diff --git a/du7/snake/world.h b/du7/snake/world.h
new file mode 100644
index 0000000..e7a3fdb
--- /dev/null
+++ b/du7/snake/world.h
@@ -0,0 +1,122 @@
+#ifndef _WORLD_H_
+#define _WORLD_H_
+
+#include <curses.h>
+
+/**
+ * World represented as a rectangular matrix of colorful characters.
+ * 
+ * Point [0,0] is displayed the upper left corner of the screen.
+ * 
+ */
+
+enum event_type {
+    EVENT_START,
+    EVENT_TIMEOUT,
+    EVENT_KEY,
+    EVENT_MOUSE,
+    EVENT_RESIZE,
+    EVENT_ESC,
+    EVENT_END,
+};
+
+struct event {
+    /**
+     * Last width of the screen.
+     */
+    int width;
+    /**
+     * Last height of the screen.
+     */
+    int height;
+    /**
+     * Last pressed key or Curses event.
+     *
+     * Special event  values:
+     * ERR if timeout,
+     * KEY_RESIZE if screen resize
+     * KEY_EVENT, other event,
+     * KEY_MOUSE, mouse clicked
+     *
+     * Key values:
+     *
+     * ' ' Space
+     * KEY_DOWN Arrow down
+     * KEY_UP Arrow up
+     * KEY_LEFT Arrow left
+     * KEY_RIGHT Arrow right
+     * KEY_A1 Upper left of keypad
+     * KEY_A3 Upper right of keypad
+     * KEY_B2 Center of keypad
+     * KEY_C1 Lower left of keypad
+     * KEY_C3 Lower right of keypad
+     *
+     * KEY_ENTER
+     * KEY_BACKSPACE
+     */
+    int key;
+    int alt_key;
+    enum event_type type;
+    int mouse_x;
+    int mouse_y;
+    int mouse_left;
+    int mouse_right;
+    int mouse_middle;
+    long int time_ms;
+};
+
+/**
+ * Sets cell to a state.
+ * @param event 
+ * @param x coordinate of cell
+ * @param y coordinate of cell
+ * @param new state of the cell
+ */
+void set_cell(int character,int x,int y);
+
+/**
+ * COLOR_BLACK   0
+ * COLOR_RED     1
+ * COLOR_GREEN   2
+ * COLOR_YELLOW  3
+ * COLOR_BLUE    4
+ * COLOR_MAGENTA 5
+ * COLOR_CYAN    6
+ * COLOR_WHITE   7
+ */
+
+#define COLOR_COUNT 8
+
+void set_color_cell(int character,int x,int y,short front_color,short back_color);
+
+
+/**
+ *
+ * @param event
+ * @param number of commandline arguments
+ * @param init_world
+ * @param destroy_world
+ *
+ * void init_world(struct event* w);
+ * Initializes user state.
+ * Free user state.
+ * @param event
+ */
+
+int start_world(void* (*init_game)(),int (*world_event)(struct event* event,void* game),void (*destroy_game)(void* game));
+/**
+ * Set timeout interval in miliseconds
+ */
+void game_speed(int value);
+
+/*
+ * Prints a message in screen on a position x,y
+ */
+
+void set_message(const char* message,int x,int y);
+/*
+ * Clears screen
+ */
+void clear_screen();
+
+#endif