XRPL Orderbook Reader

This repository takes XRPL Orderbook (book_offers) datasets and requested volume to exchange and calculates the effective exchange rates based on the requested and available liquidity.

Optionally certain checks can be specified (eg. book_offers on the other side of the book) to warn for limited (percentage) liquidity on the requested side, and possibly other side of the order book.

Typescript 3.8+ is required

How to use:

For now: See samples/Sample.ts

Call & get results

Please create one LiquidityCheck instance per pair (from/to).

  const Lc = new LiquidityCheck(Params)
  const Lq = await Lc.get()
  log(Lq.rate)

You can update Params and fetch new data, and get the results based on the new data with the refresh method. When called without input parameter (refresh()) existing Params will be used based on fresh order book information. If a new Params object is provided, the entire instance will be updated.

  // Lc instance already exists
  // const Lc = new LiquidityCheck(Params)
  
  Params.trade.amount += 1000

  Lc.refresh(Params)
  const newLq = await Lc.get()

Available options here.

Client

This lib. requires a connection to an XRPL node. There are two supported clients:

Preferred: xrpl-client - https://www.npmjs.com/package/xrpl-client

You can pass the entire class instance of xrpl-client to the Params object. You pass the class as client property.

new LiquidityCheck({
  <...>,
  client: new XrplClient()
})

Deprecated: rippled-ws-client - https://www.npmjs.com/package/rippled-ws-client

You can pass the send method of rippled-ws-client to the Params object as method property.

new LiquidityCheck({
  <...>,
  method: RippledWsClientInstance.send
})

Custom WebSocket/... implementation

You can pass a send method to the Params object. The send method passed to the Params should take an object with a command for rippled and return a Promise that will resolve to contain requested order book lines. You pass a function as method property.

new LiquidityCheck({
  <...>,
  method: (JsonRequestWithCommand) => {
    return new Promise(resolve) {
      // Custom implementation to fetch the book results
    }
  }
})

Sample in JS (not TS) environment(s):

Please see /samples/PlainSample.js

How to...

Test:

npm run test

Run development code:

npm run dev (Compiles and runs /samples/Sample.ts)