---
title: "introduction to currencyapi"
author: Dominik Kukacka
date: "`r Sys.Date()`"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{introduction}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
```

# Introduction

`currencyapi-r` is the official package for accessing currency conversion data from [currencyapi.com](https://currencyapi.com). The API requires a registered API key. The free plan provides 150 free monthly requests. You can register an API key [here](https://app.currencyapi.com/register). [Premium plans](https://currencyapi.com/pricing/) provide access to more requests, more endpoint and access to higher data update rates.
The full API documentation can be found [here](https://currencyapi.com/docs/)

## Setting up authentication

After registering your API key, set your API key locally by calling the helper function `currencyapi_api_key()` or by manually calling `Sys.setenv(CURRENCYAPI_API_KEY = <key>)`.

## Making your first API request

Call `get_latest_exchange_rates()` to retrieve the most recent exchange rates. By default, `USD` is set as `base_currency`. For API keys related to the free plan, data is updated daily, for premium plans up to minutely.

## Supported Currencies

Call `get_supported_currencies` to retrieve a list of all currencies that are supported by the API. 

## Available Functions

* `get_api_status()` - can be used to check whether the API is available. Requests do not count towards your monthly request volume. Information about your API key are provided. Available in `free & paid` plans
* `get_latest_exchange_rates()` - provides you with the latest exchange rates. Available in `free & paid` plans.
* `get_supported_currencies()` - provides a list of all currencies that are supported by the API. Available in `free & paid` plans.
* `get_historical_exchange_rates()` - provides exchange rate for a historical exchange rates for a given date. Available in `free & paid` plans.
* `convert_exchange_rates()` - Converts a given amount to another currency. Available in `paid` plans.
* `get_date_range_historical_exchange_rates()` - provides exchange rates for a given time frame.  Available in `paid` plans.

Please read our [API documentation](https://currencyapi.com/docs/) for all information.