RFQ

Request For Quote (RFQ) is a mechanism that simplifies sending Taproot Assets over Lightning Network channels.

When sending Taproot Assets over the Lightning Network, an Edge Node is needed. This Edge Node receives the Taproot Asset in the channel with the direct user and swaps it for bitcoin. As the swap rate between Taproot Assets and bitcoin likely fluctuates, the user may make a Request for Quote to the Edge Node before generating a Lightning Network invoice or initiating a payment.

This request is made using BOLT 01 messages over an existing encrypted and authenticated BOLT 08 connection. The connection already exists because it is used for establishing and coordinating the Taproot Asset Channel in a way very similiar to normal Lightning channels. For more information about connection and messaging, see the Last Mile Routing section of Taproot Asset Channels bLIP.

Learn more: Edge Nodes

The Request for Quote contains a rate and an expiration time, which allows the sender to decide whether they want to complete the payment and craft a route to the intended recipient.

Similarly when receiving Taproot Assets over the Lightning Network, RFQ is used by the recipient to generate a satoshi-denominated Lightning invoice.

Testing configuration

For testing purposes, tapd includes a mock oracle. This oracle allows the tester to set up a static exchange rate between Taproot Assets and bitcoin. When added to lit.conf, all Taproot Assets configuration options have to be pre-fixed with taproot-assets.

taproot-assets.experimental.rfq.priceoracleaddress=use_mock_price_oracle_service_promise_to_not_use_on_mainnet

You may set a fixed swap rate directly in the tapd.conf file as well in Taproot Assets units per bitcoin to avoid building your own custom price oracle. To trade one unit per satoshi for example, set the value to 1:

taproot-assets.experimental.rfq.mockoraclesatsperasset=1

Alternatively, you can also set a price of asset per Bitcoin. Remember that if your asset has decimal places, enter the full precision. So if your asset carries two decimal places, add two zeroes. In the below example, we define the price of our asset as one asset per satoshi, without decimal places:

taproot-assets.experimental.rfq.mockoracleassetsperbtc=100000000

Both peers of a Taproot Assets channel may set up an RFQ oracle. Alternatively, one of the nodes may chose to operate without an oracle, simply accepting all quotes from the Edge Node:

taproot-assets.experimental.rfq.skipacceptquotepricecheck=true

Oracle Demo

A basic price oracle has been implemented as part of the Taproot Assets code base. It makes use of the QueryRateTick RPC method to return a rate tick for a given transaction type, subject asset and payment asset.

Fork it: Taproot Assets Oracle Demo

You may also make a copy of the above spreadsheet here.