diff --git a/specifications/Makefile b/specifications/Makefile
new file mode 100644
index 0000000..9ec42fb
--- /dev/null
+++ b/specifications/Makefile
@@ -0,0 +1,7 @@
+all: commands.png
+
+clean:
+	rm -f commands.png
+
+commands.png: commands.gv
+	dot -Tpng -ocommands.png commands.gv
diff --git a/specifications/commands.gv b/specifications/commands.gv
new file mode 100644
index 0000000..597ec11
--- /dev/null
+++ b/specifications/commands.gv
@@ -0,0 +1,24 @@
+digraph finite_state_machine {
+        rankdir=LR;
+        node [shape = doublecircle, fixedsize = true, width = 1.2, height = 1.2]; standard;
+        node [shape = circle];
+        standard -> standard [ label = "any key" ];
+        standard -> "command\nmode" [ label = "hotkey" ];
+        "command\nmode" -> standard [ label = "single key command" ];
+        "command\nmode" -> standard [ label = "invalid key" ];
+
+        "command\nmode" -> "macro\ncommand" [ label = "m" ];
+        "macro\ncommand" -> "macro\ndefinition" [ label = "macro key" ];
+        "macro\ndefinition" -> "macro\ndefinition" [ label = "any key" ];
+        "macro\ndefinition" -> standard [ label = "hotkey" ];
+
+        "command\nmode" -> "macro\ndelete" [ label = "M" ];
+        "macro\ndelete" -> standard [ label = "macro key" ];
+
+        "command\nmode" -> "complex\ncommand" [ label = "multi key command" ];
+        "complex\ncommand" -> "complex\ncommand" [ label = "any key" ];
+        "complex\ncommand" -> standard [ label = "hotkey" ];
+        "complex\ncommand" -> standard [ label = "invalid key" ];
+}
+
+