LDK Node

A ready-to-go Lightning node library built using LDK and BDK.

LDK Node is a non-custodial Lightning node in library form. Its central goal is to provide a small, simple, and straightforward interface that enables users to easily set up and run a Lightning node with an integrated on-chain wallet. While minimalism is at its core, LDK Node aims to be sufficiently modular and configurable to be useful for a variety of use cases.

Getting Started

The primary abstraction of the library is the Node, which can be retrieved by setting up and configuring a Builder to your liking and calling build(). Node can then be controlled via commands such as start, stop, connect_open_channel, send_payment, etc.:

use ldk_node::Builder;
use ldk_node::lightning_invoice::Invoice;
use ldk_node::bitcoin::secp256k1::PublicKey;
use std::str::FromStr;

fn main() {
	let node = Builder::new()
		.set_network("testnet")
		.set_esplora_server_url("https://blockstream.info/testnet/api".to_string())
		.build();

	node.start().unwrap();

	let _funding_address = node.new_funding_address();

	// .. fund address ..

	node.sync_wallets().unwrap();

	let node_id = PublicKey::from_str("NODE_ID").unwrap();
	let node_addr = "IP_ADDR:PORT".parse().unwrap();
	node.connect_open_channel(node_id, node_addr, 10000, None, false).unwrap();

	let invoice = Invoice::from_str("INVOICE_STR").unwrap();
	node.send_payment(&invoice).unwrap();

	node.stop().unwrap();
}

Modularity

LDK Node currently comes with a decidedly opionated set of design choices:

• On-chain data is handled by the integrated BDK wallet
• Chain data is accessed via Esplora (support for Electrum and bitcoind RPC will follow)
• Wallet and channel state is persisted to file system (support for SQLite will follow)
• Gossip data is sourced via Lightnings peer-to-peer network (support for Rapid Gossip Sync will follow)
• Entropy for the Lightning and on-chain wallets may be generated and persisted for or provided by the user (as raw bytes or BIP39 mnemonic)

Language Support

LDK Node is written in Rust and may therefore be natively included in any std Rust program. Beyond its Rust API it also offers language bindings for Swift, Kotlin, and Python based on UniFFI.