Add comments to SharePoint list items using the REST API

One of the newest features to come to SharePoint Online is the ability to add comments within the activity panel on SharePoint list items. In a previous post, I talked about how we can retrieve these new comments using the SharePoint REST API.

List comments are a great new way for users to collaborate together on list items as users can have threaded conversations with one another.

In the past we would have used a multi-line text column with “append changes” to create threaded conversations on list items. The problem with this is this method creates new versions and those comments are difficult to retrieve programmatically. Please see my post on retrieving values in multi-line text fields more efficiently.

Add a comment using the REST API

Recently, I’ve been seeing more posts on support forums and in social asking how these comments can be accessed and created programmatically. Well, like most things in the modern interface, they are implemented using client-side code, which must mean there is a REST API backing the functionality.

You will need to execute a POST request to the following endpoint


Parameters – The parameter you will pass through the body is called “text”. Construct your JSON object as {“text”:”your sample comment”}

fetch("'Test')/items(<ItemId>)/Comments()", {
"headers": {
"accept": "application/json;odata=verbose",
"content-type": "application/json;charset=UTF-8",
"x-requestdigest": "<yourRequestDigest""
"body": "{\"text\":\"Add a new comment\"}",
"method": "POST",
"mode": "cors",
"credentials": "include"

Using the above POST call, you can submit a new comment to the list item as the current user (there is no way to add list item comments on-behalf of another user). When you execute the request and update your x-requestdigest, and the appropriate values for the URI, your comment will be successfully added to the list item (see below).

I hope you find this post helpful and if you have any questions, please feel free to reach out!

SharePoint Online – Retrieve values of a multi-line text field with append changes in a single REST call

One of the most common questions I see in SharePoint support forums is how to retrieve the history of a multi-line text field with “append changes” in SharePoint. In most cases, the answer is to retrieve each previous version of a SharePoint item and iterate through them to construct all values in the multi-line text field.

The reasoning behind this is fairly obvious — each instance of a change in the multi-line text field is stored in a separate version of the SharePoint item.

Take for example the following Test list. This list contains a title field and a multi-line text field with “append changes”

If you open up the information panel for this item, you will see the multiline text field with the previous values. Notice how I have updated this item twice and added a value to the Multi field multiple times.

In order to see how SharePoint stores this data, check out the version history. The version history shows the two times I have edited the item, with the latest version being the most recent value in the multi-line text field.

Now you can see why you need to loop through versions. If you did a standard REST call using something like _api/web/lists/getbytitle(‘Test’)/items(1), the Multi column would only have the value of “My second comment in the multiline text field”.

Well, fear no more! There is in fact a way to retrieve the values in your list item without having to iterate over each previous version of the item.

Introducing RenderExtendedListFormData()

An unknown and undocumented REST endpoint exists in SharePoint Online called RenderExtendedListFormData() is the solution we need. You may be saying, “oh, we shouldn’t use undocumented REST endpoints”. Valid point, however, you should be aware that this endpoint is exactly what is used when rendering the information pane in Modern SharePoint via first-party.

Below you will see how to make this request into SharePoint. The RenderExtendedListFormData method is a POST call and takes 5 parameters:

itemId – The ID of your list item

formId – The form name (this is how MSFT determines what fields are returned in the request based on the form)

mode – I haven’t figured out what this means yet

options – I haven’t figured out what this means yet

cutoffVersion – Which is the latest version you want to pull. e.g, if you pass in 0, it will retrieve every version up until the first. If you pass in “2” it will put every version up until 2.0.

fetch(",formId='editform',mode='2',options=47,cutoffVersion=0)?@v1=%27%2Fsites%2Fcontosoportal%2FLists%2FTest%27", {
   "headers": {
     "accept": "application/json;odata=verbose",
     "accept-language": "en-US,en;q=0.9",
     "content-type": "application/json;odata=verbose",
     "sec-fetch-dest": "empty",
     "sec-fetch-mode": "cors",
     "sec-fetch-site": "same-origin",
     "x-requestdigest": "<yourRequestDigest>",
   "referrer": "",
   "referrerPolicy": "strict-origin-when-cross-origin",
   "body": "",
   "method": "POST",
   "mode": "cors",
   "credentials": "include"

The Response

The response from this call includes a lot of data as it’s used for the rendering of the edit form, but if you look closely you’ll notice the values for the multiline text field are stored in d.RenderExtendedListFormData.<ColumName>

The Multi (your column name) object contains all of the values in the multi-line text field based on the parameters of my REST call above. The response includes the text value, who wrote the value (email, title, id) as well as when the item was created.

HOW AWESOME IS THAT?! I retrieved all appended changes of my multi-line text field, using a single REST call.

Caveats + FYI

As mentioned previously, this is an undocumented REST endpoint. Even though this is used first-party by Microsoft, you should be aware this endpoint is subject to change and your solutions will have a dependency on that. Use at your own risk!

If you know what the other parameters (mode / option) mean in the REST call, I’d love to find out! Please message me if you know!

Retrieve Modern SharePoint list item comments using REST

Recently someone had posted on a SharePoint support forum asking whether or not it was possible to retrieve the new modern list item comments programmatically. In case you haven’t seen this yet, Microsoft has introduced the ability for users to add comments to the activity feed on list items in SharePoint.

To add a comment, navigate to your list item, open up the information pane and scroll to bottom. You will see the activity feed where you can add, remove and view comments from yourself and others on a list item.

While the endpoint is not yet documented, it is indeed possible to interact with these comments. However, be aware, the comments are not apart of the list item object in REST, you must call a different endpoint to retrieve the values.

Get list item comments using REST

To retrieve all of the comments on a list item using REST, you can make a GET call the following API endpoint.


Here is the response

    "d": {
        "results": [{
            "__metadata": {
                "id": "'43f52951-64fa-4362-b03e-4fefde369da9')/GetItemById(1)/Comments(1)",
                "uri": "'43f52951-64fa-4362-b03e-4fefde369da9')/GetItemById(1)/Comments(1)",
                "type": "Microsoft.SharePoint.Comments.comment"
            "likedBy": {
                "__deferred": {
                    "uri": "'43f52951-64fa-4362-b03e-4fefde369da9')/GetItemById(1)/Comments(1)/likedBy"
            "replies": {
                "results": []
            "author": {
                "__metadata": {
                    "type": "SP.Shring.Principal"
                "email": "",
                "expiration": null,
                "id": 6,
                "isActive": true,
                "isExternal": false,
                "jobTitle": null,
                "loginName": "i:0#.f|membership|",
                "name": "Beau Cameron",
                "principalType": 1,
                "userId": null,
                "userPrincipalName": null
            "createdDate": "2020-12-15T21:32:05.52Z",
            "id": "1",
            "isLikedByUser": false,
            "isReply": false,
            "itemId": 1,
            "likeCount": 0,
            "listId": "43f52951-64fa-4362-b03e-4fefde369da9",
            "mentions": {
                "__metadata": {
                    "type": "Collection(Microsoft.SharePoint.Comments.Client.Identity)"
                "results": []
            "parentId": "0",
            "replyCount": 0,
            "text": "Add a new comment"