@utexo/rgb-lightning-node-nodejs

Node.js (napi-rs) bindings for rgb-lightning-node (RLN) — the Lightning + RGB daemon built on LDK and rgb-lib.

The Node counterpart to @utexo/rgb-lightning-node-bare — same underlying Rust C-FFI (librlncffi.a), same SdkNode + NativeExternalSigner JS API, picked automatically at module-load by @utexo/wdk-rgb-lightning based on the runtime (bare worklet → bare addon, Node → this package).

Why a separate package?

Node.js can dlopen shared libraries — the bare runtime can't. So while the Rust layer is shared, the JS-binding layer is forked:

• This package builds with napi-rs → one platform-specific .node per host (loaded dynamically at require).
• The bare sibling builds with cmake-bare → one self-contained .bare addon with the Rust statically linked in.

Both expose the same JS API surface, so the WDK layer (@utexo/wdk-rgb-lightning) writes a single code path that works in both runtimes.

Platform support

Prebuilt .node binaries ship via this repo's GitHub Releases; the postinstall script picks the right one based on host platform/arch.

Platform	Target
macOS arm64	darwin-arm64
macOS x64	darwin-x64
Linux x64 glibc	linux-x64-gnu
Linux x64 musl	linux-x64-musl
Linux arm64	linux-arm64-gnu

Installation

You don't normally install this package directly — it's a transitive peer dependency of @utexo/wdk-rgb-lightning in Node-side WDK demos. If you need RLN directly from Node, install it explicitly:

npm install @utexo/rgb-lightning-node-nodejs

A postinstall script downloads the matching .node prebuild from the GitHub Release for this package version. If postinstall was skipped (e.g. npm install --ignore-scripts), run it manually:

bash node_modules/@utexo/rgb-lightning-node-nodejs/scripts/download-libs.sh

Usage

The package exposes two classes (SdkNode and NativeExternalSigner) plus module-level helpers. The example below uses the external-signer lifecycle — the only mode the WDK ships with.

const rln = require('@utexo/rgb-lightning-node-nodejs')

// Create the node handle (does not open the network yet).
const node = rln.SdkNode.create({
  storage_dir_path: '/path/to/persistent/dir',
  daemon_listening_port: 0,
  ldk_peer_listening_port: 0,
  network: 'regtest',
  max_media_upload_size_mb: 5,
  enable_virtual_channels_v0: false
})

// Build the in-process VLS signer from a host-owned 32-byte seed.
const signer = rln.NativeExternalSigner.create(seedHex, 'regtest')

// First-launch init (writes key-source file to storage_dir_path).
// On subsequent launches RLN throws Rln(Conflict) — swallow it.
try { node.initWithNativeExternalSigner(signer) }
catch (e) { if (!String(e.message).includes('Conflict')) throw e }

// Bring the node online.
node.unlockWithNativeExternalSigner(signer, {
  bitcoind_rpc_username: 'user',
  bitcoind_rpc_password: 'pass',
  bitcoind_rpc_host: '127.0.0.1',
  bitcoind_rpc_port: 18443,
  indexer_url: 'tcp://localhost:50001',
  proxy_endpoint: 'rpc://localhost:3000/json-rpc',
  announce_addresses: [],
  announce_alias: 'my-node'
})

console.log(node.nodeInfo().pubkey)

// ...later
node.shutdown()

See index.js for the full method list (channels, invoices, payments, swaps, RGB asset ops, BTC ops, VSS, APay, signing, diagnostics).

Seed handling. RLN never sees the BIP-39 mnemonic. The host derives a 32-byte BIP-32 entropy and passes it as seedHex to NativeExternalSigner.create. The key-source file written by initWithNativeExternalSigner records only public identifying data (xpubs, node id, master fingerprint). Re-deriving from the same mnemonic on a later launch reproduces the same seedHex, which matches the on-disk key-source file — so the LDK node identity stays stable across restarts.

Architecture

JS                  Rust crate ("rln-node", crate-type=cdylib)        Static lib
─────────────       ──────────────────────────────────────────        ──────────────
SdkNode    ───►     #[napi] impl SdkNode { ... }            ───►      librlncffi.a
                       │                                                  │
NativeExternal ───►    #[napi] impl NativeExternalSigner    ─►           (same .a the
Signer                                                                    bare addon
                                                                          builds against)

Each #[napi] method serialises its request to a C string, calls the matching rln_* C-FFI function, and parses the CResultString back. Throws napi::Error on the Err branch.

Build from source (maintainers)

Requires the rln-c-ffi static lib built for the host (or whichever target you're cross-compiling for):

# In the rgb-lightning-node tree:
bash bindings/c-ffi/build-for-host.sh  # writes target/release/librlncffi.a

# Here:
npm install --ignore-scripts
npm run build       # release build  → index-<platform>.node
npm run build:debug # debug build (faster compile, slower runtime)

After building, tag and upload to GitHub Releases:

gh release create v0.1.0-beta.X index-*.node

License

Apache-2.0. See LICENSE.