FixerSharp

C# library to assist with currency conversion and exchange rates. Leverages the Fixer.io API.

Installation

Can be installed as a NuGet package. In the package manager console, enter the following:

Install-Package FixerSharp

Usage

Configure API Access

The fixer.io service now requires an API key for all operations. A free key allowing up to 1000 requests/month can be obtained by registering for a free account on the fixer.io website.

Your API key must be configured through the SetApiKey method before performing any conversion operations. This should only be required once during application startup (or equivalent):

using FixerSharp;

...

public class Startup
{
    ...

    public void Configure(IApplicationBuilder app)
    {
        ...

        // One-time call to SetApiKey
        Fixer.SetApiKey("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
    }
}

Convert

Perform a one-off conversion between two currencies:

using FixerSharp;

...

double oneHundredUsdInGbp = Fixer.Convert(Symbols.USD, Symbols.GBP, 100);
double oneThousandEurInUsd = await Fixer.ConvertAsync("EUR", "USD", 1000);

Exchange Rate

If you wish to perform additional conversions, the current exchange rate can be retrieved and used to convert:

using FixerSharp;

...

ExchangeRate rateUsdGbp = Fixer.Rate(Symbols.USD, Symbols.GBP);

double oneHundredUsdInGbp = rateUsdGbp.Convert(100);
double oneThousandUsdInGbp = rateUsdGbp.Convert(1000);
double tenThousandUsdInGbp = rateUsdGbp.Convert(10000);

ExchangeRate rateGbpEur = await Fixer.RateAsync(Symbols.GBP, Symbols.EUR);

double tenGbpInEur = rateGbpEur.Convert(10);
double oneHundredGbpInEur = rateGbpEur.Convert(100);

This method is recommended if you have more than one conversion to perform, as data is only retrieved from the fixer API once.

Previous Data

Both Convert and Rate have date support, allowing access to historical currency data for any day since 1999.

using FixerSharp;

...

// Calculates percentage difference of 100 GBP in USD between Nov 2015/16
double amount = Fixer.Convert(Symbols.GBP, Symbols.USD, 100, new DateTime(2016, 11, 01));
double amountPrevious = Fixer.Convert(Symbols.GBP, Symbols.USD, 100, new DateTime(2015, 11, 01));

double percentDifference = (amount - amountPrevious) / amountPrevious * 100; // -20.2952... :(

// Get the exchange rate for EUR => GBP on 1st January 2015
ExchangeRate historicalRate = Fixer.Rate(Symbols.EUR, Symbols.GBP);

double historicalConversion = historicalRate.Convert(500);

Acknowledgements

This makes use of the fixer project to provide up-to-date exchange rates.