Why Firebase Firestore count reads operations while I am just adding new documents only? - node.js

Question

I have created and an API endpoint with Firebase Functions usign node.js. This
API endpoint collect JSON data from client browser and I am saving that JSON data to Firebase Firestore databse using Firebase Functions.
While this works fine but when I see Firestore usage tab it's shows really high number of read operations even I have not created any read function till now.
My API is in Production and and current usage data is : Reads 9.7K, Writes 1K, Deletes 0.
I have already tried to check with Firebase Firestore Document and Pricing but never seems to find anything on this issue.
I am using Firestore add function to create document with an auto generated document id. ValidateSubscriberData() is a simple function to validate client req.body inputs which is JSON data.
app.post('/subscribe', (req, res) => {
let subscriber = {};
ValidateSubscriberData(req.body)
.then(data => {
subscriber = data;
//console.log(data);
subscriber.time = Date.now();
return subscriber;
})
.then(subscriber => {
//console.log(subscriber);
// noinspection JSCheckFunctionSignatures
return db.collection(subscriber.host).add(subscriber);
})
.then(document => {
console.log(document.id);
res.json({id: document.id, iid: subscriber.iid});
return 0;
})
.catch(error => {
console.log({SelfError: error});
res.json(error);
});
});
I don't know this is an issue with Firestore or I am doing something in a way that makes read operations internally but I want find a way so I can optimize my code.
English is not my first language and I am trying my best explain my issue.

Answer 1

I think Firestore is working perfectly fine and my code too. I assume Firebase is counting those reads which I made through Firebase Console.
To verify this I have clicked on Data tab on Firestore page and scroll down to make all document name/id visible. And after that I see 1K Reads added on my old stats. So its proven Firestore counting all reads even its from firebase console and it is obvious but my bad I have not thinking about this before.
I don't think this question has any relevance but may be people like me find it helpful before posting any silly question on this helpful platform.