REST (Representational State Transfer) is an architectural style that allows you to interact with SharePoint data using standard HTTP requests. SharePoint provides a RESTful web service that enables developers to access and manipulate SharePoint resources such as lists, items, and libraries in a straightforward and flexible manner.

Key Features of SharePoint REST API

• Standard HTTP Methods: Supports standard HTTP methods like GET, POST, PUT, and DELETE to perform CRUD operations.

• JSON Format: Data is exchanged in JSON format, making it easy to work with in JavaScript and other programming languages.

• OData Protocol: Supports OData (Open Data Protocol), allowing for rich querying capabilities, including filtering, sorting, and pagination.

• Cross-Domain Requests: Can be accessed from client-side code in browser scenarios using CORS (Cross-Origin Resource Sharing).

Common Use Cases

• Retrieving list items and document libraries.

• Creating new list items or libraries.

• Updating existing items.

• Deleting items from lists or libraries.

• Executing complex queries and fetching related data.

Basic Example

To retrieve items from a SharePoint list using the REST API, you would perform a GET request to the following endpoint:

GET /_api/web/lists/getbytitle('ListName')/items

This will return a JSON array of items in the specified list.

Authentication

Accessing the REST API in SharePoint typically requires authentication. Depending on the environment (on-premises or SharePoint Online), you may use:

• OAuth tokens (for SharePoint Online)

• NTLM or Kerberos (for on-premises SharePoint)

• [Microsoft Documentation on SharePoint REST API](https://docs.microsoft.com/en-us/sharepoint/dev/sp-add-ins/working-with-lists-and-list-items-with-rest)

• [OData Documentation](https://www.odata.org/)

• https://docs.microsoft.com/en-us/sharepoint/dev/sp-add-ins/get-to-know-the-sharepoint-rest-service

Example REST APIs:

• Microsoft Graph API

• https://docs.microsoft.com/en-us/sharepoint/dev/apis/alm-api-for-spfx-add-ins

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Tools:

• Postman

• SoapUI