diff --git a/hswaw/proto/checkinator.proto b/hswaw/proto/checkinator.proto
new file mode 100644
index 0000000..882083c
--- /dev/null
+++ b/hswaw/proto/checkinator.proto
@@ -0,0 +1,19 @@
+syntax = "proto3";
+package hswaw;
+option go_package = "code.hackerspace.pl/hscloud/hswaw/proto";
+
+message LeasifierLeasesRequest {
+};
+
+message LeasifierLease {
+    string physical_address = 1;
+    string ip_address = 2;
+};
+
+message LeasifierLeasesResponse {
+    repeated LeasifierLease leases = 1;
+};
+
+service Leasifier {
+    rpc Leases(LeasifierLeasesRequest) returns (LeasifierLeasesResponse);
+};