diff --git a/Keys/Constraints.hs b/Keys/Constraints.hs
--- a/Keys/Constraints.hs
+++ b/Keys/Constraints.hs
@@ -18,11 +18,14 @@
 import Data.Data
 import Data.String
 import Data.Monoid
+import Control.Monad
 import Control.DeepSeq
 import Data.SafeCopy
 import Data.Serialize
 import Data.Text.Encoding
 import Data.Hashable
+import Data.Aeson
+import qualified Data.Aeson as Aeson
 
 -- | Text with a maximum of 128 characters
 newtype Text128 = Text128 T.Text deriving(Eq, Data, Ord, Read, Show, Typeable, IsString, Monoid, NFData)
@@ -88,6 +91,24 @@
 instance SafeCopy Text4096 where putCopy (Text4096 t) = putCopy t
                                  getCopy = contain $ Text4096 `fmap` safeGet
 
+instance FromJSON Text128 where parseJSON (Aeson.String s) = return $ t128 s
+                                parseJSON _ = mzero
+instance FromJSON Text256 where parseJSON (Aeson.String s) = return $ t256 s
+                                parseJSON _ = mzero
+instance FromJSON Text512 where parseJSON (Aeson.String s) = return $ t512 s
+                                parseJSON _ = mzero
+instance FromJSON Text1024 where parseJSON (Aeson.String s) = return $ t1024 s
+                                 parseJSON _ = mzero
+instance FromJSON Text2048 where parseJSON (Aeson.String s) = return $ t2048 s
+                                 parseJSON _ = mzero
+instance FromJSON Text4096 where parseJSON (Aeson.String s) = return $ t4096 s
+                                 parseJSON _ = mzero
+instance ToJSON Text128 where toJSON s = Aeson.String (getTxt s)
+instance ToJSON Text256 where toJSON s = Aeson.String (getTxt s)
+instance ToJSON Text512 where toJSON s = Aeson.String (getTxt s)
+instance ToJSON Text1024 where toJSON s = Aeson.String (getTxt s)
+instance ToJSON Text2048 where toJSON s = Aeson.String (getTxt s)
+instance ToJSON Text4096 where toJSON s = Aeson.String (getTxt s)
 
 t128 :: T.Text -> Text128
 t128 = Text128 . T.take 128
diff --git a/special-keys.cabal b/special-keys.cabal
--- a/special-keys.cabal
+++ b/special-keys.cabal
@@ -1,5 +1,5 @@
 name:                special-keys
-version:             0.1.0.1
+version:             0.1.0.2
 synopsis:            Simple data types that help me here and there. 
 description:         Datatypes that I use as keys to index other data types. Here you will find a wrap of UUID and also constraints on Text so that it never exceeds a given number of characters.
 license:             BSD3
@@ -28,4 +28,5 @@
                     primitive >= 0.5,
                     bytestring >= 0.10,
                     uuid >= 1.2,
-                    mwc-random >= 0.12
+                    mwc-random >= 0.12,
+                    aeson >= 0.6.1.0