Connect To SharePoint Online Site With App Only Authentication

I currently use CSOM / Username / Password and was hoping to switch to an App ID, butwhen I went to appregnew.aspx I noted the following message: "Starting April 2, 2026, Azure Access Control service (ACS) usage will be retired for SharePoint in Microsoft 365 and users will no longer be able to create or use Azure ACS principals to access SharePoint." Can you tell me can I use the App Principal method with an Entra ID, and can provide information on this? Thanks!

Nanddeep, question about your code - when I run the code I am getting the error System.Net.WebException: 'The remote server returned an error: (403) Forbidden.' The error is happening on the cc.ExecuteQuery() command. Any ideas?

The client credentials auth is soon be deprecated from MSFT. Its time for CBA (Cert Based Auth). thanks for sharing anyways

Hi Nanddeep, just wondering whether you have encountered this issue. My solution works when running on other PCs but it only worked once on my pc. I have verified the validity of the clientid and secret and they are not expired. On my PC, it consistently failed (Other than on 1 particular day) when I call GetAppOnlyAuthenticatedContext().

Hello Nanddeep, i try the code above to connect to SharePoint with ClientId And Client Secret, and i'm getting following error : Microsoft.IdentityModel.SecurityTokenService.RequestFailedException: Token request failed. ---> System.Net.WebException: The remote server returned an error: (401) Unauthorized. .....The error is thrown on the new AuthenticationManager().GetAppOnlyAuthenticatedContext codeline. Any advise would really appreciated

I would also like highlight that on my tenant two way authorization is enabled.

I tried above code. but getting remote server returning unauthorized 401 exception.

I am doing site association to hubsite with csom . For this I need to get sharepoint context with app plus user permission. how could be achieved this?

Hi, i connect with sucess the part 1 Connect to SharePoint Online. but now i need to create a frame in my home page aspx and inside the frame that appoint to sharepoint page and i would like that user will be logged come logged in as previously definedits. without necessity to put login and password again. its possible ?

Hi, what are the steps to be used if i need to create an App Only Authentication mechanism for a specific SharePoint and not for all the sharepoints in an organisation?

Hi, in this lines AppPermissionRequests> <AppPermissionRequest Scope="http://sharepoint/content/sitecollection/web/list" Right="Write"/> </AppPermissionRequests> can you explain how to include list syntax. It's only giving list names from root site

Thanks Nanddeep, Dharani has send you the code on u r email-id: [email protected], kindly check and let us know if you find any issue.We are waiting for your reply :).

Thanks sir for reply, I have tried with /web also, as I specify in my problem statement, I am getting fields but not items even items available, any possible reason? Ex: List list = cc.Web.Lists.GetByTitle(listName); cc.Load(list); if (list != null) { CamlQuery query = CamlQuery.CreateAllItemsQuery(100); ListItemCollection items = list.GetItems(query); cc.Load(items); cc.ExecuteQuery(); foreach (ListItem listItem in items) { Console.WriteLine(listItem.FieldValues["ID"]); } }

Sorry, but its not working in that case also (i.e. load and execute List and then iterate items) but count is always coming as zero, checked with other collection as well, where I a,m member of owner group. I have set scope like : <AppPermissionRequest Scope="https://mysite.sharepoint.com/teams/my-collection/list" Right="FullControl"/>. Do I need to check any rights, MFA or anything, kindly suggest.

We are the owner of SharePoint app and already give FullControl to collection. We are able to get the collection names, Field names of particular List but not ListItems. Sample code snipped for reference. using (var clientContext = new AuthenticationManager().GetAppOnlyAuthenticatedContext(siteUrl, appId, appSecret)) { CamlQuery caml = new CamlQuery(); caml.ViewXml = "<View><Query><OrderBy><FieldRef Name='Created' Ascending='false' /></OrderBy></Query><RowLimit>5</RowLimit></View>"; var requestItems = clientContext.Web.Lists.GetByTitle(listName).GetItems(caml); clientContext.Load(requestItems); clientContext.ExecuteQuery(); foreach (var item in requestItems) //Get 0 count even List contain values { Console.WriteLine(item["Title"]); } }

Does the app only permission have access to Search API ? which permissions should have? THanks

What is the point of adding ClientId and ClientSecret as keys in App.config and then using them directly in the managed code. Please let me know how to use them as keys in the code as I'm not able to do it.

Thank you..! Really great content with connecting and Store credentials in a secure wayalong with the other things.

Thanks for sharing

Thanks for sharing...

Nanddeep thanks for sharing. Just curious . How you are using PS generated password in CSOM

Please give me your contact details

Please let me know if you could give SharePoint Online Development Training?