I am trying to upload file to sharepoint via Postman. I have following settings:

URL:

https://{tenantID}.sharepoint/sites/{mySite}/_api/web/GetFolderByServerRelativeUrl('/sites/{mySite}/Shared Documents')/Files/add(url='test.png',overwrite=true)

Headers:

Authorization: Bearer {accessToken}
Accept: application/json;odata=verbose
Content-Type: application/octet-stream

uploaded file of type .png in binary form of Postman

Response:

 "error": {
        "code": "-2147024891, System.UnauthorizedAccessException",
        "message": {
            "lang": "en-US",
            "value": "Access denied."
        }
    }

I am trying to upload file to sharepoint via Postman. I have following settings:

URL:

https://{tenantID}.sharepoint/sites/{mySite}/_api/web/GetFolderByServerRelativeUrl('/sites/{mySite}/Shared Documents')/Files/add(url='test.png',overwrite=true)

Headers:

Authorization: Bearer {accessToken}
Accept: application/json;odata=verbose
Content-Type: application/octet-stream

uploaded file of type .png in binary form of Postman

Response:

 "error": {
        "code": "-2147024891, System.UnauthorizedAccessException",
        "message": {
            "lang": "en-US",
            "value": "Access denied."
        }
    }

• azure
• rest
• sharepoint
• upload

• Could you share the screenshot of your API permission blade and edit the question? – Pratik Jadhav Commented Mar 25 at 9:10
• Refer this Microsoft QnA Blog and let me know it works for you or not? @potato – Pratik Jadhav Commented Mar 25 at 10:47
• Please check below solution! – Pratik Jadhav Commented Mar 26 at 8:42
• Any update on the issue? @potato – Pratik Jadhav Commented Mar 28 at 5:33

2 Answers 2

I got the same error message, When I try to upload the file using SharePoint REST API :

To resolve the error, you have to add permission Full Control permission to your application.

Initially, I registered Single-Tenant Microsoft Entra ID Application and Added delegated type API permission like below and granted admin consent:

Configured Authentication tab like below:

Use below PowerShell script :

Connect-PnPOnline {tenant}.sharepoint -Interactive -ClientID <application_id>

Grant-PnPAzureADAppSitePermission -AppId "<client-id>" -Site "https://{tenant}.sharepoint/sites/{your-site}" -Permissions FullControl

Using delegated type, authorization_code flow which requires user-interaction. To get code, I ran below authorization request in browser:

https://login.microsoftonline/{Tenant-ID}/oauth2/v2.0/authorize?  
client_id=<CLIENT_ID>
&response_type=code  
&redirect_uri=http://localhost:58310
&response_mode=query  
&scope=https://{tenant}.sharepoint/.default
&state=12345

After successfully creating authorization_code, Generated access token using below parameters:

Headers:

Accept: application/json;odata=verbose
Content-Type: application/octet-stream

Body:

POST https://login.microsoftonline/<tenant-id>/oauth2/v2.0/token
Body: FormEncoded

client_id: <application-id>
scope: https://{tenant}.sharepoint/.default
grant_type: authorization_code
code: <authorization_code generated from browser>
redirect_uri: http://localhost:58310

Response:

Now, Use below endpoints to upload the .png file:

POST https://{tenantID}.sharepoint/sites/{mySite}/_api/web/GetFolderByServerRelativeUrl('/sites/{mySite}/Documents')/Files/add(url='<YOUR_FILE>',overwrite=true)

Response:

Also, I've verified from SharePoint App, .png is uploaded successfully.

Reference:

Connect-PnPOnline Blog

You need to register an app in SharePoint in order to authenticate against it. That app that you register needs to be given permissions to your SharePoint Online.

Here is the document for grant access to SharePoint app only

https://global-sharepoint/sharepoint-online/in-4-steps-access-sharepoint-online-data-using-postman-tool/