Yes you can build your APIs through Odoo's XMLRPC point located at this URL /xmlrpc/2/object

here is an example of an XMLRPC request from a PHP file

	$url = "http://demo3.odoo.com";
	$db = "demo3";
	$username = "admin";
	$password = "admin";
	$end_point = $url . "/xmlrpc/2/object";

        $model = ripcord::client($end_point);

        $result = $model->execute_kw(
		$db,$uid,$password,"res.partner","search_read",
		array(
			array(
				// array("id","=",1),
				array("name","ilike","ali")
			),
		),
		array('fields'=>array("name","phone","email"))
	);

	echo json_encode($result);

You can find a full example here if you want.

Happy to help :) an upvote will be awesome