.

bind-addr=[IPADDRESS[:PORT]]|SOCKETPATH Set an IP address or UNIX domain socket to listen to, but do not announce. A UNIX domain socket is distinguished from an IP address by beginning with a /.

An empty 'IPADDRESS' is a special value meaning bind to IPv4 and/or
IPv6 on all interfaces, '0.0.0.0' means bind to all IPv4
interfaces, '::' means 'bind to all IPv6 interfaces'.  'PORT' is
not specified, 9735 is used.

This option can be used multiple times to add more addresses, and
its use disables autolisten.  If necessary, and 'always-use-proxy'
is not specified, a DNS lookup may be done to resolve 'IPADDRESS'.

announce-addr=IPADDRESS[:PORT]|TORADDRESS.onion[:PORT] Set an IP (v4 or v6) address or Tor address to announce; a Tor address is distinguished by ending in .onion. PORT defaults to 9735.

Empty or wildcard IPv4 and IPv6 addresses don't make sense here.
Also, unlike the 'addr' option, there is no checking that your
announced addresses are public (e.g. not localhost).

This option can be used multiple times to add more addresses, and
its use disables autolisten.  The spec says you can't announce
more that one address of the same type (eg. two IPv4 or two IPv6
addresses) so `lightningd` will refuse if you specify more than one.

If necessary, and 'always-use-proxy' is not specified, a DNS
lookup may be done to resolve 'IPADDRESS'.

offline Do not bind to any ports, and do not try to reconnect to any peers. This can be useful for maintenance and forensics, so is usually specified on the command line. Overrides all addr and bind-addr options.

autolisten=BOOL By default, we bind (and maybe announce) on IPv4 and IPv6 interfaces if no addr, bind-addr or announce-addr options are specified. Setting this to false disables that.

proxy=IPADDRESS[:PORT] Set a socks proxy to use to connect to Tor nodes (or for all connections if always-use-proxy is set).

always-use-proxy=BOOL Always use the proxy, even to connect to normal IP addresses (you can still connect to Unix domain sockets manually). This also disables all DNS lookups, to avoid leaking information.

disable-dns Disable the DNS bootstrapping mechanism to find a node by its node ID.

tor-service-password=PASSWORD Set a Tor control password, which may be needed for autotor: to authenticate to the Tor control port.

Lightning Plugins

lightningd(8) supports plugins, which offer additional configuration options and JSON-RPC methods, depending on the plugin. Some are supplied by default (usually located in libexec/c-lightning/plugins/). If a plugins directory exists under lightning-dir that is searched for plugins along with any immediate subdirectories). You can specify additional paths too:

plugin=PATH Specify a plugin to run as part of c-lightning. This can be specified multiple times to add multiple plugins.

plugin-dir=DIRECTORY Specify a directory to look for plugins; all executable files not containing punctuation (other than ., - or _) in 'DIRECTORY are loaded. DIRECTORY must exist; this can be specified multiple times to add multiple directories.

clear-plugins This option clears all plugin and plugin-dir options preceeding it, including the default built-in plugin directory. You can still add plugin-dir and plugin options following this and they will have the normal effect.

disable-plugin=PLUGIN If PLUGIN contains a /, plugins with the same path as PLUGIN are disabled. Otherwise, any plugin with that base name is disabled, whatever directory it is in.

BUGS

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

AUTHOR

Rusty Russell <rusty@rustcorp.com.au> wrote this man page, and much of the configuration language, but many others did the hard work of actually implementing these options.

SEE ALSO

lightning-listconfigs(7) lightning-setchannelfee(7) lightningd(8)

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.