🏅Boltz Pro

Boltz Pro is a service designed to dynamically adjust swap fees based on Boltz's liquidity needs, helping to maintain wallet and Lightning channel balances.

Basics

Boltz Client is the recommended way to programmatically interact with Boltz Pro to check for fee discounts, identify earn opportunities, and trigger swaps.

To configure Boltz Client to use the Boltz Pro API, simply start the daemon with the --pro startup flag or set the pro configuration option. Since Boltz Pro discounts and earn opportunities are primarily available for Chain -> Lightning swaps, this guide will focus on that setup.

Boltz Client exposes a powerful gRPC API, which you can integrate into your own applications. For scripted usage of boltzcli, use the --json flag, which is available on most commands.

The current fee rates can be retrieved using the GetPairs endpoint or with the boltzcli getpairs command.

Here is an example for querying the current service fee for a Bitcoin -> Lightning swap using boltzcli and jq for processing the JSON output:

boltzcli getpairs --json | jq '.submarine[] | select(.pair.from == "BTC") | .fees.percentage'

Paying Lightning Invoices

Paying invoices of your own node

• Connect Boltz Client to your CLN or LND node

• Set the amount field to automatically generate a new invoice

• Example: boltzcli createswap 100000 btc (100k sats)

Paying invoices of an external service

• Start Boltz Client in standalone mode

• Provide an existing invoice via --invoice or the invoice field

• Example: boltzcli createswap --invoice lnbc1... btc

Funding Swaps

You can fund swaps in two ways:

1. Using Boltz Client's internal wallets

2. Using an external wallet

This choice is controlled by:

• API: send_from_internal parameter in CreateSwapRequest
• CLI: --from-wallet <wallet-name> (internal) or --external-pay (external). If neither is specified, the first internal wallet with the correct currency will be used for funding.