Overview

So Bitcoin is running. Why bolt a second network on top of it?

Because Bitcoin's base layer is deliberately slow and deliberately expensive. Every transaction lands in a block that thousands of nodes worldwide will validate and store forever, and that's exactly what you want for settling serious money, not for buying a coffee. The Lightning Network is the second layer that fixes the coffee problem: payments settle in milliseconds, cost fractions of a cent, and only touch the base chain when a channel opens or closes.

This section turns your Bitcoin node into a Lightning node.

What you'll do

By the end of this section you'll have:

• LND running as a systemd service, connected to bitcoind over RPC + ZMQ, and routing its own peer traffic through Tor.
• A 24-word seed written down on paper and locked away, the only rope back to your on-chain funds if the Pi dies.
• Ride The Lightning (RTL) on https://rtl.raspibolt.local, reachable from your LAN so you can manage channels in a browser.
• Zeus on your phone, connected to the Pi over a private Tor onion, full node control from wherever you are.
• An automated channel backup that rsyncs your channel.backup file to an offsite host every time it changes.

Budget roughly two to three hours of hands-on time, most of it waiting for npm install and your first channel to confirm.

Assumptions

• You finished the Bitcoin section and bitcoind is fully synced, Lightning won't initial-sync its graph against a blockchain that's still catching up.
• bitcoind exposes the RPC port on 127.0.0.1:8332 and the ZMQ streams on ports 28332 and 28333, exactly as configured in Bitcoin client.
• Tor is installed and its SOCKS proxy is live on 127.0.0.1:9050 (see Privacy).
• Caddy is running as the reverse proxy for your LAN-only services, installed earlier in the Bitcoin section.

If you want to see where LND plugs into everything else before diving in, Architecture has the full picture.

Pages in this section

1. Lightning client, download, verify, and run LND 0.20.1-beta; create the wallet and seed; set up auto-unlock.
2. Web app, install Node.js and RTL 0.15.6; point it at LND; expose it through Caddy.
3. Mobile app, set up a Tor hidden service for LND's REST API and pair the Zeus phone app with it.
4. Channel backup, watch the channel.backup file and ship a copy offsite on every change; walk through the restore flow.

When Lightning is up, keep an eye on it for a few days before committing serious sats. Channels that open smoothly don't always close smoothly, and you'll want to see a few state updates flow through the backup pipeline before trusting it.