register the adapter instead of the @login endpoint

src/pas/plugins/authomatic/services/configure.zcml

@@ -5,13 +5,10 @@
 
   <include package="plone.restapi" />
   <!-- List authentication options -->
-  <plone:service
-      method="GET"
-      factory=".login.Get"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
-      permission="zope.Public"
-      name="@login"
-      />
+  <adapter
+    factory=".login.AuthomaticLoginProviders"
+    name="pas-plugins-authomatic-providers"
+    />
 
   <!-- Authomatic authentication services -->
   <plone:service

src/pas/plugins/authomatic/services/login.py

@@ -1,40 +1,29 @@
 from pas.plugins.authomatic.utils import authomatic_cfg
-from plone.restapi.services import Service
-from typing import Dict
-from typing import List
+from plone.base.interfaces import IPloneSiteRoot
+from plone.restapi.interfaces import IExternalLoginProviders
+from zope.component import adapter
+from zope.interface import implementer
 
 
-class Get(Service):
-    """List available login options for the site."""
+@adapter(IPloneSiteRoot)
+@implementer(IExternalLoginProviders)
+class AuthomaticLoginProviders:
+    def __init__(self, context):
+        self.context = context
 
-    @staticmethod
-    def list_plugins() -> List[Dict]:
-        """List all configured Authomatic plugins.
-
-        :returns: List of login options.
-        """
-        try:
-            providers = authomatic_cfg()
-        except KeyError:
-            # Authomatic is not configured
-            providers = {}
-        plugins = []
+    def get_providers(self):
+        options = []
+        providers = authomatic_cfg()
         for provider_id, provider in providers.items():
             entry = provider.get("display", {})
             title = entry.get("title", provider_id)
-            plugins.append(
-                dict(
-                    id=provider_id,
-                    plugin="authomatic",
-                    title=title,
-                )
+            options.append(
+                {
+                    "id": provider_id,
+                    "plugin": "authomatic",
+                    "title": title,
+                    "url": f"{self.context.absolute_url()}/@login-authomatic/${provider_id}",
+                }
             )
-        return plugins
-
-    def reply(self) -> Dict[str, List[Dict]]:
-        """List login options available for the site.
 
-        :returns: Login options information.
-        """
-        providers = self.list_plugins()
-        return {"options": providers}
+        return {"options": options}