title: Cannot find namespace 'FirebaseFirestore' - Node.js, Express, Typescript
body: <p>I'm using the Firebase Admin SDK in my Express + Typescript server. I'm trying to use Firestore's method <a href="https://googleapis.dev/nodejs/firestore/latest/Query.html#withConverter" rel="nofollow noreferrer">withConverter()</a> However, I get the error &quot;Cannot find namespace 'FirebaseFirestore'.ts(2503)&quot;. How can I deal with this?</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>admin.initializeApp({
      credential: admin.credential.cert(serviceAccount)
  });
  
  const firestore = admin.firestore();
  
  interface BlogpostColletion {
      text: String,
      title: String,
  }
  
  interface UsersCollection {
      blogposts: BlogpostColletion
  }
  
  const converter = {
      toFirestore: (data: UsersCollection) =&gt; data,
      // PROBLEM HERE "Cannot find namespace 'FirebaseFirestore'.ts(2503)" 
      fromFirestore: (snap: FirebaseFirestore.QueryDocumentSnapshot) =&gt;
          snap.data() as UsersCollection
  }</code></pre>
  </div>
  </div>
  </p>