staempfli/magento2-module-checkout-newsletter-subscription

<?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/guest-carts/:cartId/newsletter-subscribe" method="PUT">
        <service class="Staempfli\CheckoutNewsletterSubscription\Api\NewsletterSubscriptionManagementInterface" method="subscribe"/>
        <resources>
            <resource ref="anonymous" />
        </resources>
    </route>
    <route url="/V1/carts/mine/newsletter-subscribe" method="PUT">
        <service class="Staempfli\CheckoutNewsletterSubscription\Api\NewsletterSubscriptionManagementInterface" method="subscribe"/>
        <resources>
            <resource ref="self" />
        </resources>
        <data>
            <parameter name="cartId" force="true">%cart_id%</parameter>
        </data>
    </route>
</routes>