title: "You must provide a hash." error when using API to download data (in R)
body: <p>I would like to extract the data from MARVEL DEVELOPER by API code and analyze it (using R).</p>
  
  <p>I got the following url from MARVEL website: <a href="http://gateway.marvel.com:80/v1/public/characters?apikey=f389fcb49ad574e10ca570867f4bfa43" rel="noreferrer">http://gateway.marvel.com:80/v1/public/characters?apikey=f389fcb49ad574e10ca570867f4bfa43</a> </p>
  
  <p>I used httr package to collect the data: </p>
  
  <pre><code>install.packages("httr")
  library(httr)
  &gt; url &lt;- GET("http://gateway.marvel.com:80/v1/public/characters?orderBy=name&amp;limit=100&amp;apikey=f389fcb49ad574e10ca570867f4bfa43")
  &gt; content(url)
  $code
  [1] "MissingParameter"
  
  $message
  [1] "You must provide a hash."
  </code></pre>
  
  <p>I want to extract all this data to R. What should I do/read?</p>
  
  <p>Thanks.</p>