diff --git a/README.md b/README.md
index db6e44d..862658f 100644
--- a/README.md
+++ b/README.md
@@ -1,37 +1,70 @@
# **API**
-
-## `currencies.register(currency)`
-Use this to register a currency, it is necessary in order to use every other function.
-
-## `currencies.set(pl_name, currency, value)`
-Use this to set a player's balance.
+### `currencies.register(currency, def)`
+Use this to register a currency, it is necessary to use every other function.
+`def` is a table containing the following values (it isn't demanded):
+```lua
+--[[
+{
+ min_value : number =
+ the smallest balance that a player can have.
-
+ max_value : number =
+ the biggest balance that a player can have.
+
+ negative_balance : bool =
+ if the balance can be less than 0.
+}
+]]
+```
-## `currencies.add(pl_name, currency, value)`
-Use this to increase a player's balance.
+
-
-
-## `currencies.sub(pl_name, currency, value)`
-Use this to decrease a player's balance.
-
-
-
-## `currencies.get(pl_name, currency)`
+### `currencies.get(currency, pl_name)`
Use this to get a player's balance.
-
+
+
+### `currencies.set(currency, pl_name, value)`
+Use this to set a player's balance.
+
+
+
+### `currencies.add(currency, pl_name, value)`
+Use this to increase a player's balance.
+
+
+
+### `currencies.sub(currency, pl_name, value)`
+Use this to decrease a player's balance.
+
+
+
+### `currencies.transfer(currency, from_pl_name, to_pl_name, amount)`
+Use this to subtract `amount` money `from_pl_name` and add them to `to_pl_name`.
+
+
+
+### `currencies.exchange(currency, from_pl_name, from_amount, to_pl_name, to_amount)`
+Use this to subtract `from_amount` from `from_pl_name` and add `to_amount` to `to_pl_name`.
+
+
+
+### `currencies.exists(currency)`
+Use this to check if a currency has been registered.
+
+
+
+
## Example
```lua
-currencies.register("skywars_money")
+currencies.register("skywars_money", {min_value = 250})
-currencies.add("Giov4", "skywars_money", 300)
-currencies.sub("Giov4", "skywars_money", 100)
+currencies.add("skywars_money", "Giov4", 300)
+currencies.sub("skywars_money", "Giov4", 100)
-local balance = currencies.get("Giov4", "skywars_money")
-print(balance) -- output: 200
+local balance = currencies.get("skywars_money", "Giov4")
+print(balance) -- output: 250
```