title: How do cursors work on Firestore's REST API?
body: <p>I'm trying to build a structured query using the rest API for Firestore.
  There is one thing I don't quite understand. According to the docs I need to provide a cursor for the <code>startAt</code> or <code>endAt</code> arguments(when used), and a cursor consists of two props, the first one is an array of <code>Values</code>.</p>
  
  <pre><code>{
    "values": [
      {
        object(Value)
      }
    ],
    "before": boolean
  }
  </code></pre>
  
  <p>The docs: <a href="https://firebase.google.com/docs/firestore/reference/rest/v1beta1/StructuredQuery#cursor" rel="nofollow noreferrer">https://firebase.google.com/docs/firestore/reference/rest/v1beta1/StructuredQuery#cursor</a>.</p>
  
  <p>My question is, how exactly am I supposed to use this?
  It is my understanding that a cursor represents a position on a list of documents(in this case, a list made by a query), but how do the values prop comes into play?</p>
  
  <p>Thanks!</p>