Calls the 'CoinMarketCap' API with the key from use_api_key().
Value
A data frame with one row per coin, sorted by market cap, with a
name_symbol label and the USD price, volume, price change, market cap
and dominance columns shown in the app.
Examples
if (FALSE) { # \dontrun{
listings <- crypto:::fetch_listings()
head(listings)
} # }