Note
Before any Apex callout can call an external site, that site must be registered in the Remote Site Settings page, or the callout fails. Salesforce prevents calls to unauthorized network addresses.
If the callout specifies a named credential as the endpoint, you don’t need to configure remote site settings. A named credential specifies the URL of a callout endpoint and its required authentication parameters in one definition. To set up named credentials, see “Define a Named Credential” in the Salesforce Help.
To learn more about the types of callouts, see:
- SOAP Services: Defining a Class from a WSDL Document
- Invoking HTTP Callouts
- Asynchronous Callouts for Long-Running Requests
Tip
Callouts enable Apex to invoke external web or HTTP services. Apex Web services allow an external application to invoke Apex methods through Web services.