Run a WASM Node

TL;DR

Install fiber-wasm, call fiber(config) with a TOML config string, and you have a full Fiber node running in the browser or Node.js. No backend server needed.

fiber-js is a WebAssembly (WASM) build of the Fiber Network Node. It runs directly in the browser or Node.js and provides the same core functionality as the native Rust node (fnn) — embedded in your JavaScript app.

	Native Node	WASM Node
Runtime	Native binary	Browser or Node.js
Deployment	Server or local machine	Embedded in web app
Public IP required	Yes	No — relay nodes supported
Storage	File system (SQLite/RocksDB)	IndexedDB (via WASM worker)
Use case	Production node operators	Browser wallets, web games, client-side dApps

Installation

npm install fiber-wasm
# or
pnpm add fiber-wasm

Quick Start

import init, { fiber, node_info, connect_peer, open_channel, send_payment, new_invoice } from 'fiber-wasm';

// 1. Initialize the WASM module
await init();

// 2. Start the Fiber node with a TOML config
const config = `
[fiber]
listening_addr = "/ip4/0.0.0.0/tcp/0"
chain = "testnet"
announce_listening_addr = false
bootnode_addrs = ["/ip4/54.179.226.154/tcp/8228/p2p/Qmes1EBD4yNo9Ywkfe6eRw9tG1nVNGLDmMud1xJMsoYFKy"]

[rpc]
listening_addr = "127.0.0.1:8227"

[ckb]
rpc_url = "https://testnet.ckbapp.dev/"
`;

await fiber(config, "info");

// 3. Get node info
const info = await node_info();
console.log("Node started:", info);

Expected Output: The node initializes, connects to bootnodes, and starts syncing. node_info() returns your node's pubkey, version, and chain info.

Common Workflows

Open a Channel and Send a Payment

// Connect to a public testnet node
await connect_peer({
  pubkey: "02b6d4e3ab86a2ca2fad6fae0ecb2e1e559e0b911939872a90abdda6d20302be71"
});

// Open a channel
await open_channel({
  pubkey: "02b6d4e3ab86a2ca2fad6fae0ecb2e1e559e0b911939872a90abdda6d20302be71",
  funding_amount: 49900000000, // 499 CKB in shannons
  public: true
});

// Create an invoice on the receiving end
const invoice = await new_invoice({
  amount: 100000000, // 1 CKB
  currency: "fibt",
  description: "Test payment"
});

// Send the payment
await send_payment({ invoice: invoice.encoded });

Keysend (No Invoice)

await send_payment({
  target_pubkey: "<recipient_pubkey>",
  amount: 100000000,
  keysend: true
});

Error Handling

try {
  const result = await send_payment({ invoice: "fibt1..." });
} catch (err) {
  console.error("Payment failed:", err);
}

Common errors:

"Fiber not started!" — Call fiber() first
"Fiber panicked, please refresh page" — Critical error; refresh the page
Configuration errors — Check your TOML config string

API Reference

fiber-js exposes 7 modules with 24 functions. All async functions return Promise<Result<JsValue, JsValue>>.

Module	Key Functions
Init	`fiber(config, log_level)`
Channel	`open_channel`, `list_channels`, `shutdown_channel`, `update_channel`
Payment	`send_payment`, `get_payment`, `build_router`
Invoice	`new_invoice`, `parse_invoice`, `get_invoice`, `cancel_invoice`
Peer	`connect_peer`, `disconnect_peer`, `list_peers`
Graph	`graph_nodes`, `graph_channels`
Node	`node_info`

For the full API reference see SDKs & APIs → fiber-js.

Next Steps

Basic Transfer — send your first payment using fiber-js
Build a Game with Fiber — end-to-end example using fiber-js