diff --git a/z3950-api/src/main/java/org/xbib/z3950/api/ClientProvider.java b/z3950-api/src/main/java/org/xbib/z3950/api/ClientProvider.java
index 7e58b62..79985e0 100644
--- a/z3950-api/src/main/java/org/xbib/z3950/api/ClientProvider.java
+++ b/z3950-api/src/main/java/org/xbib/z3950/api/ClientProvider.java
@@ -1,5 +1,9 @@
 package org.xbib.z3950.api;
 
+/**
+ * Client provider.
+ * @param <C> the client type parameter
+ */
 public interface ClientProvider<C extends Client> {
 
     C getClient();
diff --git a/z3950-api/src/main/java/org/xbib/z3950/api/package-info.java b/z3950-api/src/main/java/org/xbib/z3950/api/package-info.java
new file mode 100644
index 0000000..d9e5f87
--- /dev/null
+++ b/z3950-api/src/main/java/org/xbib/z3950/api/package-info.java
@@ -0,0 +1,4 @@
+/**
+ * API for Z39.50 applications.
+ */
+package org.xbib.z3950.api;