Error “request too large (413)” when trying to upload a PDF file to OneNote

Question

I'm trying to create new pages in OneNote using Microsoft Graph REST API (Objective-C). Those new pages should contain a PDF document as an attachment.

The POST operations succeed with PDF files that are under ~4MB. However, the operations for files that are over 4MB fail with the error message request too large (413) and the following response:

{
  "error": {
    "code": "BadRequest",
    "message": "Maximum request length exceeded.",
    "innerError": {
      "request-id": "269c663c-9289-47cc-a833-d471b7b867f6",
      "date": "2019-04-09T09:35:49"
    }
  }
}

The end point that is used is: https://graph.microsoft.com/v1.0/me/onenote/sections/XXX/pages

---

Microsoft states in the documentation for Graph and OneNote:

• The total POST size limit is ~70 MB, including images, files, and other data. The actual limit is affected by downstream encoding, so there's no fixed byte-count limit. Requests that exceed the limit may produce unreliable results.
• The limit for each data part is 25 MB, including the part headers. Data parts that exceed the limit are rejected by Microsoft Graph.

I could not find any limit of 4MB for POST requests in the Microsoft Graph documentation for OneNote. Is there any workaround for my current issue?

Answer 1

The short answer is that this documentation is incorrect. The longer answer requires a little background on Graph itself.

Graph is an API aggregator. It takes incoming requests, routes them to one or more underlying APIs, and then normalizes the responses so the end developer gets consistent results across endpoints.

In this case, the underlying API is the OneNote REST API. The limits mentioned in the docs are accurate in terms of the OneNote API but since this request is being handled by Graph, you are hitting the smaller 4 MB limit of Graph itself before that request ever gets routed to the underlying API.

More than likely the documentation error was unintentionally missed when the original docs were ported over to Graph. I've filed a documentation issue so it can be corrected.