diff --git a/reveal.lua b/reveal.lua
new file mode 100644
index 0000000..38d1ad0
--- /dev/null
+++ b/reveal.lua
@@ -0,0 +1,141 @@
+local revealed_cache = {}
+
+
+local function item_has_groups(item_groups, groups)
+	for i = 1, #groups do
+		local group = groups[i]
+		if not item_groups[group] then
+			return
+		end
+	end
+	return true
+end
+
+
+local function revealed_show_recipe(recipe, playername)
+	if not revealed_cache[playername] then
+		revealed_cache[playername] = {}
+	end
+	if revealed_cache[playername][recipe] then
+		return true
+	end
+
+  local reg_items = minetest.registered_items
+	local revealed = doc.data.players[playername].stored_data.revealed
+	for _, item in pairs(recipe.items) do
+		local is_revealed_item = false
+		if item:sub(1,6) == "group:" then
+			local groups = item:sub(7):split(",")
+			for cid, items in pairs(revealed) do
+				for revealed_item in pairs(items) do
+					if reg_items[revealed_item] and item_has_groups(reg_items[revealed_item].groups, groups) then
+						is_revealed_item = true
+						break
+					end
+				end
+				if is_revealed_item then
+					break
+				end
+			end
+		else
+			for cid, items in pairs(revealed) do
+				if items[item] then
+					is_revealed_item = true
+					break
+				end
+			end
+		end
+
+		if not is_revealed_item then
+			return false
+		end
+	end
+	revealed_cache[playername][recipe] = true
+	return true
+end
+
+
+local orig_execute_search = sfcg.execute_search
+local orig_get_usages = sfcg.get_usages
+local orig_get_recipes = sfcg.get_recipes
+local orig_mark_entry_as_revealed = doc.mark_entry_as_revealed
+
+function sfcg.get_usages(data, item)
+  local recipes = orig_get_usages(data, item)
+  if not recipes then
+    return
+  end
+
+  local filtered = {}
+  for _, recipe in ipairs(recipes) do
+    if revealed_show_recipe(recipe, data.playername) then
+      table.insert(filtered, recipe)
+    end
+  end
+  if #filtered > 0 then
+    return filtered
+  end
+end
+
+function sfcg.get_recipes(data, item)
+  local recipes = orig_get_recipes(data, item)
+  if not recipes then
+    return
+  end
+
+  local filtered = {}
+  for _, recipe in ipairs(recipes) do
+    if revealed_show_recipe(recipe, data.playername) then
+      table.insert(filtered, recipe)
+    end
+  end
+  if #filtered > 0 then
+    return filtered
+  end
+end
+
+function sfcg.execute_search(data)
+  -- Only needed if doc is an optional dependency
+  --
+  -- if not doc.data.players[data.playername] then
+  -- 	-- Hack. craftguide is loaded before doc mod. Therefore doc is not initialized yet
+  -- 	data.items = {}
+  -- 	minetest.after(0, sfcg.execute_search, data)
+  -- 	return
+  -- end
+
+  orig_execute_search(data)
+
+  local filtered_items = {}
+  for _, item in ipairs(data.items) do
+    if sfcg.get_usages(data, item) or
+        sfcg.get_recipes(data, item) then
+      table.insert(filtered_items, item)
+    end
+  end
+  data.items = filtered_items
+end
+
+-- Update sfinv inventory once in globalstep, if something revealed
+local async_update_users = {}
+local function async_update()
+  for playername, _ in pairs(async_update_users) do
+    sfcg.update_for_player(playername)
+    async_update_users[playername] = nil
+  end
+end
+
+function doc.mark_entry_as_revealed(playername, category_id, entry_id)
+  if not doc.entry_revealed(playername, category_id, entry_id) then
+    orig_mark_entry_as_revealed(playername, category_id, entry_id)
+    if not next(async_update_users) then
+      minetest.after(0, async_update)
+      async_update_users[playername] = true
+    end
+  end
+end
+
+
+minetest.register_on_leaveplayer(function(player)
+	revealed_cache[player:get_player_name()] = nil
+end)
\ No newline at end of file