exchange

Go library for current & historical exchange rates, forex & crypto currency conversion, fluctuation, and timeseries using the new Free foreign exchange rates API by arzzen (github)

Features:

• Currency conversion, historical & current exchange rates, timeseries and fluctuations
• No authentication/token needed!
• Select any base currency
• 171 forex currency and 6000+ cryptocurrency!
• Caching (optional, default) using go-cache
• Easy to use:

Usage:

go get -u github.com/asvvvad/exchange

package main

import (
	"fmt"

	"github.com/asvvvad/exchange"
)

func main() {
	// Create a new Exchange instance and set USD as the base currency for the exchange rates and conversion
	ex := exchange.New("USD")
	// convert 10 USD to EUR
	fmt.Println(ex.ConvertTo("EUR", 10))
	// You can convert between 171 fiat and +6000 cryptocurrency aswelL!
	// convert 10 USD to BTC
	fmt.Println(ex.ConvertTo("BTC", 10))
	// convert 10 USD to EUR at 2012-12-12 (date must be in the format YYYY-MM-DD)
	fmt.Println(ex.ConvertAt("2012-12-12", "EUR", 10))

	// Get the available forex/fiat codes ([]string)
	forexCodes, _ := ex.ForexCodes()
	
	// Get the available crypto codes ([]string)
	// Warning: +6000
	cryptoCodes, _ := ex.CryptoCodes()

	// Get the forex codes data, includes code and description.
	forexData, _ := ex.ForexData()

	// Get the crypto codes data, includes code and description.
	// Warning: +6000
	cryptoData, _ := ex.CryptoData()

	// loop through the forex cpdes
	for _, code := range forexCodes {
		// print the forex codes data in the format: USD: US Dollar
		fmt.Println(code+":", forexData[code]["description"])
	}

	// Change the base currency to euro
	ex.SetBase("EUR")
	// Get the latest exchange rates with all currencies (Base is EUR)
	fmt.Println(ex.LatestRatesAll())

	// Get the latest rates again, this time it will be loaded from in-memory cache
	// Cache last till midnight GMT because it's the time exchangerate.host update the rates
	fmt.Println(ex.LatestRatesAll())
	// disable caching
	ex.SetCache(false)

	// Get the latest rates with multiple currencies, not all (USD and JPY only)
	fmt.Println(ex.LatestRatesMultiple([]string{"USD", "JPY"}))

	// Get the exchange rates at 2012-12-12 but only with USD
	fmt.Println(ex.HistoricalRatesSingle("2012-12-12", "USD"))

	// Get historical rates between 2012 12 10 and 2012 12 12 for JPY and GBP
	fmt.Println(ex.TimeseriesMultiple("2012-12-10", "2012-12-12", []string{"USD", "JPY"}))

	// Get the fluctuation between 2012 12 10 and 2012 12 12 with USD
	fluctuation, _ := ex.FluctuationSingle("2012-12-10", "2012-12-12", "USD")
	// Print the change
	fmt.Println(fluctuation["change"])
}

Results returned by each method:

• ConvertTo, ConvertAt, HistoricalRatesSingle, LatestRatesSingle

• • big.Float, error

• LatestRatesAll, LatestRatesMultiple, HistoricalRatesAll, HistoricalRatesMultiple:

• • map[symbol(string)]rate(big.Float)

• ForexCodes

• • []string{codes}, error

• ForexData

• • map[symbol]map[ code description ]string, error

• CryptoCodes

• • []string{codes}, error

• CryptoData

• • map[symbol]map[ symbol name ]string, error

• FluctuationAll, FluctuationMultiple,

• • map[symbol]map[ start_rate end_rate change change_pct ]*big.Float, error

• FluctuationSingle

• • map[ start_rate end_rate change change_pct ]*big.Float, error

• TimeseriesAll, TimeseriesMultiple

• • map[date]map[symbols]*big.Float, error

• TimeseriesSingle

• • map[date]map[symbol]*big.Float, error

Notes:

• You can use All, Multiple, Single with all of LatestRates, HistoricalRates, Timeseries and Fluctuation.
• Oldest date for historical rates and conversion is 1999-01-04
• Maximum allowed timeframe for Timeseries is 365 days

Input validation with the appropriate errors for all methods is provided to help debug

Any help and contribution is welcome!

This is my first Go library and I had trouble with JSON parsing (and I still do, didn't use bitly/simplejson to reduce dependencies) Theres a lot of room for improvement