diff --git a/README.txt b/README.txt
index 6ed2d36..3273b9d 100644
--- a/README.txt
+++ b/README.txt
@@ -25,6 +25,48 @@ There is also 1 friendly mob:
 - The sheep spawns on grass. You can get wool from it when you rightclick
   it and meat if you kill it. Meat can bee cooked in the furnace to eat it.
 
+For developers:
+This mod add some functions that you can use in other mods:
+1. mobs:register_monster(name, def)
+	This adds a monster to Minetest that will attack the player
+	"name" is the name of the monster ("[modname]:[monstername]")
+	"def" is a table with the following values:
+		hp_max: same is in minetest.register_entity()
+		physical: same is in minetest.register_entity()
+		collisionbox: same is in minetest.register_entity()
+		visual: same is in minetest.register_entity()
+		visual_size: same is in minetest.register_entity()
+		textures: same is in minetest.register_entity()
+		makes_footstep_sound: same is in minetest.register_entity()
+		view_range: the range in that the monster will see the player
+			and follow him
+		walk_velocity: the velocity when the monster is walking arround
+		run_velocity: the velocity when the monster is attacking a player
+		damage: the damage per second
+		light_resistant: light wont cause damage on day
+		drop: the drop item of the monster
+		drop_count: the number of items that are dropped
+		armor: the armor (integer)(3=lowest; 1=highest)(fleshy group is used)
+		drawtype: "front" or "side"
+2. mobs:register_animal(name, def)
+	This adds a animal to Minetest that will just walk arround
+	"name" is the name of the monster ("[modname]:[animalname]")
+	"def" is the same table as in register_monster but without these values:
+		view_range
+		run_velocity
+		damage
+		light_resistant
+		armor
+	and it also has the field
+		on_rightclick: its same as in minetest.register_entity()
+3. mobs:register_spawn(name, nodes, max_light, min_light)
+	This function adds the spawning of an animal (without it the
+		registered animals and monster wont spawn!)
+	"name" is the name of the animal/monster
+	"nodes" is a list of nodenames on that the animal/monster can spawn
+	"max_light" is the maximum of light
+	"min_light" is the minimum of light
+
 License:
 Sourcecode: WTFPL (see below)
 Grahpics: WTFPL (see below)