Can someone please help me out in overwriting the REST API with Magento 2.3 for customer registeration, please describe with example.
You need to create a webapi.xml file under etc folder within your custom module
<?xml version="1.0"?> <routes xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Webapi:etc/webapi.xsd"> <route url="/V1/customers" method="POST"> <service class="VendorName\ModuleName\Api\AccountManagementInterface" method="createAccount"/> <resources> <resource ref="anonymous"/> </resources> </route> </routes>
You need to define interfaces same as AccountManagementInterface of customer module. I hope it will work. Let me know if you need further help :)
If you want just add some custom data to response, there is no reason to do some overrides. You can archive this with use of extension attributes there I provided an example (about quote item, but for Customer idea should be the same). If you don't know about extension attributes there a good starting point.