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

lightningd-config -- Lightning daemon configuration file

SYNOPSIS

~/.lightning/config

DESCRIPTION

When lightningd(8) starts up it usually reads a general configuration file (default: $HOME/.lightning/config) then a network-specific configuration file (default: $HOME/.lightning/testnet/config). This can be changed: see --conf and --lightning-dir.

General configuration files are processed first, then network-specific ones, then command line options: later options override earlier ones except addr options and log-level with subsystems, which accumulate.

*include * followed by a filename includes another configuration file at that point, relative to the current configuration file.

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, signet, or regtest). This is not valid within the per-network configuration file.

mainnet Alias for network=bitcoin.

testnet Alias for network=testnet.

signet Alias for network=signet.

bitcoin-cli=PATH [plugin bcli] The name of bitcoin-cli executable to run.

bitcoin-datadir=DIR [plugin bcli] -datadir argument to supply to bitcoin-cli(1).

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

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

bitcoin-rpcconnect=HOST [plugin bcli] The bitcoind(1) RPC host to connect to.

bitcoin-rpcport=PORT [plugin bcli] The bitcoind(1) RPC port to connect to.

bitcoin-retry-timeout=SECONDS [plugin bcli] 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. This is only valid on the command-line, or in a configuration file specified by --conf.

subdaemon=SUBDAEMON:PATH Specifies an alternate subdaemon binary. Current subdaemons are channeld, closingd, connectd, gossipd, hsmd, onchaind, and openingd. If the supplied path is relative the subdaemon binary is found in the working directory. This option may be specified multiple times.

So, subdaemon=hsmd:remote_signer would use a hypothetical remote signing proxy instead of the standard lightning_hsmd binary.

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

log-level=LEVEL[:SUBSYSTEM] What log level to print out: options are io, debug, info, unusual, broken. If SUBSYSTEM is supplied, this sets the logging level for any subsystem containing that string. This option may be specified multiple times. Subsystems include:

• lightningd: The main lightning daemon

• database: The database subsystem

• wallet: The wallet subsystem

• gossipd: The gossip daemon

• plugin-manager: The plugin subsystem

• plugin-P: Each plugin, P = plugin path without directory

• hsmd: The secret-holding daemon

• connectd: The network connection daemon

• jsonrpc#FD: Each JSONRPC connection, FD = file descriptor number

  The following subsystems exist for each channel, where N is an incrementing internal integer id assigned for the lifetime of the channel:

• openingd-chan#N: Each opening / idling daemon

• channeld-chan#N: Each channel management daemon

• closingd-chan#N: Each closing negotiation daemon

• onchaind-chan#N: Each onchain close handling daemon

  So, log-level=debug:plugin would set debug level logging on all plugins and the plugin manager. log-level=io:chan#55 would set IO logging on channel number 55 (or 550, for that matter).

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).

log-timestamps=BOOL Set this to false to turn off timestamp prefixes (they will still appear in crash log files).

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

rpc-file-mode=MODE Set JSON-RPC socket file mode, as a 4-digit octal number. Default is 0600, meaning only the user that launched lightningd can command it. Set to 0660 to allow users with the same group to access the RPC as well.

daemon Run in the background, suppress stdout and stderr. Note that you need to specify log-file for this case.

conf=PATH Sets configuration file, and disable reading the normal general and network ones. 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 invalid.

wallet=DSN Identify the location of the wallet. This is a fully qualified data source name, including a scheme such as sqlite3 or postgres followed by the connection parameters.

The default wallet corresponds to the following DSN:

--wallet=sqlite3://$HOME/.lightning/bitcoin/lightningd.sqlite3

For the sqlite3 scheme, you can specify a single backup database file by separating it with a : character, like so:

--wallet=sqlite3://$HOME/.lightning/bitcoin/lightningd.sqlite3:/backup/lightningd.sqlite3

The following is an example of a postgresql wallet DSN:

--wallet=postgres://user:pass@localhost:5432/db_name

This will connect to a DB server running on localhost port 5432, authenticate with username user and password pass, and then use the database db_name. The database must exist, but the schema will be managed automatically by lightningd.

encrypted-hsm If set, you will be prompted to enter a password used to encrypt the hsm_secret. Note that once you encrypt the hsm_secret this option will be mandatory for lightningd to start. If there is no hsm_secret yet, lightningd will create a new encrypted secret. If you have an unencrypted hsm_secret you want to encrypt on-disk, or vice versa, see lightning-hsmtool(8).

Lightning node customization options

alias=NAME Up to 32 bytes of 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.

rgb=RRGGBB Your favorite color as a hex code.

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. This will reject any opening of a channel which can't pass an HTLC of least this value. Usually this prevents a peer opening a tiny channel, but it can also prevent a channel you open with a reasonable amount and the peer requesting such a large reserve that the capacity of the channel falls below this.

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.

force-feerates==VALUES Networks like regtest and testnet have unreliable fee estimates: we usually treat them as the minimum (253 sats/kw) if we can't get them. This allows override of one or more of our standard feerates (see lightning-feerates(7)). Up to 5 values, separated by '/' can be provided: if fewer are provided, then the final value is used for the remainder. The values are in per-kw (roughly 1/4 of bitcoind's per-kb values), and the order is "opening", "mutual_close", "unilateral_close", "delayed_to_us", "htlc_resolution", and "penalty".

You would usually put this option in the per-chain config file, to avoid setting it on Bitcoin mainnet! e.g. ~rusty/.lightning/regtest/config.

Lightning channel and HTLC options

large-channels Removes capacity limits for channel creation. Version 1.0 of the specification limited channel sizes to 16777215 satoshi. With this option (which your node will advertize to peers), your node will accept larger incoming channels and if the peer supports it, will open larger channels. Note: this option is spelled large-channels but it's pronounced wumbo.

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 [plugin bcli] The percentage of estimatesmartfee 2/CONSERVATIVE to use for the commitment transactions: default is 100.

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

max-dust-htlc-exposure-msat=MILLISATOSHI Option which limits the total amount of sats to be allowed as dust on a channel.

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 [plugin autoclean] 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 [plugin autoclean] Control how long invoices must have been expired before they are cleaned (if autocleaninvoice-cycle is non-zero).

Payment control options:

disable-mpp [plugin pay] Disable the multi-part payment sending support in the pay plugin. By default the MPP support is enabled, but it can be desirable to disable in situations in which each payment should result in a single HTLC being forwarded in the network.

Networking options

Note that for simple setups, the implicit autolisten option does the right thing: for the mainnet (bitcoin) network 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[:SERVICEPORT][/torport=TORPORT]|statictor:TORIPADDRESS[:SERVICEPORT][/torport=TORPORT][/torblob=[blob]]

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, the default port 9735 is used for mainnet (testnet: 19735, signet: 39735, regtest: 19846). If we can determine a public IP address from the resulting binding, 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 in case of mainnet (bitcoin) network whereas other networks (testnet, signet, regtest) will set the same default ports they use for non-Tor addresses (see above). The Tor hidden service will be configured to point to the first IPv4 or IPv6 address we bind to and is by default unique to your node's id.

If the argument begins with 'statictor:' 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 static Tor hidden service. You can add the text '/torblob=BLOB' followed by up to 64 Bytes of text to generate from this text a v3 onion service address text unique to the first 32 Byte of this text. You can also use an postfix '/torport=TORPORT' to select the external tor binding. The result is that over tor your node is accessible by a port defined by you and possibly different from your local node port assignment.

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.

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). The port defaults to 9050 if not specified.

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. Note that unless plugins themselves specify ordering requirements for being called on various hooks, plugins will be ordered by commandline, then config file.

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. The ordering of plugins within a directory is currently unspecified.

clear-plugins This option clears all plugin, important-plugin, and plugin-dir options preceeding it, including the default built-in plugin directory. You can still add plugin-dir, plugin, and important-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 will not be loaded at startup. Otherwise, no plugin with that base name will be loaded at startup, whatever directory it is in. This option is useful for disabling a single plugin inside a directory. You can still explicitly load plugins which have been disabled, using lightning-plugin(7) start.

important-plugin=PLUGIN Speciy a plugin to run as part of C-lightning. This can be specified multiple times to add multiple plugins. Plugins specified via this option are considered so important, that if the plugin stops for any reason (including via lightning-plugin(7) stop), C-lightning will also stop running. This way, you can monitor crashes of important plugins by simply monitoring if C-lightning terminates. Built-in plugins, which are installed with lightningd(8), are automatically considered important.

Experimental Options

Experimental options are subject to breakage between releases: they are made available for advanced users who want to test proposed features. When the build is configured without --enable-experimental-features, below options are available but disabled by default. A build with --enable-experimental-features enables some of below options by default and also adds support for even more features. Supported features can be listed with lightningd --list-features-only.

experimental-onion-messages

Specifying this enables sending, forwarding and receiving onion messages, which are in draft status in the BOLT specifications.

experimental-offers

Specifying this enables the offers and fetchinvoice plugins and corresponding functionality, which are in draft status as BOLT12. This usually requires experimental-onion-messages as well. See lightning-offer(7) and lightning-fetchinvoice(7).

fetchinvoice-noconnect

Specifying this prevents fetchinvoice and sendinvoice from trying to connect directly to the offering node as a last resort.

experimental-shutdown-wrong-funding

Specifying this allows the wrong_funding field in shutdown: if a remote node has opened a channel but claims it used the incorrect txid (and the channel hasn't been used yet at all) this allows them to negotiate a clean shutdown with the txid they offer.

experimental-dual-fund

Specifying this enables support for the dual funding protocol, allowing both parties to contribute funds to a channel. The decision about whether to add funds or not to a proposed channel is handled automatically by a plugin that implements the appropriate logic for your needs. The default behavior is to not contribute funds.

experimental-websocket-port=PORT

Specifying this enables support for accepting incoming WebSocket connections on that port, on any IPv4 and IPv6 addresses you listen to. The normal protocol is expected to be sent over WebSocket binary frames once the connection is upgraded.

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) lightning-hsmtool(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.