diff --git a/provider_client.go b/provider_client.go
index 17fefa0..7f8b892 100644
--- a/provider_client.go
+++ b/provider_client.go
@@ -6,15 +6,19 @@
 // providing whatever authentication credentials are required.
 type ProviderClient struct {
 
-	// Options remembers the original authentication parameters, if reauthentication is enabled.
-	Options AuthOptions
+	// IdentityEndpoint is the front door to an openstack provider.
+	// Generally this will be populated when you authenticate.
+	// It should be the *root* resource of the identity service, not of a specific identity version.
+	IdentityEndpoint string
+
+	// Reauthenticate is a callback that will be invoked to reauthenticate this client, if reauthentication is enabled.
+	Reauthenticate func() error
 
 	// TokenID is the most recently valid token issued.
 	TokenID string
 }
 
-// AuthenticatedHeaders returns a map of HTTP headers that are common for all authenticated service
-// requests.
+// AuthenticatedHeaders returns a map of HTTP headers that are common for all authenticated service requests.
 func (client *ProviderClient) AuthenticatedHeaders() map[string]string {
 	return map[string]string{"X-Auth-Token": client.TokenID}
 }
diff --git a/service_client.go b/service_client.go
index 2dccde1..cca5a74 100644
--- a/service_client.go
+++ b/service_client.go
@@ -5,14 +5,15 @@
 // ServiceClient stores details required to interact with a specific service API implemented by a provider.
 // Generally, you'll acquire these by calling the appropriate `New` method on a ProviderClient.
 type ServiceClient struct {
-	// ProviderClient is a reference to the provider that implements this service.
-	ProviderClient
+	// Provider is a reference to the provider that implements this service.
+	Provider *ProviderClient
 
 	// Endpoint is the base URL of the service's API, acquired from a service catalog.
+	// It should NOT end with a /.
 	Endpoint string
 }
 
 // ServiceURL constructs a URL for a resource belonging to this provider.
 func (client *ServiceClient) ServiceURL(parts ...string) string {
-	return client.Endpoint + strings.Join(parts, "/")
+	return client.Endpoint + "/" + strings.Join(parts, "/")
 }