@exodus/price-api

@exodus/price-api

Util to fetch, validate and cache prices from server

Table of Contents

• Installation
• Quick Start

Installation

yarn add @exodus/price-api

Quick start

Module contains following useful utils:

fetchHistoricalPrices

Based on provided arguments prepares params for request to exodus pricing server. Depending on runtime cache and client long-term cache decides how much data needs to be fetched. Validates data and prepares result to defined data structure.

Arguments

prices cache example: [1502496000000, {close: 44}], [1502582400000, {close: 12}] ]

Name	Type	Description	Optional	Returns
api	Function	Function to make request to pricing server		Promise
assetTickers	Array	Array of asset tickers to fetch
fiatTicker	String	fiat currency supported by Exodus, as well as BTC
granularity	String	Granularity of the historical data, values must be day or hour
getCacheFromStorage	Function	accepts tickerSymbol and returns array historical prices		prices cache
hourlyLimit	Number	limits historical hourly prices to fetch. default=168	true
timestamp	Number	milliseconds since Unix Epoch to fetch price exact on this date	true
getCurrentTime	Function	returns milliseconds since Unix Epoch	true	milliseconds
ignoreInvalidSymbols	Bool	ignore error when fetch prices for unsupported assets. Empty Map will be returned for this asset	true
ignoreCache	Bool	refetch the entire price history, ignoring existent cached values	true
runtimeCache	Map	storage for runtime cache	true
getRuntimeCacheKey	Function	get key to access runtime cache	true

Returns

Object with Maps with prices Maps by asset ticker. prices Map keyed by timestamp in milliseconds. historicalPricesMap includes prices from cache fetchedPricesMap includes only assets fetched from server. If asset had cache but new prices fetched from server this Map includes combined data

{
  historicalPricesMap: new Map([
 ['ZRX', new Map([ [1502496000000, {close: 44}], [1502582400000, {close: 12}] ])],
 ['BTC', new Map([ [1502496000000, {close: 10000}], [1502582400000, {close: 50000}] ])],
]),
  fetchedPricesMap: new Map([
 ['ZRX', new Map([ [1502496000000, {close: 44}], [1502582400000, {close: 12}] ])],
 ['BTC', new Map([ [1502496000000, {close: 10000}], [1502582400000, {close: 50000}] ])],
])
}

fetchPricesInterval

Setup interval to fetch prices. Daily prices updated on UTC day start, hourly every UTC and local hour start.

Arguments

Name	Type	Description	Optional
func	Function	Function to make fetch prices
granularity	Array	Granularity of the historical data, values must be day or hour
getJitter	Function	Function that returns jitter (ms) to create delay in [0, jitter] range	true
delay	Number	delay in milliseconds	true
getCurrentTime	Function	returns milliseconds since Unix Epoch	true