Error on Update request BadRequest: Version bytes exceeds treshhold


I am calling an Update request using FaunaDB JS Driver from an application that I am running locally and I am getting a Bad Request error.

The request is returning the following error:

BadRequest {name: "BadRequest", message: "bad request", description: "Version bytes (8399875) exceeds threshold (8388608)", requestResult: RequestResult}

I am basically updating a document in the books collection by adding one chapter of a long book per request (so I avoid the limit of 1MB per request).

It works fine for the first 28 chapters of my loop, but it always gives this error in the 29th chapter. It seems to be a regular chapter in terms of length of text, and it is well below 1MB, so I am not sure what is causing it.

The object that I am passing as data in the Update request is like this:

data: {
    books: {
        installments: {
            "29": {
                number: 29,
               title: `Installment #$29`,
               text: <a veeery long string here, of about 30kb>,
               bindedNote: ""


Any idea what is the problem?

@Soneca you have hit the maximum document size limit of 8 MB.

Oh, didn’t know about that. Ok, thanks.