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+              GNU GENERAL PUBLIC LICENSE
+                Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
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+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+              END OF TERMS AND CONDITIONS
+
+     How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<http://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<http://www.gnu.org/philosophy/why-not-lgpl.html>.
diff --git a/server/Setup.hs b/server/Setup.hs
new file mode 100644
index 0000000..9a994af
--- /dev/null
+++ b/server/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/server/server.cabal b/server/server.cabal
new file mode 100644
index 0000000..2e1f7be
--- /dev/null
+++ b/server/server.cabal
@@ -0,0 +1,47 @@
+name:                server
+version:             0.0.1
+license:             GPL-3
+license-file:        LICENSE
+author:              Joris Guyonvarch
+maintainer:          joris@guyonvarch.me
+category:            Web
+build-type:          Simple
+cabal-version:       >=1.10
+
+executable server
+  main-is:             Main.hs
+  ghc-options:         -Wall -Werror
+  build-depends:       aeson
+                     , base >=4.9 && <4.11
+                     , base64-bytestring
+                     , blaze-builder
+                     , blaze-html
+                     , bytestring
+                     , clay
+                     , clientsession
+                     , common
+                     , config-manager
+                     , containers
+                     , cookie
+                     , email-validate
+                     , filepath
+                     , http-conduit
+                     , http-types
+                     , lens
+                     , monad-logger
+                     , mtl
+                     , parsec
+                     , process
+                     , resourcet
+                     , random
+                     , scotty
+                     , sqlite-simple
+                     , text
+                     , time
+                     , transformers
+                     , unordered-containers
+                     , uuid
+                     , wai
+                     , wai-middleware-static
+  hs-source-dirs:      src
+  default-language:    Haskell2010
diff --git a/server/src/Conf.hs b/server/src/Conf.hs
new file mode 100644
index 0000000..26c5c28
--- /dev/null
+++ b/server/src/Conf.hs
@@ -0,0 +1,39 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Conf
+  ( get
+  , Conf(..)
+  ) where
+
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified Data.ConfigManager as Conf
+import Data.Time.Clock (NominalDiffTime)
+
+import Common.Model (Currency(..))
+
+data Conf = Conf
+  { hostname :: Text
+  , port :: Int
+  , signInExpiration :: NominalDiffTime
+  , currency :: Currency
+  , noReplyMail :: Text
+  , https :: Bool
+  } deriving Show
+
+get :: FilePath -> IO Conf
+get path = do
+  conf <-
+    (flip fmap) (Conf.readConfig path) (\configOrError -> do
+      conf <- configOrError
+      Conf <$>
+        Conf.lookup "hostname" conf <*>
+        Conf.lookup "port" conf <*>
+        Conf.lookup "signInExpiration" conf <*>
+        fmap Currency (Conf.lookup "currency" conf) <*>
+        Conf.lookup "noReplyMail" conf <*>
+        Conf.lookup "https" conf
+    )
+  case conf of
+    Left msg -> error (T.unpack msg)
+    Right c -> return c
diff --git a/server/src/Controller/Category.hs b/server/src/Controller/Category.hs
new file mode 100644
index 0000000..d6ed2f2
--- /dev/null
+++ b/server/src/Controller/Category.hs
@@ -0,0 +1,53 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Controller.Category
+  ( create
+  , edit
+  , delete
+  ) where
+
+import Control.Monad.IO.Class (liftIO)
+import Network.HTTP.Types.Status (ok200, badRequest400)
+import qualified Data.Text.Lazy as TL
+import Web.Scotty hiding (delete)
+
+import qualified Common.Message as Message
+import qualified Common.Message.Key as Key
+import Common.Model (CategoryId, CreateCategory(..), EditCategory(..))
+
+import Json (jsonId)
+import qualified Model.Category as Category
+import qualified Model.PaymentCategory as PaymentCategory
+import qualified Model.Query as Query
+import qualified Secure
+
+create :: CreateCategory -> ActionM ()
+create (CreateCategory name color) =
+  Secure.loggedAction (\_ ->
+    (liftIO . Query.run $ Category.create name color) >>= jsonId
+  )
+
+edit :: EditCategory -> ActionM ()
+edit (EditCategory categoryId name color) =
+  Secure.loggedAction (\_ -> do
+    updated <- liftIO . Query.run $ Category.edit categoryId name color
+    if updated
+      then status ok200
+      else status badRequest400
+  )
+
+delete :: CategoryId -> ActionM ()
+delete categoryId =
+  Secure.loggedAction (\_ -> do
+    deleted <- liftIO . Query.run $ do
+      paymentCategories <- PaymentCategory.listByCategory categoryId
+      if null paymentCategories
+        then Category.delete categoryId
+        else return False
+    if deleted
+      then
+        status ok200
+      else do
+        status badRequest400
+        text . TL.fromStrict $ Message.get Key.Category_NotDeleted
+  )
diff --git a/server/src/Controller/Income.hs b/server/src/Controller/Income.hs
new file mode 100644
index 0000000..148b713
--- /dev/null
+++ b/server/src/Controller/Income.hs
@@ -0,0 +1,48 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Controller.Income
+  ( create
+  , editOwn
+  , deleteOwn
+  ) where
+
+import Control.Monad.IO.Class (liftIO)
+import Network.HTTP.Types.Status (ok200, badRequest400)
+import qualified Data.Text.Lazy as TL
+import Web.Scotty
+
+import qualified Common.Message as Message
+import qualified Common.Message.Key as Key
+import Common.Model (CreateIncome(..), EditIncome(..), IncomeId, User(..))
+
+import Json (jsonId)
+import qualified Model.Income as Income
+import qualified Model.Query as Query
+import qualified Secure
+
+create :: CreateIncome -> ActionM ()
+create (CreateIncome date amount) =
+  Secure.loggedAction (\user ->
+    (liftIO . Query.run $ Income.create (_user_id user) date amount) >>= jsonId
+  )
+
+editOwn :: EditIncome -> ActionM ()
+editOwn (EditIncome incomeId date amount) =
+  Secure.loggedAction (\user -> do
+    updated <- liftIO . Query.run $ Income.editOwn (_user_id user) incomeId date amount
+    if updated
+      then status ok200
+      else status badRequest400
+  )
+
+deleteOwn :: IncomeId -> ActionM ()
+deleteOwn incomeId =
+  Secure.loggedAction (\user -> do
+    deleted <- liftIO . Query.run $ Income.deleteOwn user incomeId
+    if deleted
+      then
+        status ok200
+      else do
+        status badRequest400
+        text . TL.fromStrict $ Message.get Key.Income_NotDeleted
+  )
diff --git a/server/src/Controller/Index.hs b/server/src/Controller/Index.hs
new file mode 100644
index 0000000..8473c5c
--- /dev/null
+++ b/server/src/Controller/Index.hs
@@ -0,0 +1,86 @@
+module Controller.Index
+  ( get
+  , signOut
+  ) where
+
+import Control.Monad.IO.Class (liftIO)
+import Data.Text (Text)
+import Data.Time.Clock (getCurrentTime, diffUTCTime)
+import Network.HTTP.Types.Status (ok200)
+import Prelude hiding (error)
+import Web.Scotty hiding (get)
+
+import qualified Common.Message as Message
+import Common.Message.Key (Key)
+import qualified Common.Message.Key as Key
+import Common.Model (InitResult(..), User(..))
+
+import Conf (Conf(..))
+import Model.Init (getInit)
+import qualified LoginSession
+import qualified Model.Query as Query
+import qualified Model.SignIn as SignIn
+import qualified Model.User as User
+import Secure (getUserFromToken)
+import View.Page (page)
+
+get :: Conf -> Maybe Text -> ActionM ()
+get conf mbToken = do
+  initResult <- case mbToken of
+    Just token -> do
+      userOrError <- validateSignIn conf token
+      case userOrError of
+        Left errorKey ->
+          return . InitEmpty . Left . Message.get $ errorKey
+        Right user ->
+          liftIO . Query.run . fmap InitSuccess $ getInit user conf
+    Nothing -> do
+      mbLoggedUser <- getLoggedUser
+      case mbLoggedUser of
+        Nothing ->
+          return . InitEmpty . Right $ Nothing
+        Just user ->
+          liftIO . Query.run . fmap InitSuccess $ getInit user conf
+  html $ page initResult
+
+validateSignIn :: Conf -> Text -> ActionM (Either Key User)
+validateSignIn conf textToken = do
+  mbLoggedUser <- getLoggedUser
+  case mbLoggedUser of
+    Just loggedUser ->
+      return . Right $ loggedUser
+    Nothing -> do
+      mbSignIn <- liftIO . Query.run $ SignIn.getSignIn textToken
+      now <- liftIO getCurrentTime
+      case mbSignIn of
+        Nothing ->
+          return . Left $ Key.SignIn_LinkInvalid
+        Just signIn ->
+          if SignIn.isUsed signIn
+            then
+              return . Left $ Key.SignIn_LinkUsed
+            else
+              let diffTime = now `diffUTCTime` (SignIn.creation signIn)
+              in  if diffTime > signInExpiration conf
+                    then
+                      return . Left $ Key.SignIn_LinkExpired
+                    else do
+                      LoginSession.put conf (SignIn.token signIn)
+                      mbUser <- liftIO . Query.run $ do
+                        SignIn.signInTokenToUsed . SignIn.id $ signIn
+                        User.get . SignIn.email $ signIn
+                      return $ case mbUser of
+                        Nothing -> Left Key.Secure_Unauthorized
+                        Just user -> Right user
+
+getLoggedUser :: ActionM (Maybe User)
+getLoggedUser = do
+  mbToken <- LoginSession.get
+  case mbToken of
+    Nothing ->
+      return Nothing
+    Just token -> do
+      liftIO . Query.run . getUserFromToken $ token
+
+signOut :: Conf -> ActionM ()
+signOut conf = LoginSession.delete conf >> status ok200
diff --git a/server/src/Controller/Payment.hs b/server/src/Controller/Payment.hs
new file mode 100644
index 0000000..dc10311
--- /dev/null
+++ b/server/src/Controller/Payment.hs
@@ -0,0 +1,58 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Controller.Payment
+  ( list
+  , create
+  , editOwn
+  , deleteOwn
+  ) where
+
+import Control.Monad.IO.Class (liftIO)
+import Network.HTTP.Types.Status (ok200, badRequest400)
+import Web.Scotty
+
+import Common.Model (PaymentId, User(..), CreatePayment(..), EditPayment(..))
+
+import Json (jsonId)
+import qualified Model.Payment as Payment
+import qualified Model.PaymentCategory as PaymentCategory
+import qualified Model.Query as Query
+import qualified Secure
+
+list :: ActionM ()
+list =
+  Secure.loggedAction (\_ ->
+    (liftIO . Query.run $ Payment.list) >>= json
+  )
+
+create :: CreatePayment -> ActionM ()
+create (CreatePayment name cost date category frequency) =
+  Secure.loggedAction (\user ->
+    (liftIO . Query.run $ do
+      PaymentCategory.save name category
+      Payment.create (_user_id user) name cost date frequency
+    ) >>= jsonId
+  )
+
+editOwn :: EditPayment -> ActionM ()
+editOwn (EditPayment paymentId name cost date category frequency) =
+  Secure.loggedAction (\user -> do
+    updated <- liftIO . Query.run $ do
+      edited <- Payment.editOwn (_user_id user) paymentId name cost date frequency
+      _ <- if edited
+        then PaymentCategory.save name category >> return ()
+        else return ()
+      return edited
+    if updated
+      then status ok200
+      else status badRequest400
+  )
+
+deleteOwn :: PaymentId -> ActionM ()
+deleteOwn paymentId =
+  Secure.loggedAction (\user -> do
+    deleted <- liftIO . Query.run $ Payment.deleteOwn (_user_id user) paymentId
+    if deleted
+      then status ok200
+      else status badRequest400
+  )
diff --git a/server/src/Controller/SignIn.hs b/server/src/Controller/SignIn.hs
new file mode 100644
index 0000000..0086fa5
--- /dev/null
+++ b/server/src/Controller/SignIn.hs
@@ -0,0 +1,47 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Controller.SignIn
+  ( signIn
+  ) where
+
+import Control.Monad.IO.Class (liftIO)
+import Network.HTTP.Types.Status (ok200, badRequest400)
+import qualified Data.Text as T
+import qualified Data.Text.Encoding as TE
+import qualified Data.Text.Lazy as TL
+import Web.Scotty
+
+import qualified Common.Message as Message
+import qualified Common.Message.Key as Key
+import Common.Model (SignIn(..))
+
+import Conf (Conf)
+import qualified Conf
+import qualified Model.Query as Query
+import qualified Model.SignIn as SignIn
+import qualified Model.User as User
+import qualified SendMail
+import qualified Text.Email.Validate as Email
+import qualified View.Mail.SignIn as SignIn
+
+signIn :: Conf -> SignIn -> ActionM ()
+signIn conf (SignIn email) =
+  if Email.isValid (TE.encodeUtf8 email)
+    then do
+      maybeUser <- liftIO . Query.run $ User.get email
+      case maybeUser of
+        Just user -> do
+          token <- liftIO . Query.run $ SignIn.createSignInToken email
+          let url = T.concat [
+                      if Conf.https conf then "https://" else "http://",
+                      Conf.hostname conf,
+                      "?signInToken=",
+                      token
+                    ]
+          maybeSentMail <- liftIO . SendMail.sendMail $ SignIn.mail conf user url [email]
+          case maybeSentMail of
+            Right _ -> textKey ok200 Key.SignIn_EmailSent
+            Left _ -> textKey badRequest400 Key.SignIn_EmailSendFail
+        Nothing -> textKey badRequest400 Key.Secure_Unauthorized
+    else textKey badRequest400 Key.SignIn_EmailInvalid
+  where textKey st key = status st >> (text . TL.fromStrict $ Message.get key)
diff --git a/server/src/Cookie.hs b/server/src/Cookie.hs
new file mode 100644
index 0000000..96d45da
--- /dev/null
+++ b/server/src/Cookie.hs
@@ -0,0 +1,56 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Cookie
+  ( makeSimpleCookie
+  , setCookie
+  , setSimpleCookie
+  , getCookie
+  , getCookies
+  , deleteCookie
+  ) where
+
+import Control.Monad ( liftM )
+
+import qualified Data.Text as TS
+import qualified Data.Text.Encoding as TS
+import qualified Data.Text.Lazy.Encoding as TL
+
+import Conf (Conf)
+import qualified Conf
+
+import qualified Data.Map as Map
+
+import qualified Data.ByteString.Lazy as BSL
+
+import Data.Time.Clock.POSIX ( posixSecondsToUTCTime )
+
+import Blaze.ByteString.Builder ( toLazyByteString )
+
+import Web.Scotty.Trans
+import Web.Cookie
+
+makeSimpleCookie :: Conf -> TS.Text -> TS.Text -> SetCookie
+makeSimpleCookie conf name value =
+  def
+    { setCookieName  = TS.encodeUtf8 name
+    , setCookieValue = TS.encodeUtf8 value
+    , setCookiePath = Just $ TS.encodeUtf8 "/"
+    , setCookieSecure = Conf.https conf
+    }
+
+setCookie :: (Monad m) => SetCookie -> ActionT e m ()
+setCookie name = addHeader "Set-Cookie" (TL.decodeUtf8 . toLazyByteString $ renderSetCookie name)
+
+setSimpleCookie :: (Monad m) => Conf -> TS.Text -> TS.Text -> ActionT e m ()
+setSimpleCookie conf name value = setCookie $ makeSimpleCookie conf name value
+
+getCookie :: (Monad m, ScottyError e) => TS.Text -> ActionT e m (Maybe TS.Text)
+getCookie name = liftM (Map.lookup name) getCookies
+
+getCookies :: (Monad m, ScottyError e) => ActionT e m (Map.Map TS.Text TS.Text)
+getCookies =
+  liftM (Map.fromList . maybe [] parse) $ header "Cookie"
+  where parse = parseCookiesText . BSL.toStrict . TL.encodeUtf8
+
+deleteCookie :: (Monad m) => Conf -> TS.Text -> ActionT e m ()
+deleteCookie conf name = setCookie $ (makeSimpleCookie conf name "") { setCookieExpires = Just $ posixSecondsToUTCTime 0 }
diff --git a/server/src/Design/Color.hs b/server/src/Design/Color.hs
new file mode 100644
index 0000000..06c468e
--- /dev/null
+++ b/server/src/Design/Color.hs
@@ -0,0 +1,35 @@
+module Design.Color where
+
+import qualified Clay.Color as C
+
+-- http://chir.ag/projects/name-that-color/#969696
+
+white :: C.Color
+white = C.white
+
+black :: C.Color
+black = C.black
+
+chestnutRose :: C.Color
+chestnutRose = C.rgb 207 92 86
+
+unknown :: C.Color
+unknown = C.rgb 86 92 207
+
+mossGreen :: C.Color
+mossGreen = C.rgb 159 210 165
+
+gothic :: C.Color
+gothic = C.rgb 108 162 164
+
+negroni :: C.Color
+negroni = C.rgb 255 223 196
+
+wildSand :: C.Color
+wildSand = C.rgb 245 245 245
+
+silver :: C.Color
+silver = C.rgb 200 200 200
+
+dustyGray :: C.Color
+dustyGray = C.rgb 150 150 150
diff --git a/server/src/Design/Constants.hs b/server/src/Design/Constants.hs
new file mode 100644
index 0000000..4e2b8cc
--- /dev/null
+++ b/server/src/Design/Constants.hs
@@ -0,0 +1,27 @@
+module Design.Constants where
+
+import Clay
+
+iconFontSize :: Size LengthUnit
+iconFontSize = px 32
+
+radius :: Size LengthUnit
+radius = px 3
+
+blockPadding :: Size LengthUnit
+blockPadding = px 15
+
+blockPercentWidth :: Double
+blockPercentWidth = 90
+
+blockPercentMargin :: Double
+blockPercentMargin = (100 - blockPercentWidth) / 2
+
+inputHeight :: Double
+inputHeight = 40
+
+focusLighten :: Color -> Color
+focusLighten baseColor = baseColor +. 20
+
+focusDarken :: Color -> Color
+focusDarken baseColor = baseColor -. 20
diff --git a/server/src/Design/Dialog.hs b/server/src/Design/Dialog.hs
new file mode 100644
index 0000000..4678633
--- /dev/null
+++ b/server/src/Design/Dialog.hs
@@ -0,0 +1,24 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.Dialog
+  ( design
+  ) where
+
+import Data.Monoid ((<>))
+
+import Clay
+
+design :: Css
+design = do
+
+  ".content" ? do
+    minWidth (px 270)
+
+    ".paymentDialog" & do
+      ".radioGroup" ? ".title" ? display none
+      ".selectInput" ? do
+        select ? width (pct 100)
+        marginBottom (em 1)
+
+  ".deletePaymentDialog" <> ".deleteIncomeDialog" ? do
+    h1 ? marginBottom (em 1.5)
diff --git a/server/src/Design/Errors.hs b/server/src/Design/Errors.hs
new file mode 100644
index 0000000..57aaeee
--- /dev/null
+++ b/server/src/Design/Errors.hs
@@ -0,0 +1,55 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.Errors
+  ( design
+  ) where
+
+import Clay
+
+import Design.Color as Color
+
+design :: Css
+design = do
+  position fixed
+  top (px 20)
+  left (pct 50)
+  "transform" -: "translateX(-50%)"
+  margin (px 0) (px 0) (px 0) (px 0)
+  disapearKeyframes
+
+  ".error" ? do
+    disapearAnimation
+    let errorColor = Color.chestnutRose -. 15
+    color errorColor
+    border solid (px 2) errorColor
+    backgroundColor Color.white
+    borderRadius (px 5) (px 5) (px 5) (px 5)
+    padding (px 5) (px 5) (px 5) (px 5)
+
+    before & display none
+
+disapearAnimation :: Css
+disapearAnimation = do
+  animationName "disapear"
+  animationDelay (sec 5)
+  animationDuration (sec 1)
+  animationFillMode forwards
+
+disapearKeyframes :: Css
+disapearKeyframes = keyframes
+  "disapear"
+  [ ( 10
+    , do
+        opacity 0
+        height (px 40)
+        lineHeight (px 40)
+        marginBottom (px 10)
+    )
+  , ( 100
+    , do
+        opacity 0
+        height (px 0)
+        lineHeight (px 0)
+        marginBottom (px 0)
+    )
+  ]
diff --git a/server/src/Design/Form.hs b/server/src/Design/Form.hs
new file mode 100644
index 0000000..ebb8ac8
--- /dev/null
+++ b/server/src/Design/Form.hs
@@ -0,0 +1,130 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.Form
+  ( design
+  ) where
+
+import Data.Monoid ((<>))
+
+import Clay
+
+import Design.Color as Color
+
+design :: Css
+design = do
+
+  let inputHeight = 30
+  let inputTop = 22
+  let inputPaddingBottom = 3
+  let inputZIndex = 1
+
+  label ? do
+    cursor pointer
+    color Color.silver
+
+  ".textInput" ? do
+    position relative
+    marginBottom (em 1.5)
+    paddingTop (px inputTop)
+    marginTop (px (-10))
+
+    input ? do
+      width (pct 100)
+      position relative
+      zIndex inputZIndex
+      backgroundColor transparent
+      paddingBottom (px inputPaddingBottom)
+      borderStyle none
+      borderBottom solid (px 1) Color.dustyGray
+      marginBottom (px 5)
+      height (px inputHeight)
+      lineHeight (px inputHeight)
+      focus & do
+        borderWidth (px 2)
+        paddingBottom (px $ inputPaddingBottom - 1)
+
+    label ? do
+      lineHeight (px inputHeight)
+      position absolute
+      top (px inputTop)
+      left (px 0)
+      transition "all" (sec 0.2) easeIn (sec 0)
+
+    button ? do
+      position absolute
+      right (px 0)
+      top (px 27)
+      zIndex inputZIndex
+      hover & "svg path" ? do
+        "fill" -: "rgb(220, 220, 220)"
+
+    (input # ".filled" |+ label) <> (input # focus |+ label) ? do
+      top (px 0)
+      fontSize (pct 80)
+
+    ".error" & do
+      input ? do
+        borderBottomColor Color.chestnutRose
+
+      ".errorMessage" ? do
+        position absolute
+        color Color.chestnutRose
+        fontSize (pct 80)
+
+  ".colorInput" ? do
+    display flex
+    alignItems center
+    marginBottom (em 1.5)
+
+    input ? do
+      borderColor transparent
+      backgroundColor transparent
+
+  ".radioGroup" ? do
+    position relative
+    marginBottom (em 2)
+
+    ".title" ? do
+      color Color.silver
+      marginBottom (em 0.8)
+
+    ".radioInputs" ? do
+      display flex
+      "justify-content" -: "center"
+
+      ".radioInput:not(:last-child)::after" ? do
+        content (stringContent "/")
+        marginLeft (px 10)
+        marginRight (px 10)
+
+      input ? do
+        opacity 0
+        width (px 30)
+        margin (px 0) (px (-15)) (px 0) (px (-15))
+
+      "input:focus + label" ? do
+        textDecoration underline
+
+      "input:checked + label" ? do
+        color Color.chestnutRose
+        fontWeight bold
+
+  ".selectInput" ? do
+    label ? do
+      display block
+      marginBottom (px 10)
+      fontSize (pct 80)
+    select ? do
+      backgroundColor Color.white
+      border solid (px 1) Color.silver
+      sym borderRadius (px 3)
+      sym2 padding (px 5) (px 8)
+      option ? do
+        firstChild & display none
+        sym2 padding (px 5) (px 8)
+    ".error" & do
+      select ? borderColor Color.chestnutRose
+      ".errorMessage" ? do
+        color Color.chestnutRose
+        fontSize (pct 80)
+        marginTop (em 0.5)
diff --git a/server/src/Design/Global.hs b/server/src/Design/Global.hs
new file mode 100644
index 0000000..47ea4a9
--- /dev/null
+++ b/server/src/Design/Global.hs
@@ -0,0 +1,75 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.Global
+  ( globalDesign
+  ) where
+
+import Clay
+
+import Data.Text.Lazy (Text)
+
+import qualified Design.Views as Views
+import qualified Design.Form as Form
+import qualified Design.Errors as Errors
+import qualified Design.Dialog as Dialog
+import qualified Design.Tooltip as Tooltip
+
+import qualified Design.Color as Color
+import qualified Design.Helper as Helper
+import qualified Design.Constants as Constants
+import qualified Design.Media as Media
+
+globalDesign :: Text
+globalDesign = renderWith compact [] global
+
+global :: Css
+global = do
+  ".errors" ? Errors.design
+  ".dialog" ? Dialog.design
+  ".tooltip" ? Tooltip.design
+  Views.design
+  Form.design
+
+  body ? do
+    minWidth (px 320)
+    fontFamily ["Cantarell"] [sansSerif]
+    Media.tablet $ do
+      fontSize (px 15)
+      button ? fontSize (px 15)
+      input ? fontSize (px 15)
+    Media.mobile $ do
+      fontSize (px 14)
+      button ? fontSize (px 14)
+      input ? fontSize (px 14)
+
+  a ? cursor pointer
+
+  input ? fontSize inherit
+
+  h1 ? do
+    color Color.chestnutRose
+    marginBottom (em 1)
+    lineHeight (em 1.2)
+
+    Media.desktop $ fontSize (px 24)
+    Media.tablet $ fontSize (px 22)
+    Media.mobile $ fontSize (px 20)
+
+  ul ? do
+    "margin-bottom" -: "3vh"
+    "margin-left" -: "1vh"
+    li <? do
+      "margin-bottom" -: "2vh"
+      before & do
+        content (stringContent "• ")
+        color Color.chestnutRose
+        "margin-right" -: "0.3vw"
+      ul <? do
+        "margin-left" -: "3vh"
+        "margin-top" -: "2vh"
+
+  ".dialog" ? ".content" ? button ? do
+    ".confirm" & Helper.button Color.chestnutRose Color.white (px Constants.inputHeight) Constants.focusLighten
+    ".undo" & Helper.button Color.silver Color.white (px Constants.inputHeight) Constants.focusLighten
+
+  svg ? height (pct 100)
diff --git a/server/src/Design/Helper.hs b/server/src/Design/Helper.hs
new file mode 100644
index 0000000..41528ed
--- /dev/null
+++ b/server/src/Design/Helper.hs
@@ -0,0 +1,90 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.Helper
+  ( clearFix
+  , button
+  , waitable
+  , input
+  , centeredWithMargin
+  , verticalCentering
+  ) where
+
+import Prelude hiding (span)
+
+import Clay hiding (button, input)
+
+import Design.Constants
+import Design.Color as Color
+
+clearFix :: Css
+clearFix =
+  after & do
+    content (stringContent "")
+    display displayTable
+    clear both
+
+button :: Color -> Color -> Size a -> (Color -> Color) -> Css
+button backgroundCol textCol h focusOp = do
+  display flex
+  alignItems center
+  justifyContent center
+  backgroundColor backgroundCol
+  padding (px 0) (px 10) (px 0) (px 10)
+  color textCol
+  borderRadius radius radius radius radius
+  verticalAlign middle
+  cursor pointer
+  lineHeight h
+  height h
+  textAlign (alignSide sideCenter)
+  hover & backgroundColor (focusOp backgroundCol)
+  focus & backgroundColor (focusOp backgroundCol)
+  waitable
+
+waitable :: Css
+waitable = do
+  svg # ".loader" ? display none
+  ".waiting" & do
+    ".content" ? do
+      display flex
+      fontSize (px 0)
+      opacity 0
+    svg # ".loader" ? do
+      display block
+      rotateKeyframes
+      rotateAnimation
+
+input :: Double -> Css
+input h = do
+  height (px h)
+  padding (px 10) (px 10) (px 10) (px 10)
+  borderRadius radius radius radius radius
+  border solid (px 1) Color.dustyGray
+  focus & borderColor Color.silver
+  verticalAlign middle
+
+centeredWithMargin :: Css
+centeredWithMargin = do
+  width (pct blockPercentWidth)
+  marginLeft auto
+  marginRight auto
+
+verticalCentering :: Css
+verticalCentering = do
+  position absolute
+  top (pct 50)
+  "transform" -: "translateY(-50%)"
+
+rotateAnimation :: Css
+rotateAnimation = do
+  animationName "rotate"
+  animationDuration (sec 1)
+  animationTimingFunction easeOut
+  animationIterationCount infinite
+
+rotateKeyframes :: Css
+rotateKeyframes = keyframes
+  "rotate"
+  [ (0, "transform" -: "rotate(0deg)")
+  , (100, "transform" -: "rotate(360deg)")
+  ]
diff --git a/server/src/Design/Media.hs b/server/src/Design/Media.hs
new file mode 100644
index 0000000..77220ee
--- /dev/null
+++ b/server/src/Design/Media.hs
@@ -0,0 +1,36 @@
+module Design.Media
+  ( mobile
+  , mobileTablet
+  , tablet
+  , tabletDesktop
+  , desktop
+  ) where
+
+import Clay hiding (query)
+import qualified Clay
+import Clay.Stylesheet (Feature)
+import qualified Clay.Media as Media
+
+mobile :: Css -> Css
+mobile = query [Media.maxWidth mobileTabletLimit]
+
+mobileTablet :: Css -> Css
+mobileTablet = query [Media.maxWidth tabletDesktopLimit]
+
+tablet :: Css -> Css
+tablet = query [Media.minWidth mobileTabletLimit, Media.maxWidth tabletDesktopLimit]
+
+tabletDesktop :: Css -> Css
+tabletDesktop = query [Media.minWidth mobileTabletLimit]
+
+desktop :: Css -> Css
+desktop = query [Media.minWidth tabletDesktopLimit]
+
+query :: [Feature] -> Css -> Css
+query = Clay.query Media.screen
+
+mobileTabletLimit :: Size LengthUnit
+mobileTabletLimit = (px 520)
+
+tabletDesktopLimit :: Size LengthUnit
+tabletDesktopLimit = (px 950)
diff --git a/server/src/Design/Tooltip.hs b/server/src/Design/Tooltip.hs
new file mode 100644
index 0000000..1da8764
--- /dev/null
+++ b/server/src/Design/Tooltip.hs
@@ -0,0 +1,16 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.Tooltip
+  ( design
+  ) where
+
+import Clay
+
+import Design.Color as Color
+
+design :: Css
+design = do
+  backgroundColor Color.mossGreen
+  borderRadius (px 5) (px 5) (px 5) (px 5)
+  padding (px 5) (px 5) (px 5) (px 5)
+  color Color.white
diff --git a/server/src/Design/View/Header.hs b/server/src/Design/View/Header.hs
new file mode 100644
index 0000000..20627e6
--- /dev/null
+++ b/server/src/Design/View/Header.hs
@@ -0,0 +1,78 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.View.Header
+  ( design
+  ) where
+
+import Data.Monoid ((<>))
+
+import Clay
+
+import Design.Color as Color
+import qualified Design.Helper as Helper
+import qualified Design.Media as Media
+
+design :: Css
+design = do
+  let headerPadding = "padding" -: "0 20px"
+  display flex
+  "flex-wrap" -: "wrap"
+  lineHeightMedia
+  position relative
+  backgroundColor Color.chestnutRose
+  color Color.white
+  Media.desktop $ marginBottom (em 3)
+  Media.mobileTablet $ marginBottom (em 2)
+  Media.mobile $ marginBottom (em 1.5)
+
+  ".title" <> ".item" ? headerPadding
+
+  ".title" ? do
+    height (pct 100)
+    textAlign (alignSide sideLeft)
+
+    Media.mobile $ fontSize (px 22)
+    Media.mobileTablet $ width (pct 100)
+    Media.tabletDesktop $ do
+      display inlineBlock
+      fontSize (px 35)
+
+  ".item" ? do
+    display inlineBlock
+    transition "background-color" (ms 50) easeIn (sec 0)
+    ".current" & backgroundColor (Color.chestnutRose -. 20)
+    Media.mobile $ fontSize (px 13)
+
+  (".item" # hover) <> (".item" # focus) ? backgroundColor (Color.chestnutRose +. 10)
+  (".item.current" # hover) <> (".item.current" # focus) ? backgroundColor (Color.chestnutRose -. 10)
+
+  ".nameSignOut" ? do
+    display flex
+    heightMedia
+    position absolute
+    top (px 0)
+    right (px 0)
+
+    ".name" ? do
+      Media.mobile $ display none
+      Media.tabletDesktop $ headerPadding
+
+    ".signOut" ? do
+      Helper.waitable
+      heightMedia
+      svg ? do
+        Media.tabletDesktop $ width (px 30)
+        Media.mobile $ width (px 20)
+        "path" ? ("fill" -: "white")
+
+lineHeightMedia :: Css
+lineHeightMedia = do
+  Media.desktop $ lineHeight (px 80)
+  Media.tablet $ lineHeight (px 65)
+  Media.mobile $ lineHeight (px 50)
+
+heightMedia :: Css
+heightMedia = do
+  Media.desktop $ height (px 80)
+  Media.tablet $ height (px 65)
+  Media.mobile $ height (px 50)
diff --git a/server/src/Design/View/Payment.hs b/server/src/Design/View/Payment.hs
new file mode 100644
index 0000000..d3c7650
--- /dev/null
+++ b/server/src/Design/View/Payment.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.View.Payment
+  ( design
+  ) where
+
+import Clay
+
+import qualified Design.View.Payment.Header as Header
+import qualified Design.View.Payment.Table as Table
+import qualified Design.View.Payment.Pages as Pages
+
+design :: Css
+design = do
+  ".header" ? Header.design
+  ".table" ? Table.design
+  ".pages" ? Pages.design
diff --git a/server/src/Design/View/Payment/Header.hs b/server/src/Design/View/Payment/Header.hs
new file mode 100644
index 0000000..f02da8a
--- /dev/null
+++ b/server/src/Design/View/Payment/Header.hs
@@ -0,0 +1,84 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.View.Payment.Header
+  ( design
+  ) where
+
+import Data.Monoid ((<>))
+
+import Clay
+
+import Design.Constants
+
+import qualified Design.Helper as Helper
+import qualified Design.Color as Color
+import qualified Design.Constants as Constants
+import qualified Design.Media as Media
+
+design :: Css
+design = do
+  Media.desktop $ marginBottom (em 3)
+  Media.mobileTablet $ marginBottom (em 2)
+  marginLeft (pct blockPercentMargin)
+  marginRight (pct blockPercentMargin)
+
+  ".payerAndAdd" ? do
+    Media.tabletDesktop $ display flex
+    marginBottom (em 1)
+
+    ".exceedingPayers" ? do
+      backgroundColor Color.mossGreen
+      borderRadius (px 5) (px 5) (px 5) (px 5)
+      color Color.white
+      lineHeight (px Constants.inputHeight)
+      paddingLeft (px 10)
+      paddingRight (px 10)
+
+      Media.tabletDesktop $ do
+        "flex-grow" -: "1"
+        marginRight (px 15)
+
+      Media.mobile $ do
+        marginBottom (em 1)
+        textAlign (alignSide sideCenter)
+
+      ".exceedingPayer:not(:last-child)::after" ? content (stringContent ", ")
+
+      ".userName" ? marginRight (px 8)
+
+    ".addPayment" ? do
+      Helper.button Color.chestnutRose Color.white (px Constants.inputHeight) Constants.focusLighten
+      Media.mobile $ width (pct 100)
+
+  ".searchLine" ? do
+    marginBottom (em 1)
+    form ? do
+      Media.mobile $ textAlign (alignSide sideCenter)
+
+      ".textInput" ? do
+        display inlineBlock
+        marginBottom (px 0)
+
+        Media.tabletDesktop $ marginRight (px 30)
+        Media.mobile $ do
+          marginBottom (em 1)
+          width (pct 100)
+
+      ".radioGroup" ? do
+        display inlineBlock
+        marginBottom (px 0)
+        ".title" ? display none
+
+  ".infos" ? do
+    Media.tabletDesktop $ lineHeight (px Constants.inputHeight)
+    Media.mobile $ lineHeight (px 25)
+
+    ".total" <> ".partition" ? do
+      Media.mobileTablet $ display block
+      Media.mobile $ do
+        fontSize (pct 90)
+        textAlign (alignSide sideCenter)
+
+    ".partition" ? do
+      color Color.dustyGray
+      Media.desktop $ marginLeft (px 15)
diff --git a/server/src/Design/View/Payment/Pages.hs b/server/src/Design/View/Payment/Pages.hs
new file mode 100644
index 0000000..ade81a8
--- /dev/null
+++ b/server/src/Design/View/Payment/Pages.hs
@@ -0,0 +1,54 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.View.Payment.Pages
+  ( design
+  ) where
+
+import Clay
+
+import qualified Design.Color as Color
+import qualified Design.Helper as Helper
+import qualified Design.Constants as Constants
+import qualified Design.Media as Media
+
+design :: Css
+design = do
+  textAlign (alignSide sideCenter)
+  Helper.clearFix
+
+  Media.desktop $ do
+    padding (px 40) (px 30) (px 30) (px 30)
+
+  Media.tablet $ do
+    padding (px 30) (px 30) (px 30) (px 30)
+
+  Media.mobile $ do
+    padding (px 20) (px 0) (px 20) (px 0)
+    lineHeight (px 40)
+
+  ".page" ? do
+    display inlineBlock
+    fontWeight bold
+
+    Media.desktop $ do
+      Helper.button Color.white Color.dustyGray (px 50) Constants.focusDarken
+
+    Media.tabletDesktop $ do
+      border solid (px 2) Color.dustyGray
+      marginRight (px 10)
+
+    Media.tablet $ do
+      Helper.button Color.white Color.dustyGray (px 40) Constants.focusDarken
+      fontSize (px 15)
+
+    Media.mobile $ do
+      Helper.button Color.white Color.dustyGray (px 30) Constants.focusDarken
+      fontSize (px 12)
+      border solid (px 1) Color.dustyGray
+      marginRight (px 5)
+
+    ":not(.current)" & cursor pointer
+
+    ".current" & do
+      borderColor Color.chestnutRose
+      color Color.chestnutRose
diff --git a/server/src/Design/View/Payment/Table.hs b/server/src/Design/View/Payment/Table.hs
new file mode 100644
index 0000000..a866b40
--- /dev/null
+++ b/server/src/Design/View/Payment/Table.hs
@@ -0,0 +1,42 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.View.Payment.Table
+  ( design
+  ) where
+
+import Clay
+
+import qualified Design.Color as Color
+import qualified Design.Media as Media
+
+design :: Css
+design = do
+  ".cell" ? do
+    ".name" & do
+      Media.tabletDesktop $ width (pct 30)
+
+    ".cost" & do
+      Media.tabletDesktop $ width (pct 10)
+
+    ".user" & do
+      Media.tabletDesktop $ width (pct 15)
+
+    ".category" & do
+      Media.tabletDesktop $ width (pct 10)
+
+    ".date" & do
+      Media.tabletDesktop $ width (pct 15)
+      Media.desktop $ do
+        ".shortDate" ? display none
+        ".longDate" ? display inline
+      Media.tablet $ do
+        ".shortDate" ? display inline
+        ".longDate" ? display none
+      Media.mobile $ do
+        ".shortDate" ? display none
+        ".longDate" ? display inline
+        marginBottom (em 0.5)
+
+    ".button" & svg ? do
+      "path" ? ("fill" -: (plain . unValue . value $ Color.chestnutRose))
+      width (px 18)
diff --git a/server/src/Design/View/SignIn.hs b/server/src/Design/View/SignIn.hs
new file mode 100644
index 0000000..214e663
--- /dev/null
+++ b/server/src/Design/View/SignIn.hs
@@ -0,0 +1,42 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.View.SignIn
+  ( design
+  ) where
+
+import Clay
+import Data.Monoid ((<>))
+
+import qualified Design.Color as Color
+import qualified Design.Helper as Helper
+import qualified Design.Constants as Constants
+
+design :: Css
+design = do
+  let inputHeight = 50
+  width (px 500)
+  marginTop (px 100)
+  marginLeft auto
+  marginRight auto
+
+  input ? do
+    Helper.input inputHeight
+    display block
+    width (pct 100)
+    marginBottom (px 10)
+
+  button ? do
+    Helper.button Color.gothic Color.white (px inputHeight) Constants.focusLighten
+    display flex
+    alignItems center
+    justifyContent center
+    width (pct 100)
+    fontSize (em 1.2)
+    svg ? "path" ? ("fill" -: "white")
+
+  ".success" <> ".error" ? do
+    marginTop (px 40)
+    textAlign (alignSide sideCenter)
+
+  ".success" ? color Color.mossGreen
+  ".error" ? color Color.chestnutRose
diff --git a/server/src/Design/View/Stat.hs b/server/src/Design/View/Stat.hs
new file mode 100644
index 0000000..0a5b258
--- /dev/null
+++ b/server/src/Design/View/Stat.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.View.Stat
+  ( design
+  ) where
+
+import Clay
+
+design :: Css
+design = do
+  h1 ? paddingBottom (px 0)
+
+  ".exceedingPayers" ? ".userName" ? marginRight (px 5)
+
+  ".mean" ? marginBottom (em 1.5)
diff --git a/server/src/Design/View/Table.hs b/server/src/Design/View/Table.hs
new file mode 100644
index 0000000..95abf90
--- /dev/null
+++ b/server/src/Design/View/Table.hs
@@ -0,0 +1,84 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.View.Table
+  ( design
+  ) where
+
+import Data.Monoid ((<>))
+
+import Clay
+
+import Design.Color as Color
+import qualified Design.Media as Media
+
+design :: Css
+design = do
+  ".emptyTableMsg" ? do
+    margin (em 2) (em 2) (em 2) (em 2)
+    textAlign (alignSide sideCenter)
+
+  ".lines" ? do
+    Media.tabletDesktop $ display displayTable
+    width (pct 100)
+    textAlign (alignSide (sideCenter))
+
+    ".header" <> ".row" ? do
+      Media.tabletDesktop $ display tableRow
+
+    ".header" ? do
+      Media.desktop $ do
+        fontSize (px 18)
+        height (px 70)
+
+      Media.tabletDesktop $ do
+        backgroundColor Color.gothic
+        color Color.white
+
+      Media.tablet $ do
+        fontSize (px 16)
+        height (px 60)
+
+      Media.mobile $ do
+        display none
+
+    ".row" ? do
+      nthChild "even" & backgroundColor Color.wildSand
+
+      Media.desktop $ do
+        fontSize (px 18)
+        height (px 60)
+
+      Media.tablet $ do
+        height (px 50)
+
+      Media.mobile $ do
+        lineHeight (px 25)
+        paddingTop (px 10)
+        paddingBottom (px 10)
+
+    ".cell" ? do
+      Media.tabletDesktop $ display tableCell
+      position relative
+      verticalAlign middle
+
+      firstChild & do
+        Media.mobile $ do
+          fontSize (px 20)
+          lineHeight (px 30)
+          color Color.gothic
+
+      ".refund" & color Color.mossGreen
+
+      ".cell.button" & do
+        position relative
+        textAlign (alignSide sideCenter)
+        button ? do
+          padding (px 10) (px 10) (px 10) (px 10)
+          hover & "svg path" ? do
+            "fill" -: "rgb(237, 122, 116)"
+
+        Media.tabletDesktop $ width (pct 3)
+
+        Media.mobile $ do
+          display inlineBlock
+          button ? display flex
diff --git a/server/src/Design/Views.hs b/server/src/Design/Views.hs
new file mode 100644
index 0000000..bc6ac83
--- /dev/null
+++ b/server/src/Design/Views.hs
@@ -0,0 +1,49 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Design.Views
+  ( design
+  ) where
+
+import Clay
+
+import qualified Design.View.Header as Header
+import qualified Design.View.Payment as Payment
+import qualified Design.View.SignIn as SignIn
+import qualified Design.View.Stat as Stat
+import qualified Design.View.Table as Table
+
+import qualified Design.Helper as Helper
+import qualified Design.Constants as Constants
+import qualified Design.Color as Color
+import qualified Design.Media as Media
+
+design :: Css
+design = do
+  header ? Header.design
+  ".payment" ? Payment.design
+  ".signIn" ? SignIn.design
+  ".stat" ? Stat.design
+  Table.design
+
+  ".withMargin" ? do
+    "margin" -: "0 2vw"
+
+  ".titleButton" ? do
+    h1 ? do
+      Media.tabletDesktop $ float floatLeft
+
+    button ? do
+      Helper.button Color.chestnutRose Color.white (px Constants.inputHeight) Constants.focusLighten
+      Media.tabletDesktop $ do
+        float floatRight
+        position relative
+        top (px (-8))
+      Media.mobile $ do
+        width (pct 100)
+        marginBottom (px 20)
+
+  ".tag" ? do
+    sym borderRadius (px 4)
+    sym2 padding (px 2) (px 5)
+    boxShadow (px 2) (px 2) (px 5) (rgba 0 0 0 0.3)
+    color Color.white
diff --git a/server/src/Job/Daemon.hs b/server/src/Job/Daemon.hs
new file mode 100644
index 0000000..0bc6f6e
--- /dev/null
+++ b/server/src/Job/Daemon.hs
@@ -0,0 +1,36 @@
+module Job.Daemon
+  ( runDaemons
+  ) where
+
+import Control.Concurrent (threadDelay, forkIO, ThreadId)
+import Control.Monad (forever)
+import Data.Time.Clock (UTCTime)
+
+import Conf (Conf)
+import Job.Frequency (Frequency(..), microSeconds)
+import Job.Kind (Kind(..))
+import Job.Model (getLastExecution, actualizeLastCheck, actualizeLastExecution)
+import Job.MonthlyPayment (monthlyPayment)
+import Job.WeeklyReport (weeklyReport)
+import qualified Model.Query as Query
+import Utils.Time (belongToCurrentMonth, belongToCurrentWeek)
+
+runDaemons :: Conf -> IO ()
+runDaemons conf = do
+  _ <- runDaemon MonthlyPayment EveryHour (fmap not . belongToCurrentMonth) monthlyPayment
+  _ <- runDaemon WeeklyReport EveryHour (fmap not . belongToCurrentWeek) (weeklyReport conf)
+  return ()
+
+runDaemon :: Kind -> Frequency -> (UTCTime -> IO Bool) -> (Maybe UTCTime -> IO UTCTime) -> IO ThreadId
+runDaemon kind frequency isLastExecutionTooOld runJob =
+  forkIO . forever $ do
+    mbLastExecution <- Query.run $ do
+      actualizeLastCheck kind
+      getLastExecution kind
+    hasToRun <- case mbLastExecution of
+      Just lastExecution -> isLastExecutionTooOld lastExecution
+      Nothing -> return True
+    if hasToRun
+      then runJob mbLastExecution >>= (Query.run . actualizeLastExecution kind)
+      else return ()
+    threadDelay . microSeconds $ frequency
diff --git a/server/src/Job/Frequency.hs b/server/src/Job/Frequency.hs
new file mode 100644
index 0000000..263f6e6
--- /dev/null
+++ b/server/src/Job/Frequency.hs
@@ -0,0 +1,13 @@
+module Job.Frequency
+  ( Frequency(..)
+  , microSeconds
+  ) where
+
+data Frequency =
+  EveryHour
+  | EveryDay
+  deriving (Eq, Read, Show)
+
+microSeconds :: Frequency -> Int
+microSeconds EveryHour = 1000000 * 60 * 60
+microSeconds EveryDay = (microSeconds EveryHour) * 24
diff --git a/server/src/Job/Kind.hs b/server/src/Job/Kind.hs
new file mode 100644
index 0000000..af5d4f8
--- /dev/null
+++ b/server/src/Job/Kind.hs
@@ -0,0 +1,22 @@
+module Job.Kind
+  ( Kind(..)
+  ) where
+
+import Database.SQLite.Simple (SQLData(SQLText))
+import Database.SQLite.Simple.FromField (fieldData, FromField(fromField))
+import Database.SQLite.Simple.Ok (Ok(Ok, Errors))
+import Database.SQLite.Simple.ToField (ToField(toField))
+import qualified Data.Text as T
+
+data Kind =
+  MonthlyPayment
+  | WeeklyReport
+  deriving (Eq, Show, Read)
+
+instance FromField Kind where
+  fromField field = case fieldData field of
+    SQLText text -> Ok (read (T.unpack text) :: Kind)
+    _ -> Errors [error "SQLText field required for job kind"]
+
+instance ToField Kind where
+  toField kind = SQLText . T.pack . show $ kind
diff --git a/server/src/Job/Model.hs b/server/src/Job/Model.hs
new file mode 100644
index 0000000..e1a3c77
--- /dev/null
+++ b/server/src/Job/Model.hs
@@ -0,0 +1,47 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Job.Model
+  ( Job(..)
+  , getLastExecution
+  , actualizeLastExecution
+  , actualizeLastCheck
+  ) where
+
+import Data.Maybe (isJust)
+import Data.Time.Clock (UTCTime, getCurrentTime)
+import Database.SQLite.Simple (Only(Only))
+import qualified Database.SQLite.Simple as SQLite
+import Prelude hiding (id)
+
+import Job.Kind
+import Model.Query (Query(Query))
+
+data Job = Job
+  { id :: String
+  , kind :: Kind
+  , lastExecution :: Maybe UTCTime
+  , lastCheck :: Maybe UTCTime
+  } deriving (Show)
+
+getLastExecution :: Kind -> Query (Maybe UTCTime)
+getLastExecution jobKind =
+  Query (\conn -> do
+    [Only time] <- SQLite.query conn "SELECT last_execution FROM job WHERE kind = ?" (Only jobKind) :: IO [Only (Maybe UTCTime)]
+    return time
+  )
+
+actualizeLastExecution :: Kind -> UTCTime -> Query ()
+actualizeLastExecution jobKind time =
+  Query (\conn -> do
+    [Only result] <- SQLite.query conn "SELECT 1 FROM job WHERE kind = ?" (Only jobKind) :: IO [Only (Maybe Int)]
+    if isJust result
+      then SQLite.execute conn "UPDATE job SET last_execution = ? WHERE kind = ?" (time, jobKind)
+      else SQLite.execute conn "INSERT INTO job (kind, last_execution, last_check) VALUES (?, ?, ?)" (jobKind, time, time)
+  )
+
+actualizeLastCheck :: Kind -> Query ()
+actualizeLastCheck jobKind =
+  Query (\conn -> do
+    now <- getCurrentTime
+    SQLite.execute conn "UPDATE job SET kind = ? WHERE last_check = ?" (jobKind, now)
+  )
diff --git a/server/src/Job/MonthlyPayment.hs b/server/src/Job/MonthlyPayment.hs
new file mode 100644
index 0000000..ba24cca
--- /dev/null
+++ b/server/src/Job/MonthlyPayment.hs
@@ -0,0 +1,26 @@
+module Job.MonthlyPayment
+  ( monthlyPayment
+  ) where
+
+import Data.Time.Clock (UTCTime, getCurrentTime)
+
+import Common.Model (Frequency(..), Payment(..))
+
+import qualified Model.Payment as Payment
+import Utils.Time (timeToDay)
+import qualified Model.Query as Query
+
+monthlyPayment :: Maybe UTCTime -> IO UTCTime
+monthlyPayment _ = do
+  monthlyPayments <- Query.run Payment.listMonthly
+  now <- getCurrentTime
+  actualDay <- timeToDay now
+  let punctualPayments = map
+        (\p -> p
+          { _payment_frequency = Punctual
+          , _payment_date = actualDay
+          , _payment_createdAt = now
+          })
+        monthlyPayments
+  _ <- Query.run (Payment.createMany punctualPayments)
+  return now
diff --git a/server/src/Job/WeeklyReport.hs b/server/src/Job/WeeklyReport.hs
new file mode 100644
index 0000000..5737c75
--- /dev/null
+++ b/server/src/Job/WeeklyReport.hs
@@ -0,0 +1,28 @@
+module Job.WeeklyReport
+  ( weeklyReport
+  ) where
+
+import Data.Time.Clock (UTCTime, getCurrentTime)
+
+import Conf (Conf)
+import qualified Model.Income as Income
+import qualified Model.Payment as Payment
+import qualified Model.Query as Query
+import qualified Model.User as User
+import qualified SendMail
+import qualified View.Mail.WeeklyReport as WeeklyReport
+
+weeklyReport :: Conf -> Maybe UTCTime -> IO UTCTime
+weeklyReport conf mbLastExecution = do
+  now <- getCurrentTime
+  case mbLastExecution of
+    Nothing -> return ()
+    Just lastExecution -> do
+      (payments, incomes, users) <- Query.run $
+        (,,) <$>
+          Payment.modifiedDuring lastExecution now <*>
+          Income.modifiedDuring lastExecution now <*>
+          User.list
+      _ <- SendMail.sendMail (WeeklyReport.mail conf users payments incomes lastExecution now)
+      return ()
+  return now
diff --git a/server/src/Json.hs b/server/src/Json.hs
new file mode 100644
index 0000000..cc6327a
--- /dev/null
+++ b/server/src/Json.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE FlexibleContexts           #-}
+
+module Json
+  ( jsonObject
+  , jsonId
+  ) where
+
+import Data.Int (Int64)
+import Data.Text (Text)
+import qualified Data.Aeson.Types as Json
+import qualified Data.HashMap.Strict as M
+import Web.Scotty
+
+jsonObject :: [(Text, Json.Value)] -> ActionM ()
+jsonObject = json . Json.Object . M.fromList
+
+jsonId :: Int64 -> ActionM ()
+jsonId key = json . Json.Object . M.fromList $ [("id", Json.Number . fromIntegral $ key)]
diff --git a/server/src/LoginSession.hs b/server/src/LoginSession.hs
new file mode 100644
index 0000000..6f6d620
--- /dev/null
+++ b/server/src/LoginSession.hs
@@ -0,0 +1,53 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module LoginSession
+  ( put
+  , get
+  , delete
+  ) where
+
+import Web.Scotty (ActionM)
+import Cookie (setSimpleCookie, getCookie, deleteCookie)
+import qualified Web.ClientSession as CS
+
+import Control.Monad.IO.Class (liftIO)
+
+import Data.Text (Text)
+import qualified Data.Text.Encoding as TE
+
+import Conf (Conf)
+
+sessionName :: Text
+sessionName = "SESSION"
+
+sessionKeyFile :: FilePath
+sessionKeyFile = "sessionKey"
+
+put :: Conf -> Text -> ActionM ()
+put conf value = do
+  encrypted <- liftIO $ encrypt value
+  setSimpleCookie conf sessionName encrypted
+
+encrypt :: Text -> IO Text
+encrypt value = do
+  iv <- CS.randomIV
+  key <- CS.getKey sessionKeyFile
+  return . TE.decodeUtf8 $ CS.encrypt key iv (TE.encodeUtf8 value)
+
+get :: ActionM (Maybe Text)
+get = do
+  maybeEncrypted <- getCookie sessionName
+  case maybeEncrypted of
+    Just encrypted ->
+      liftIO $ decrypt encrypted
+    Nothing ->
+      return Nothing
+
+decrypt :: Text -> IO (Maybe Text)
+decrypt encrypted = do
+  key <- CS.getKey sessionKeyFile
+  let decrypted = TE.decodeUtf8 <$> CS.decrypt key (TE.encodeUtf8 encrypted)
+  return decrypted
+
+delete :: Conf -> ActionM ()
+delete conf = deleteCookie conf sessionName
diff --git a/server/src/Main.hs b/server/src/Main.hs
new file mode 100644
index 0000000..db73474
--- /dev/null
+++ b/server/src/Main.hs
@@ -0,0 +1,79 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+import Control.Applicative (liftA3)
+import Control.Monad.IO.Class (liftIO)
+
+import Network.Wai.Middleware.Static
+import qualified Data.Text.Lazy as LT
+import Web.Scotty
+
+import qualified Conf
+import qualified Controller.Category as Category
+import qualified Controller.Income as Income
+import qualified Controller.Index as Index
+import qualified Controller.Payment as Payment
+import qualified Controller.SignIn as SignIn
+import Job.Daemon (runDaemons)
+import Model.Payer (getOrderedExceedingPayers)
+import qualified Data.Time as Time
+import qualified Model.User as UserM
+import qualified Model.Income as IncomeM
+import qualified Model.Payment as PaymentM
+import qualified Model.Query as Query
+
+main :: IO ()
+main = do
+  conf <- Conf.get "application.conf"
+  _ <- runDaemons conf
+  scotty (Conf.port conf) $ do
+    middleware . staticPolicy $ noDots >-> addBase "public"
+
+    get "/exceedingPayer" $ do
+      time <- liftIO Time.getCurrentTime
+      (users, incomes, payments) <- liftIO . Query.run $
+        liftA3 (,,) UserM.list IncomeM.list PaymentM.list
+      let exceedingPayers = getOrderedExceedingPayers time users incomes payments
+      text . LT.pack . show $ exceedingPayers
+
+    get "/" $ do
+      signInToken <- mbParam "signInToken"
+      Index.get conf signInToken
+
+    post "/signIn" $ do
+      jsonData >>= SignIn.signIn conf
+
+    post "/signOut" $
+      Index.signOut conf
+
+    post "/payment" $
+      jsonData >>= Payment.create
+
+    put "/payment" $
+      jsonData >>= Payment.editOwn
+
+    delete "/payment" $ do
+      paymentId <- param "id"
+      Payment.deleteOwn paymentId
+
+    post "/income" $
+      jsonData >>= Income.create
+
+    put "/income" $
+      jsonData >>= Income.editOwn
+
+    delete "/income" $ do
+      incomeId <- param "id"
+      Income.deleteOwn incomeId
+
+    post "/category" $
+      jsonData >>= Category.create
+
+    put "/category" $
+      jsonData >>= Category.edit
+
+    delete "/category" $ do
+      categoryId <- param "id"
+      Category.delete categoryId
+
+mbParam :: Parsable a => LT.Text -> ActionM (Maybe a)
+mbParam key = (Just <$> param key) `rescue` (const . return $ Nothing)
diff --git a/server/src/MimeMail.hs b/server/src/MimeMail.hs
new file mode 100644
index 0000000..0faaf98
--- /dev/null
+++ b/server/src/MimeMail.hs
@@ -0,0 +1,672 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module MimeMail
+    ( -- * Datatypes
+      Boundary (..)
+    , Mail (..)
+    , emptyMail
+    , Address (..)
+    , Alternatives
+    , Part (..)
+    , Encoding (..)
+    , Headers
+      -- * Render a message
+    , renderMail
+    , renderMail'
+      -- * Sending messages
+    , sendmail
+    , sendmailCustom
+    , sendmailCustomCaptureOutput
+    , renderSendMail
+    , renderSendMailCustom
+      -- * High-level 'Mail' creation
+    , simpleMail
+    , simpleMail'
+    , simpleMailInMemory
+      -- * Utilities
+    , addPart
+    , addAttachment
+    , addAttachmentCid
+    , addAttachments
+    , addAttachmentBS
+    , addAttachmentBSCid
+    , addAttachmentsBS
+    , renderAddress
+    , htmlPart
+    , plainPart
+    , randomString
+    , quotedPrintable
+    ) where
+
+import qualified Data.ByteString.Lazy as L
+import Blaze.ByteString.Builder.Char.Utf8
+import Blaze.ByteString.Builder
+import Control.Concurrent (forkIO, putMVar, takeMVar, newEmptyMVar)
+import Data.Monoid
+import System.Random
+import Control.Arrow
+import System.Process
+import System.IO
+import System.Exit
+import System.FilePath (takeFileName)
+import qualified Data.ByteString.Base64 as Base64
+import Control.Monad ((<=<), foldM, void)
+import Control.Exception (throwIO, ErrorCall (ErrorCall))
+import Data.List (intersperse)
+import qualified Data.Text.Lazy as LT
+import qualified Data.Text.Lazy.Encoding as LT
+import Data.ByteString.Char8 ()
+import Data.Bits ((.&.), shiftR)
+import Data.Char (isAscii, isControl)
+import Data.Word (Word8)
+import qualified Data.ByteString as S
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified Data.Text.Encoding as TE
+
+-- | Generates a random sequence of alphanumerics of the given length.
+randomString :: RandomGen d => Int -> d -> (String, d)
+randomString len =
+    first (map toChar) . sequence' (replicate len (randomR (0, 61)))
+  where
+    sequence' [] g = ([], g)
+    sequence' (f:fs) g =
+        let (f', g') = f g
+            (fs', g'') = sequence' fs g'
+         in (f' : fs', g'')
+    toChar i
+        | i < 26 = toEnum $ i + fromEnum 'A'
+        | i < 52 = toEnum $ i + fromEnum 'a' - 26
+        | otherwise = toEnum $ i + fromEnum '0' - 52
+
+-- | MIME boundary between parts of a message.
+newtype Boundary = Boundary { unBoundary :: Text }
+  deriving (Eq, Show)
+instance Random Boundary where
+    randomR = const random
+    random = first (Boundary . T.pack) . randomString 10
+
+-- | An entire mail message.
+data Mail = Mail
+    { mailFrom :: Address
+    , mailTo   :: [Address]
+    , mailCc   :: [Address]
+    , mailBcc  :: [Address]
+    -- | Other headers, excluding from, to, cc and bcc.
+    , mailHeaders :: Headers
+    -- | A list of different sets of alternatives. As a concrete example:
+    --
+    -- > mailParts = [ [textVersion, htmlVersion], [attachment1], [attachment1]]
+    --
+    -- Make sure when specifying alternatives to place the most preferred
+    -- version last.
+    , mailParts :: [Alternatives]
+    }
+  deriving Show
+
+-- | A mail message with the provided 'from' address and no other
+-- fields filled in.
+emptyMail :: Address -> Mail
+emptyMail from = Mail
+    { mailFrom    = from
+    , mailTo      = []
+    , mailCc      = []
+    , mailBcc     = []
+    , mailHeaders = []
+    , mailParts   = []
+    }
+
+data Address = Address
+    { addressName  :: Maybe Text
+    , addressEmail :: Text
+    }
+  deriving (Eq, Show)
+
+-- | How to encode a single part. You should use 'Base64' for binary data.
+data Encoding = None | Base64 | QuotedPrintableText | QuotedPrintableBinary
+  deriving (Eq, Show)
+
+-- | Multiple alternative representations of the same data. For example, you
+-- could provide a plain-text and HTML version of a message.
+type Alternatives = [Part]
+
+-- | A single part of a multipart message.
+data Part = Part
+    { partType :: Text -- ^ content type
+    , partEncoding :: Encoding
+    -- | The filename for this part, if it is to be sent with an attachemnt
+    -- disposition.
+    , partFilename :: Maybe Text
+    , partHeaders :: Headers
+    , partContent :: L.ByteString
+    }
+  deriving (Eq, Show)
+
+type Headers = [(S.ByteString, Text)]
+type Pair = (Headers, Builder)
+
+partToPair :: Part -> Pair
+partToPair (Part contentType encoding disposition headers content) =
+    (headers', builder)
+  where
+    headers' =
+        ((:) ("Content-Type", contentType))
+      $ (case encoding of
+            None -> id
+            Base64 -> (:) ("Content-Transfer-Encoding", "base64")
+            QuotedPrintableText ->
+                (:) ("Content-Transfer-Encoding", "quoted-printable")
+            QuotedPrintableBinary ->
+                (:) ("Content-Transfer-Encoding", "quoted-printable"))
+      $ (case disposition of
+            Nothing -> id
+            Just fn ->
+                (:) ("Content-Disposition", "attachment; filename="
+                                            `T.append` fn))
+      $ headers
+    builder =
+        case encoding of
+            None -> fromWriteList writeByteString $ L.toChunks content
+            Base64 -> base64 content
+            QuotedPrintableText -> quotedPrintable True content
+            QuotedPrintableBinary -> quotedPrintable False content
+
+showPairs :: RandomGen g
+          => Text -- ^ multipart type, eg mixed, alternative
+          -> [Pair]
+          -> g
+          -> (Pair, g)
+showPairs _ [] _ = error "renderParts called with null parts"
+showPairs _ [pair] gen = (pair, gen)
+showPairs mtype parts gen =
+    ((headers, builder), gen')
+  where
+    (Boundary b, gen') = random gen
+    headers =
+        [ ("Content-Type", T.concat
+            [ "multipart/"
+            , mtype
+            , "; boundary=\""
+            , b
+            , "\""
+            ])
+        ]
+    builder = mconcat
+        [ mconcat $ intersperse (fromByteString "\n")
+                  $ map (showBoundPart $ Boundary b) parts
+        , showBoundEnd $ Boundary b
+        ]
+
+-- | Render a 'Mail' with a given 'RandomGen' for producing boundaries.
+renderMail :: RandomGen g => g -> Mail -> (L.ByteString, g)
+renderMail g0 (Mail from to cc bcc headers parts) =
+    (toLazyByteString builder, g'')
+  where
+    addressHeaders = map showAddressHeader [("From", [from]), ("To", to), ("Cc", cc), ("Bcc", bcc)]
+    pairs = map (map partToPair) parts
+    (pairs', g') = helper g0 $ map (showPairs "alternative") pairs
+    helper :: g -> [g -> (x, g)] -> ([x], g)
+    helper g [] = ([], g)
+    helper g (x:xs) =
+        let (b, g_) = x g
+            (bs, g__) = helper g_ xs
+         in (b : bs, g__)
+    ((finalHeaders, finalBuilder), g'') = showPairs "mixed" pairs' g'
+    builder = mconcat
+        [ mconcat addressHeaders
+        , mconcat $ map showHeader headers
+        , showHeader ("MIME-Version", "1.0")
+        , mconcat $ map showHeader finalHeaders
+        , fromByteString "\n"
+        , finalBuilder
+        ]
+
+-- | Format an E-Mail address according to the name-addr form (see: RFC5322
+-- § 3.4 "Address specification", i.e: [display-name] '<'addr-spec'>')
+-- This can be handy for adding custom headers that require such format.
+--
+-- @since 0.4.11
+renderAddress :: Address -> Text
+renderAddress address =
+    TE.decodeUtf8 $ toByteString $ showAddress address
+
+-- Only accept characters between 33 and 126, excluding colons. [RFC2822](https://tools.ietf.org/html/rfc2822#section-2.2)
+sanitizeFieldName :: S.ByteString -> S.ByteString
+sanitizeFieldName = S.filter (\w -> w >= 33 && w <= 126 && w /= 58)
+
+showHeader :: (S.ByteString, Text) -> Builder
+showHeader (k, v) = mconcat
+    [ fromByteString (sanitizeFieldName k)
+    , fromByteString ": "
+    , encodeIfNeeded (sanitizeHeader v)
+    , fromByteString "\n"
+    ]
+
+showAddressHeader :: (S.ByteString, [Address]) -> Builder
+showAddressHeader (k, as) =
+  if null as
+  then mempty
+  else mconcat
+    [ fromByteString k
+    , fromByteString ": "
+    , mconcat (intersperse (fromByteString ", ") . map showAddress $ as)
+    , fromByteString "\n"
+    ]
+
+-- |
+--
+-- Since 0.4.3
+showAddress :: Address -> Builder
+showAddress a = mconcat
+    [ maybe mempty ((<> fromByteString " ") . encodedWord) (addressName a)
+    , fromByteString "<"
+    , fromText (sanitizeHeader $ addressEmail a)
+    , fromByteString ">"
+    ]
+
+-- Filter out control characters to prevent CRLF injection.
+sanitizeHeader :: Text -> Text
+sanitizeHeader = T.filter (not . isControl)
+
+showBoundPart :: Boundary -> (Headers, Builder) -> Builder
+showBoundPart (Boundary b) (headers, content) = mconcat
+    [ fromByteString "--"
+    , fromText b
+    , fromByteString "\n"
+    , mconcat $ map showHeader headers
+    , fromByteString "\n"
+    , content
+    ]
+
+showBoundEnd :: Boundary -> Builder
+showBoundEnd (Boundary b) = mconcat
+    [ fromByteString "\n--"
+    , fromText b
+    , fromByteString "--"
+    ]
+
+-- | Like 'renderMail', but generates a random boundary.
+renderMail' :: Mail -> IO L.ByteString
+renderMail' m = do
+    g <- getStdGen
+    let (lbs, g') = renderMail g m
+    setStdGen g'
+    return lbs
+
+-- | Send a fully-formed email message via the default sendmail
+-- executable with default options.
+sendmail :: L.ByteString -> IO ()
+sendmail = sendmailCustom sendmailPath ["-t"]
+
+sendmailPath :: String
+sendmailPath = "sendmail"
+
+-- | Render an email message and send via the default sendmail
+-- executable with default options.
+renderSendMail :: Mail -> IO ()
+renderSendMail = sendmail <=< renderMail'
+
+-- | Send a fully-formed email message via the specified sendmail
+-- executable with specified options.
+sendmailCustom :: FilePath        -- ^ sendmail executable path
+                  -> [String]     -- ^ sendmail command-line options
+                  -> L.ByteString -- ^ mail message as lazy bytestring
+                  -> IO ()
+sendmailCustom sm opts lbs = void $ sendmailCustomAux False sm opts lbs
+
+-- | Like 'sendmailCustom', but also returns sendmail's output to stderr and
+-- stdout as strict ByteStrings.
+--
+-- Since 0.4.9
+sendmailCustomCaptureOutput :: FilePath
+                               -> [String]
+                               -> L.ByteString
+                               -> IO (S.ByteString, S.ByteString)
+sendmailCustomCaptureOutput sm opts lbs = sendmailCustomAux True sm opts lbs
+
+sendmailCustomAux :: Bool
+                     -> FilePath
+                     -> [String]
+                     -> L.ByteString
+                     -> IO (S.ByteString, S.ByteString)
+sendmailCustomAux captureOut sm opts lbs = do
+    let baseOpts = (proc sm opts) { std_in = CreatePipe }
+        pOpts = if captureOut
+                    then baseOpts { std_out = CreatePipe
+                                  , std_err = CreatePipe
+                                  }
+                    else baseOpts
+    (Just hin, mHOut, mHErr, phandle) <- createProcess pOpts
+    L.hPut hin lbs
+    hClose hin
+    errMVar <- newEmptyMVar
+    outMVar <- newEmptyMVar
+    case (mHOut, mHErr) of
+        (Nothing, Nothing) -> return ()
+        (Just hOut, Just hErr) -> do
+            void . forkIO $ S.hGetContents hOut >>= putMVar outMVar
+            void . forkIO $ S.hGetContents hErr >>= putMVar errMVar
+        _ -> error "error in sendmailCustomAux: missing a handle"
+    exitCode <- waitForProcess phandle
+    case exitCode of
+        ExitSuccess -> if captureOut
+            then do
+                errOutput <- takeMVar errMVar
+                outOutput <- takeMVar outMVar
+                return (outOutput, errOutput)
+            else return (S.empty, S.empty)
+        _ -> throwIO $ ErrorCall ("sendmail exited with error code " ++ show exitCode)
+
+-- | Render an email message and send via the specified sendmail
+-- executable with specified options.
+renderSendMailCustom :: FilePath    -- ^ sendmail executable path
+                        -> [String] -- ^ sendmail command-line options
+                        -> Mail     -- ^ mail to render and send
+                        -> IO ()
+renderSendMailCustom sm opts = sendmailCustom sm opts <=< renderMail'
+
+-- FIXME usage of FilePath below can lead to issues with filename encoding
+
+-- | A simple interface for generating an email with HTML and plain-text
+-- alternatives and some file attachments.
+--
+-- Note that we use lazy IO for reading in the attachment contents.
+simpleMail :: Address -- ^ to
+           -> Address -- ^ from
+           -> Text -- ^ subject
+           -> LT.Text -- ^ plain body
+           -> LT.Text -- ^ HTML body
+           -> [(Text, FilePath)] -- ^ content type and path of attachments
+           -> IO Mail
+simpleMail to from subject plainBody htmlBody attachments =
+      addAttachments attachments
+    . addPart [plainPart plainBody, htmlPart htmlBody]
+    $ mailFromToSubject from to subject
+
+-- | A simple interface for generating an email with only plain-text body.
+simpleMail' :: Address -- ^ to
+            -> Address -- ^ from
+            -> Text -- ^ subject
+            -> LT.Text -- ^ body
+            -> Mail
+simpleMail' to from subject body = addPart [plainPart body]
+                                 $ mailFromToSubject from to subject
+
+-- | A simple interface for generating an email with HTML and plain-text
+-- alternatives and some 'ByteString' attachments.
+--
+-- Since 0.4.7
+simpleMailInMemory :: Address -- ^ to
+           -> Address -- ^ from
+           -> Text -- ^ subject
+           -> LT.Text -- ^ plain body
+           -> LT.Text -- ^ HTML body
+           -> [(Text, Text, L.ByteString)] -- ^ content type, file name and contents of attachments
+           -> Mail
+simpleMailInMemory to from subject plainBody htmlBody attachments =
+      addAttachmentsBS attachments
+    . addPart [plainPart plainBody, htmlPart htmlBody]
+    $ mailFromToSubject from to subject
+
+mailFromToSubject :: Address -- ^ from
+                  -> Address -- ^ to
+                  -> Text -- ^ subject
+                  -> Mail
+mailFromToSubject from to subject =
+    (emptyMail from) { mailTo = [to]
+                     , mailHeaders = [("Subject", subject)]
+                     }
+
+-- | Add an 'Alternative' to the 'Mail's parts.
+--
+-- To e.g. add a plain text body use
+-- > addPart [plainPart body] (emptyMail from)
+addPart :: Alternatives -> Mail -> Mail
+addPart alt mail = mail { mailParts = mailParts mail ++ [alt] }
+
+-- | Construct a UTF-8-encoded plain-text 'Part'.
+plainPart :: LT.Text -> Part
+plainPart body = Part cType QuotedPrintableText Nothing [] $ LT.encodeUtf8 body
+  where cType = "text/plain; charset=utf-8"
+
+-- | Construct a UTF-8-encoded html 'Part'.
+htmlPart :: LT.Text -> Part
+htmlPart body = Part cType QuotedPrintableText Nothing [] $ LT.encodeUtf8 body
+  where cType = "text/html; charset=utf-8"
+
+-- | Add an attachment from a file and construct a 'Part'.
+addAttachment :: Text -> FilePath -> Mail -> IO Mail
+addAttachment ct fn mail = do
+    part <- getAttachmentPart ct fn
+    return $ addPart [part] mail
+
+-- | Add an attachment from a file and construct a 'Part'
+-- with the specified content id in the Content-ID header.
+--
+-- @since 0.4.12
+addAttachmentCid :: Text -- ^ content type
+                 -> FilePath -- ^ file name
+                 -> Text -- ^ content ID
+                 -> Mail
+                 -> IO Mail
+addAttachmentCid ct fn cid mail =
+  getAttachmentPart ct fn >>= (return.addToMail.addHeader)
+  where
+    addToMail part = addPart [part] mail
+    addHeader part = part { partHeaders = header:ph }
+      where ph = partHeaders part
+    header = ("Content-ID", T.concat ["<", cid, ">"])
+
+addAttachments :: [(Text, FilePath)] -> Mail -> IO Mail
+addAttachments xs mail = foldM fun mail xs
+  where fun m (c, f) = addAttachment c f m
+
+-- | Add an attachment from a 'ByteString' and construct a 'Part'.
+--
+-- Since 0.4.7
+addAttachmentBS :: Text -- ^ content type
+                -> Text -- ^ file name
+                -> L.ByteString -- ^ content
+                -> Mail -> Mail
+addAttachmentBS ct fn content mail =
+    let part = getAttachmentPartBS ct fn content
+    in addPart [part] mail
+
+-- | @since 0.4.12
+addAttachmentBSCid :: Text -- ^ content type
+                -> Text -- ^ file name
+                -> L.ByteString -- ^ content
+                -> Text -- ^ content ID
+                -> Mail -> Mail
+addAttachmentBSCid ct fn content cid mail =
+    let part = addHeader $ getAttachmentPartBS ct fn content
+    in addPart [part] mail
+    where
+      addHeader part = part { partHeaders = header:ph }
+        where ph = partHeaders part
+      header = ("Content-ID", T.concat ["<", cid, ">"])
+
+-- |
+-- Since 0.4.7
+addAttachmentsBS :: [(Text, Text, L.ByteString)] -> Mail -> Mail
+addAttachmentsBS xs mail = foldl fun mail xs
+  where fun m (ct, fn, content) = addAttachmentBS ct fn content m
+
+getAttachmentPartBS :: Text
+                    -> Text
+                    -> L.ByteString
+                    -> Part
+getAttachmentPartBS ct fn content = Part ct Base64 (Just fn) [] content
+
+getAttachmentPart :: Text -> FilePath -> IO Part
+getAttachmentPart ct fn = do
+    content <- L.readFile fn
+    return $ getAttachmentPartBS ct (T.pack (takeFileName fn)) content
+
+data QP = QPPlain S.ByteString
+        | QPNewline
+        | QPTab
+        | QPSpace
+        | QPEscape S.ByteString
+
+data QPC = QPCCR
+         | QPCLF
+         | QPCSpace
+         | QPCTab
+         | QPCPlain
+         | QPCEscape
+    deriving Eq
+
+toQP :: Bool -- ^ text?
+     -> L.ByteString
+     -> [QP]
+toQP isText =
+    go
+  where
+    go lbs =
+        case L.uncons lbs of
+            Nothing -> []
+            Just (c, rest) ->
+                case toQPC c of
+                    QPCCR -> go rest
+                    QPCLF -> QPNewline : go rest
+                    QPCSpace -> QPSpace : go rest
+                    QPCTab -> QPTab : go rest
+                    QPCPlain ->
+                        let (x, y) = L.span ((== QPCPlain) . toQPC) lbs
+                         in QPPlain (toStrict x) : go y
+                    QPCEscape ->
+                        let (x, y) = L.span ((== QPCEscape) . toQPC) lbs
+                         in QPEscape (toStrict x) : go y
+
+    toStrict = S.concat . L.toChunks
+
+    toQPC :: Word8 -> QPC
+    toQPC 13 | isText = QPCCR
+    toQPC 10 | isText = QPCLF
+    toQPC 9 = QPCTab
+    toQPC 0x20 = QPCSpace
+    toQPC 46 = QPCEscape
+    toQPC 61 = QPCEscape
+    toQPC w
+        | 33 <= w && w <= 126 = QPCPlain
+        | otherwise = QPCEscape
+
+buildQPs :: [QP] -> Builder
+buildQPs =
+    go (0 :: Int)
+  where
+    go _ [] = mempty
+    go currLine (qp:qps) =
+        case qp of
+            QPNewline -> copyByteString "\r\n" `mappend` go 0 qps
+            QPTab -> wsHelper (copyByteString "=09") (fromWord8 9)
+            QPSpace -> wsHelper (copyByteString "=20") (fromWord8 0x20)
+            QPPlain bs ->
+                let toTake = 75 - currLine
+                    (x, y) = S.splitAt toTake bs
+                    rest
+                        | S.null y = qps
+                        | otherwise = QPPlain y : qps
+                 in helper (S.length x) (copyByteString x) (S.null y) rest
+            QPEscape bs ->
+                let toTake = (75 - currLine) `div` 3
+                    (x, y) = S.splitAt toTake bs
+                    rest
+                        | S.null y = qps
+                        | otherwise = QPEscape y : qps
+                 in if toTake == 0
+                        then copyByteString "=\r\n" `mappend` go 0 (qp:qps)
+                        else helper (S.length x * 3) (escape x) (S.null y) rest
+      where
+        escape =
+            S.foldl' add mempty
+          where
+            add builder w =
+                builder `mappend` escaped
+              where
+                escaped = fromWord8 61 `mappend` hex (w `shiftR` 4)
+                                       `mappend` hex (w .&. 15)
+
+        helper added builder noMore rest =
+            builder' `mappend` go newLine rest
+           where
+             (newLine, builder')
+                | not noMore || (added + currLine) >= 75 =
+                    (0, builder `mappend` copyByteString "=\r\n")
+                | otherwise = (added + currLine, builder)
+
+        wsHelper enc raw
+            | null qps =
+                if currLine <= 73
+                    then enc
+                    else copyByteString "\r\n=" `mappend` enc
+            | otherwise = helper 1 raw (currLine < 76) qps
+
+-- | The first parameter denotes whether the input should be treated as text.
+-- If treated as text, then CRs will be stripped and LFs output as CRLFs. If
+-- binary, then CRs and LFs will be escaped.
+quotedPrintable :: Bool -> L.ByteString -> Builder
+quotedPrintable isText = buildQPs . toQP isText
+
+hex :: Word8 -> Builder
+hex x
+    | x < 10 = fromWord8 $ x + 48
+    | otherwise = fromWord8 $ x + 55
+
+encodeIfNeeded :: Text -> Builder
+encodeIfNeeded t =
+  if needsEncodedWord t
+  then encodedWord t
+  else fromText t
+
+needsEncodedWord :: Text -> Bool
+needsEncodedWord = not . T.all isAscii
+
+encodedWord :: Text -> Builder
+encodedWord t = mconcat
+    [ fromByteString "=?utf-8?Q?"
+    , S.foldl' go mempty $ TE.encodeUtf8 t
+    , fromByteString "?="
+    ]
+  where
+    go front w = front `mappend` go' w
+    go' 32 = fromWord8 95 -- space
+    go' 95 = go'' 95 -- _
+    go' 63 = go'' 63 -- ?
+    go' 61 = go'' 61 -- =
+
+    -- The special characters from RFC 2822. Not all of these always give
+    -- problems, but at least @[];"<>, gave problems with some mail servers
+    -- when used in the 'name' part of an address.
+    go' 34 = go'' 34 -- "
+    go' 40 = go'' 40 -- (
+    go' 41 = go'' 41 -- )
+    go' 44 = go'' 44 -- ,
+    go' 46 = go'' 46 -- .
+    go' 58 = go'' 58 -- ;
+    go' 59 = go'' 59 -- ;
+    go' 60 = go'' 60 -- <
+    go' 62 = go'' 62 -- >
+    go' 64 = go'' 64 -- @
+    go' 91 = go'' 91 -- [
+    go' 92 = go'' 92 -- \
+    go' 93 = go'' 93 -- ]
+    go' w
+        | 33 <= w && w <= 126 = fromWord8 w
+        | otherwise = go'' w
+    go'' w = fromWord8 61 `mappend` hex (w `shiftR` 4)
+                          `mappend` hex (w .&. 15)
+
+-- 57 bytes, when base64-encoded, becomes 76 characters.
+-- Perform the encoding 57-bytes at a time, and then append a newline.
+base64 :: L.ByteString -> Builder
+base64 lbs
+    | L.null lbs = mempty
+    | otherwise = fromByteString x64 `mappend`
+                  fromByteString "\r\n" `mappend`
+                  base64 y
+  where
+    (x', y) = L.splitAt 57 lbs
+    x = S.concat $ L.toChunks x'
+    x64 = Base64.encode x
diff --git a/server/src/Model/Category.hs b/server/src/Model/Category.hs
new file mode 100644
index 0000000..6b7a488
--- /dev/null
+++ b/server/src/Model/Category.hs
@@ -0,0 +1,79 @@
+{-# LANGUAGE OverloadedStrings    #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+
+module Model.Category
+  ( list
+  , create
+  , edit
+  , delete
+  ) where
+
+import Data.Maybe (isJust, listToMaybe)
+import Data.Text (Text)
+import Data.Time.Clock (getCurrentTime)
+import Database.SQLite.Simple (Only(Only), FromRow(fromRow))
+import qualified Database.SQLite.Simple as SQLite
+import Prelude hiding (id)
+
+import Common.Model (Category(..), CategoryId)
+
+import Model.Query (Query(Query))
+
+instance FromRow Category where
+  fromRow = Category <$>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field
+
+list :: Query [Category]
+list =
+  Query (\conn ->
+    SQLite.query_ conn "SELECT * FROM category WHERE deleted_at IS NULL"
+  )
+
+create :: Text -> Text -> Query CategoryId
+create categoryName categoryColor =
+  Query (\conn -> do
+    now <- getCurrentTime
+    SQLite.execute
+      conn
+      "INSERT INTO category (name, color, created_at) VALUES (?, ?, ?)"
+      (categoryName, categoryColor, now)
+    SQLite.lastInsertRowId conn
+  )
+
+edit :: CategoryId -> Text -> Text -> Query Bool
+edit categoryId categoryName categoryColor =
+  Query (\conn -> do
+    mbCategory <- listToMaybe <$>
+      (SQLite.query conn "SELECT * FROM category WHERE id = ?" (Only categoryId) :: IO [Category])
+    if isJust mbCategory
+      then do
+        now <- getCurrentTime
+        SQLite.execute
+          conn
+          "UPDATE category SET edited_at = ?, name = ?, color = ? WHERE id = ?"
+          (now, categoryName, categoryColor, categoryId)
+        return True
+      else
+        return False
+  )
+
+delete :: CategoryId -> Query Bool
+delete categoryId =
+  Query (\conn -> do
+    mbCategory <- listToMaybe <$>
+      (SQLite.query conn "SELECT * FROM category WHERE id = ?" (Only categoryId) :: IO [Category])
+    if isJust mbCategory
+      then do
+        now <- getCurrentTime
+        SQLite.execute
+          conn
+          "UPDATE category SET deleted_at = ? WHERE id = ?" (now, categoryId)
+        return True
+      else
+        return False
+  )
diff --git a/server/src/Model/Frequency.hs b/server/src/Model/Frequency.hs
new file mode 100644
index 0000000..b334a40
--- /dev/null
+++ b/server/src/Model/Frequency.hs
@@ -0,0 +1,22 @@
+{-# LANGUAGE DeriveGeneric        #-}
+{-# LANGUAGE OverloadedStrings    #-}
+{-# LANGUAGE TemplateHaskell      #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+
+module Model.Frequency () where
+
+import Database.SQLite.Simple (SQLData(SQLText))
+import Database.SQLite.Simple.FromField (fieldData, FromField(fromField))
+import Database.SQLite.Simple.Ok (Ok(Ok, Errors))
+import Database.SQLite.Simple.ToField (ToField(toField))
+import qualified Data.Text as T
+
+import Common.Model (Frequency)
+
+instance FromField Frequency where
+  fromField field = case fieldData field of
+    SQLText text -> Ok (read (T.unpack text) :: Frequency)
+    _ -> Errors [error "SQLText field required for frequency"]
+
+instance ToField Frequency where
+  toField frequency = SQLText . T.pack . show $ frequency
diff --git a/server/src/Model/Income.hs b/server/src/Model/Income.hs
new file mode 100644
index 0000000..bbe7657
--- /dev/null
+++ b/server/src/Model/Income.hs
@@ -0,0 +1,97 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+
+module Model.Income
+  ( list
+  , create
+  , editOwn
+  , deleteOwn
+  , modifiedDuring
+  ) where
+
+import Data.Maybe (listToMaybe)
+import Data.Time.Calendar (Day)
+import Data.Time.Clock (UTCTime, getCurrentTime)
+import Database.SQLite.Simple (Only(Only), FromRow(fromRow))
+import Prelude hiding (id)
+import qualified Database.SQLite.Simple as SQLite
+
+import Common.Model (Income(..), IncomeId, User(..), UserId)
+
+import Model.Query (Query(Query))
+import Resource (Resource, resourceCreatedAt, resourceEditedAt, resourceDeletedAt)
+
+instance Resource Income where
+  resourceCreatedAt = _income_createdAt
+  resourceEditedAt = _income_editedAt
+  resourceDeletedAt = _income_deletedAt
+
+instance FromRow Income where
+  fromRow = Income <$>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field
+
+list :: Query [Income]
+list = Query (\conn -> SQLite.query_ conn "SELECT * FROM income WHERE deleted_at IS NULL")
+
+create :: UserId -> Day -> Int -> Query IncomeId
+create incomeUserId incomeDate incomeAmount =
+  Query (\conn -> do
+    now <- getCurrentTime
+    SQLite.execute
+      conn
+      "INSERT INTO income (user_id, date, amount, created_at) VALUES (?, ?, ?, ?)"
+      (incomeUserId, incomeDate, incomeAmount, now)
+    SQLite.lastInsertRowId conn
+  )
+
+editOwn :: UserId -> IncomeId -> Day -> Int -> Query Bool
+editOwn incomeUserId incomeId incomeDate incomeAmount =
+  Query (\conn -> do
+    mbIncome <- listToMaybe <$> SQLite.query conn "SELECT * FROM income WHERE id = ?" (Only incomeId)
+    case mbIncome of
+      Just income ->
+        if _income_userId income == incomeUserId
+          then do
+            now <- getCurrentTime
+            SQLite.execute
+              conn
+              "UPDATE income SET edited_at = ?, date = ?, amount = ? WHERE id = ?"
+              (now, incomeDate, incomeAmount, incomeId)
+            return True
+          else
+            return False
+      Nothing ->
+        return False
+  )
+
+deleteOwn :: User -> IncomeId -> Query Bool
+deleteOwn user incomeId =
+  Query (\conn -> do
+    mbIncome <- listToMaybe <$> SQLite.query conn "SELECT * FROM income WHERE id = ?" (Only incomeId)
+    case mbIncome of
+      Just income ->
+        if _income_userId income == _user_id user
+          then do
+            now <- getCurrentTime
+            SQLite.execute conn "UPDATE income SET deleted_at = ? WHERE id = ?" (now, incomeId)
+            return True
+          else
+            return False
+      Nothing ->
+        return False
+  )
+
+modifiedDuring :: UTCTime -> UTCTime -> Query [Income]
+modifiedDuring start end =
+  Query (\conn ->
+    SQLite.query
+      conn
+      "SELECT * FROM income WHERE (created_at >= ? AND created_at <= ?) OR (edited_at >= ? AND edited_at <= ?) OR (deleted_at >= ? AND deleted_at <= ?)"
+      (start, end, start, end, start, end)
+  )
diff --git a/server/src/Model/Init.hs b/server/src/Model/Init.hs
new file mode 100644
index 0000000..8c6a961
--- /dev/null
+++ b/server/src/Model/Init.hs
@@ -0,0 +1,27 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Model.Init
+  ( getInit
+  ) where
+
+import Common.Model (Init(Init), User(..))
+
+import Conf (Conf)
+import qualified Conf
+import Model.Query (Query)
+import qualified Model.Category as Category
+import qualified Model.Income as Income
+import qualified Model.Payment as Payment
+import qualified Model.PaymentCategory as PaymentCategory
+import qualified Model.User as User
+
+getInit :: User -> Conf -> Query Init
+getInit user conf =
+  Init <$>
+    User.list <*>
+    (return . _user_id $ user) <*>
+    Payment.list <*>
+    Income.list <*>
+    Category.list <*>
+    PaymentCategory.list <*>
+    (return . Conf.currency $ conf)
diff --git a/server/src/Model/Mail.hs b/server/src/Model/Mail.hs
new file mode 100644
index 0000000..9a4db73
--- /dev/null
+++ b/server/src/Model/Mail.hs
@@ -0,0 +1,12 @@
+module Model.Mail
+  ( Mail(..)
+  ) where
+
+import Data.Text (Text)
+
+data Mail = Mail
+  { from :: Text
+  , to :: [Text]
+  , subject :: Text
+  , plainBody :: Text
+  } deriving (Eq, Show)
diff --git a/server/src/Model/Payer.hs b/server/src/Model/Payer.hs
new file mode 100644
index 0000000..de4abd1
--- /dev/null
+++ b/server/src/Model/Payer.hs
@@ -0,0 +1,216 @@
+module Model.Payer
+  ( getOrderedExceedingPayers
+  ) where
+
+import Data.Map (Map)
+import Data.Time (UTCTime(..), NominalDiffTime)
+import qualified Data.List as List
+import qualified Data.Map as Map
+import qualified Data.Maybe as Maybe
+import qualified Data.Time as Time
+
+import Common.Model (User(..), UserId, Income(..), IncomeId, Payment(..))
+
+type Users = Map UserId User
+
+type Payers = Map UserId Payer
+
+type Incomes = Map IncomeId Income
+
+type Payments = [Payment]
+
+data Payer = Payer
+  { preIncomePaymentSum :: Int
+  , postIncomePaymentSum :: Int
+  , _incomes :: [Income]
+  }
+
+data PostPaymentPayer = PostPaymentPayer
+  { _preIncomePaymentSum :: Int
+  , _cumulativeIncome :: Int
+  , ratio :: Float
+  }
+
+data ExceedingPayer = ExceedingPayer
+  { _userId :: UserId
+  , amount :: Int
+  } deriving (Show)
+
+getOrderedExceedingPayers :: UTCTime -> [User] -> [Income] -> Payments -> [ExceedingPayer]
+getOrderedExceedingPayers currentTime users incomes payments =
+  let usersMap = Map.fromList . map (\user -> (_user_id user, user)) $ users
+      incomesMap = Map.fromList . map (\income -> (_income_id income, income)) $ incomes
+      payers = getPayers currentTime usersMap incomesMap payments
+      exceedingPayersOnPreIncome =
+        exceedingPayersFromAmounts
+          . Map.toList
+          . Map.map preIncomePaymentSum
+          $ payers
+      mbSince = useIncomesFrom usersMap incomesMap payments
+  in  case mbSince of
+        Just since ->
+          let postPaymentPayers = Map.map (getPostPaymentPayer currentTime since) payers
+              mbMaxRatio =
+                safeMaximum
+                  . map (ratio . snd)
+                  . Map.toList
+                  $ postPaymentPayers
+          in  case mbMaxRatio of
+                Just maxRatio ->
+                  exceedingPayersFromAmounts
+                    . Map.toList
+                    . Map.map (getFinalDiff maxRatio)
+                    $ postPaymentPayers
+                Nothing ->
+                  exceedingPayersOnPreIncome
+        _ ->
+          exceedingPayersOnPreIncome
+
+useIncomesFrom :: Users -> Incomes -> Payments -> Maybe UTCTime
+useIncomesFrom users incomes payments =
+  let firstPaymentTime = safeHead . List.sort . map paymentTime $ payments
+      mbIncomeTime = incomeDefinedForAll (Map.keys users) incomes
+  in  case (firstPaymentTime, mbIncomeTime) of
+        (Just t1, Just t2) -> Just (max t1 t2)
+        _ -> Nothing
+
+paymentTime :: Payment -> UTCTime
+paymentTime = flip UTCTime (Time.secondsToDiffTime 0) . _payment_date
+
+getPayers :: UTCTime -> Users -> Incomes -> Payments -> Payers
+getPayers currentTime users incomes payments =
+  let userIds = Map.keys users
+      incomesDefined = incomeDefinedForAll userIds incomes
+  in  Map.fromList
+        . map (\userId ->
+            ( userId
+            , Payer
+                { preIncomePaymentSum =
+                    totalPayments
+                      (\p -> paymentTime p < (Maybe.fromMaybe currentTime incomesDefined))
+                      userId
+                      payments
+                , postIncomePaymentSum =
+                    totalPayments
+                      (\p ->
+                        case incomesDefined of
+                          Nothing -> False
+                          Just t -> paymentTime p >= t
+                      )
+                      userId
+                      payments
+                , _incomes = filter ((==) userId . _income_userId) (Map.elems incomes)
+                }
+            )
+        )
+        $ userIds
+
+exceedingPayersFromAmounts :: [(UserId, Int)] -> [ExceedingPayer]
+exceedingPayersFromAmounts userAmounts =
+  case mbMinAmount of
+    Nothing ->
+      []
+    Just minAmount ->
+      filter (\payer -> amount payer > 0)
+        . map (\userAmount ->
+           ExceedingPayer
+             { _userId = fst userAmount
+             , amount = snd userAmount - minAmount
+             }
+        )
+        $ userAmounts
+  where mbMinAmount = safeMinimum . map snd $ userAmounts
+
+getPostPaymentPayer :: UTCTime -> UTCTime -> Payer -> PostPaymentPayer
+getPostPaymentPayer currentTime since payer =
+  PostPaymentPayer
+    { _preIncomePaymentSum = preIncomePaymentSum payer
+    , _cumulativeIncome = cumulativeIncome
+    , ratio = (fromIntegral . postIncomePaymentSum $ payer) / (fromIntegral cumulativeIncome)
+    }
+  where cumulativeIncome = cumulativeIncomesSince currentTime since (_incomes payer)
+
+getFinalDiff :: Float -> PostPaymentPayer -> Int
+getFinalDiff maxRatio payer =
+  let postIncomeDiff =
+        truncate $ -1.0 * (maxRatio - ratio payer) * (fromIntegral . _cumulativeIncome $ payer)
+  in  postIncomeDiff + _preIncomePaymentSum payer
+
+incomeDefinedForAll :: [UserId] -> Incomes -> Maybe UTCTime
+incomeDefinedForAll userIds incomes =
+  let userIncomes = map (\userId -> filter ((==) userId . _income_userId) . Map.elems $ incomes) userIds
+      firstIncomes = map (safeHead . List.sortOn incomeTime) userIncomes
+  in  if all Maybe.isJust firstIncomes
+        then safeHead . reverse . List.sort . map incomeTime . Maybe.catMaybes $ firstIncomes
+        else Nothing
+
+cumulativeIncomesSince :: UTCTime -> UTCTime -> [Income] -> Int
+cumulativeIncomesSince currentTime since incomes =
+  getCumulativeIncome currentTime (getOrderedIncomesSince since incomes)
+
+getOrderedIncomesSince :: UTCTime -> [Income] -> [Income]
+getOrderedIncomesSince time incomes =
+  let mbStarterIncome = getIncomeAt time incomes
+      orderedIncomesSince = filter (\income -> incomeTime income >= time) incomes
+  in  (Maybe.maybeToList mbStarterIncome) ++ orderedIncomesSince
+
+getIncomeAt :: UTCTime -> [Income] -> Maybe Income
+getIncomeAt time incomes =
+  case incomes of
+    [x] ->
+      if incomeTime x < time
+        then Just $ x { _income_date = utctDay time }
+        else Nothing
+    x1 : x2 : xs ->
+      if incomeTime x1 < time && incomeTime x2 >= time
+        then Just $ x1 { _income_date = utctDay time }
+        else getIncomeAt time (x2 : xs)
+    [] ->
+      Nothing
+
+getCumulativeIncome :: UTCTime -> [Income] -> Int
+getCumulativeIncome currentTime incomes =
+  sum
+    . map durationIncome
+    . getIncomesWithDuration currentTime
+    . List.sortOn incomeTime
+    $ incomes
+
+getIncomesWithDuration :: UTCTime -> [Income] -> [(NominalDiffTime, Int)]
+getIncomesWithDuration currentTime incomes =
+  case incomes of
+    [] ->
+      []
+    [income] ->
+      [(Time.diffUTCTime currentTime (incomeTime income), _income_amount income)]
+    (income1 : income2 : xs) ->
+      (Time.diffUTCTime (incomeTime income2) (incomeTime income1), _income_amount income1) : (getIncomesWithDuration currentTime (income2 : xs))
+
+incomeTime :: Income -> UTCTime
+incomeTime = flip UTCTime (Time.secondsToDiffTime 0) . _income_date
+
+durationIncome :: (NominalDiffTime, Int) -> Int
+durationIncome (duration, income) =
+  truncate $ duration * fromIntegral income / (nominalDay * 365 / 12)
+
+nominalDay :: NominalDiffTime
+nominalDay = 86400
+
+safeHead :: [a] -> Maybe a
+safeHead [] = Nothing
+safeHead (x : _) = Just x
+
+safeMinimum :: (Ord a) => [a] -> Maybe a
+safeMinimum [] = Nothing
+safeMinimum xs = Just . minimum $ xs
+
+safeMaximum :: (Ord a) => [a] -> Maybe a
+safeMaximum [] = Nothing
+safeMaximum xs = Just . maximum $ xs
+
+totalPayments :: (Payment -> Bool) -> UserId -> Payments -> Int
+totalPayments paymentFilter userId payments =
+  sum
+    . map _payment_cost
+    . filter (\payment -> paymentFilter payment && _payment_user payment == userId)
+    $ payments
diff --git a/server/src/Model/Payment.hs b/server/src/Model/Payment.hs
new file mode 100644
index 0000000..14efe77
--- /dev/null
+++ b/server/src/Model/Payment.hs
@@ -0,0 +1,175 @@
+{-# LANGUAGE OverloadedStrings    #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+
+module Model.Payment
+  ( Payment(..)
+  , find
+  , list
+  , listMonthly
+  , create
+  , createMany
+  , editOwn
+  , deleteOwn
+  , modifiedDuring
+  ) where
+
+import Data.Maybe (listToMaybe)
+import Data.Text (Text)
+import qualified Data.Text as T
+import Data.Time (UTCTime)
+import Data.Time.Calendar (Day)
+import Data.Time.Clock (getCurrentTime)
+import Database.SQLite.Simple (Only(Only), FromRow(fromRow), ToRow)
+import Database.SQLite.Simple.ToField (ToField(toField))
+import Prelude hiding (id)
+import qualified Database.SQLite.Simple as SQLite
+
+import Common.Model (Frequency(..), Payment(..), PaymentId, UserId)
+
+import Model.Frequency ()
+import Model.Query (Query(Query))
+import Resource (Resource, resourceCreatedAt, resourceEditedAt, resourceDeletedAt)
+
+instance Resource Payment where
+  resourceCreatedAt = _payment_createdAt
+  resourceEditedAt = _payment_editedAt
+  resourceDeletedAt = _payment_deletedAt
+
+instance FromRow Payment where
+  fromRow = Payment <$>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field
+
+instance ToRow Payment where
+  toRow p =
+    [ toField (_payment_user p)
+    , toField (_payment_name p)
+    , toField (_payment_cost p)
+    , toField (_payment_date p)
+    , toField (_payment_frequency p)
+    , toField (_payment_createdAt p)
+    ]
+
+find :: PaymentId -> Query (Maybe Payment)
+find paymentId =
+  Query (\conn -> listToMaybe <$>
+    SQLite.query conn "SELECT * FROM payment WHERE id = ?" (Only paymentId)
+  )
+
+list :: Query [Payment]
+list =
+  Query (\conn ->
+    SQLite.query_ conn "SELECT * FROM payment WHERE deleted_at IS NULL"
+  )
+
+listMonthly :: Query [Payment]
+listMonthly =
+  Query (\conn ->
+    SQLite.query
+      conn
+      (SQLite.Query $ T.intercalate " "
+        [ "SELECT *"
+        , "FROM payment"
+        , "WHERE deleted_at IS NULL AND frequency = ?"
+        , "ORDER BY name DESC"
+        ])
+      (Only Monthly)
+  )
+
+create :: UserId -> Text -> Int -> Day -> Frequency -> Query PaymentId
+create userId paymentName paymentCost paymentDate paymentFrequency =
+  Query (\conn -> do
+    now <- getCurrentTime
+    SQLite.execute
+      conn
+      (SQLite.Query $ T.intercalate " "
+        [ "INSERT INTO payment (user_id, name, cost, date, frequency, created_at)"
+        , "VALUES (?, ?, ?, ?, ?, ?)"
+        ])
+      (userId, paymentName, paymentCost, paymentDate, paymentFrequency, now)
+    SQLite.lastInsertRowId conn
+  )
+
+createMany :: [Payment] -> Query ()
+createMany payments =
+  Query (\conn ->
+    SQLite.executeMany
+      conn
+      (SQLite.Query $ T.intercalate ""
+        [ "INSERT INTO payment (user_id, name, cost, date, frequency, created_at)"
+        , "VALUES (?, ?, ?, ?, ?, ?)"
+        ])
+      payments
+  )
+
+editOwn :: UserId -> PaymentId -> Text -> Int -> Day -> Frequency -> Query Bool
+editOwn userId paymentId paymentName paymentCost paymentDate paymentFrequency =
+  Query (\conn -> do
+    mbPayment <- listToMaybe <$>
+      SQLite.query conn "SELECT * FROM payment WHERE id = ?" (Only paymentId)
+    case mbPayment of
+      Just payment ->
+        if _payment_user payment == userId
+          then do
+            now <- getCurrentTime
+            SQLite.execute
+              conn
+              (SQLite.Query $ T.intercalate " "
+                [ "UPDATE payment"
+                , "SET edited_at = ?,"
+                , "    name = ?,"
+                , "    cost = ?,"
+                , "    date = ?,"
+                , "    frequency = ?"
+                , "WHERE id = ?"
+                ])
+              (now, paymentName, paymentCost, paymentDate, paymentFrequency, paymentId)
+            return True
+          else
+            return False
+      Nothing ->
+        return False
+  )
+
+deleteOwn :: UserId -> PaymentId -> Query Bool
+deleteOwn userId paymentId =
+  Query (\conn -> do
+    mbPayment <- listToMaybe <$>
+      SQLite.query conn "SELECT * FROM payment WHERE id = ?" (Only paymentId)
+    case mbPayment of
+      Just payment ->
+        if _payment_user payment == userId
+          then do
+            now <- getCurrentTime
+            SQLite.execute
+              conn
+              "UPDATE payment SET deleted_at = ? WHERE id = ?"
+              (now, paymentId)
+            return True
+          else
+            return False
+      Nothing ->
+        return False
+  )
+
+modifiedDuring :: UTCTime -> UTCTime -> Query [Payment]
+modifiedDuring start end =
+  Query (\conn ->
+    SQLite.query
+      conn
+      (SQLite.Query $ T.intercalate " "
+        [ "SELECT *"
+        , "FROM payment"
+        , "WHERE (created_at >= ? AND created_at <= ?)"
+        , "   OR (edited_at >= ?  AND edited_at <= ?)"
+        , "   OR (deleted_at >= ? AND deleted_at <= ?)"
+        ])
+      (start, end, start, end, start, end)
+  )
diff --git a/server/src/Model/PaymentCategory.hs b/server/src/Model/PaymentCategory.hs
new file mode 100644
index 0000000..6e1d304
--- /dev/null
+++ b/server/src/Model/PaymentCategory.hs
@@ -0,0 +1,62 @@
+{-# LANGUAGE OverloadedStrings    #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+
+module Model.PaymentCategory
+  ( list
+  , listByCategory
+  , save
+  ) where
+
+import Data.Maybe (isJust, listToMaybe)
+import Data.Text (Text)
+import Data.Time.Clock (getCurrentTime)
+import Database.SQLite.Simple (Only(Only), FromRow(fromRow))
+import qualified Data.Text as T
+import qualified Database.SQLite.Simple as SQLite
+
+import Common.Model (CategoryId, PaymentCategory(..))
+import qualified Common.Util.Text as T
+
+import Model.Query (Query(Query))
+
+instance FromRow PaymentCategory where
+  fromRow = PaymentCategory <$>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field
+
+list :: Query [PaymentCategory]
+list = Query (\conn -> SQLite.query_ conn "SELECT * from payment_category")
+
+listByCategory :: CategoryId -> Query [PaymentCategory]
+listByCategory cat =
+  Query (\conn ->
+    SQLite.query conn "SELECT * FROM payment_category WHERE category = ?" (Only cat)
+  )
+
+save :: Text -> CategoryId -> Query ()
+save newName categoryId =
+  Query (\conn -> do
+    now <- getCurrentTime
+    mbPaymentCategory <- listToMaybe <$>
+      (SQLite.query
+        conn
+        "SELECT * FROM payment_category WHERE name = ?"
+        (Only (formatPaymentName newName)) :: IO [PaymentCategory])
+    if isJust mbPaymentCategory
+      then
+        SQLite.execute
+          conn
+          "UPDATE payment_category SET category = ?, edited_at = ? WHERE name = ?"
+          (categoryId, now, formatPaymentName newName)
+      else do
+        SQLite.execute
+          conn
+          "INSERT INTO payment_category (name, category, created_at) VALUES (?, ?, ?)"
+          (formatPaymentName newName, categoryId, now)
+  )
+  where
+    formatPaymentName :: Text -> Text
+    formatPaymentName = T.unaccent . T.toLower
diff --git a/server/src/Model/Query.hs b/server/src/Model/Query.hs
new file mode 100644
index 0000000..d15fb5f
--- /dev/null
+++ b/server/src/Model/Query.hs
@@ -0,0 +1,32 @@
+module Model.Query
+  ( Query(..)
+  , run
+  ) where
+
+import Data.Functor (Functor)
+import Database.SQLite.Simple (Connection)
+import qualified Database.SQLite.Simple as SQLite
+
+data Query a = Query (Connection -> IO a)
+
+instance Functor Query where
+  fmap f (Query call) = Query (fmap f . call)
+
+instance Applicative Query where
+  pure x = Query (const $ return x)
+  (Query callF) <*> (Query callX) = Query (\conn -> do
+    x <- callX conn
+    f <- callF conn
+    return (f x))
+
+instance Monad Query where
+  (Query callX) >>= f = Query (\conn -> do
+    x <- callX conn
+    case f x of Query callY -> callY conn)
+
+run :: Query a -> IO a
+run (Query call) = do
+  conn <- SQLite.open "database"
+  result <- call conn
+  _ <- SQLite.close conn
+  return result
diff --git a/server/src/Model/SignIn.hs b/server/src/Model/SignIn.hs
new file mode 100644
index 0000000..c5182f0
--- /dev/null
+++ b/server/src/Model/SignIn.hs
@@ -0,0 +1,66 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Model.SignIn
+  ( SignIn(..)
+  , createSignInToken
+  , getSignIn
+  , signInTokenToUsed
+  , isLastTokenValid
+  ) where
+
+import Data.Int (Int64)
+import Data.Maybe (listToMaybe)
+import Data.Text (Text)
+import Data.Time.Clock (getCurrentTime)
+import Data.Time.Clock (UTCTime)
+import Database.SQLite.Simple (Only(Only), FromRow(fromRow))
+import qualified Database.SQLite.Simple as SQLite
+
+import Model.Query (Query(Query))
+import Model.UUID (generateUUID)
+
+type SignInId = Int64
+
+data SignIn = SignIn
+  { id :: SignInId
+  , token :: Text
+  , creation :: UTCTime
+  , email :: Text
+  , isUsed :: Bool
+  } deriving Show
+
+instance FromRow SignIn where
+  fromRow = SignIn <$>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field <*>
+    SQLite.field
+
+createSignInToken :: Text -> Query Text
+createSignInToken signInEmail =
+  Query (\conn -> do
+    now <- getCurrentTime
+    signInToken <- generateUUID
+    SQLite.execute conn "INSERT INTO sign_in (token, creation, email, is_used) VALUES (?, ?, ?, ?)" (signInToken, now, signInEmail, False)
+    return signInToken
+  )
+
+getSignIn :: Text -> Query (Maybe SignIn)
+getSignIn signInToken =
+  Query (\conn -> do
+    listToMaybe <$> (SQLite.query conn "SELECT * from sign_in WHERE token = ? LIMIT 1" (Only signInToken) :: IO [SignIn])
+  )
+
+signInTokenToUsed :: SignInId -> Query ()
+signInTokenToUsed tokenId =
+  Query (\conn ->
+    SQLite.execute conn "UPDATE sign_in SET is_used = ? WHERE id = ?" (True, tokenId)
+  )
+
+isLastTokenValid :: SignIn -> Query Bool
+isLastTokenValid signIn =
+  Query (\conn -> do
+    [ Only lastToken ] <- SQLite.query conn "SELECT token from sign_in WHERE email = ? AND is_used = ? ORDER BY creation DESC LIMIT 1" (email signIn, True)
+    return . maybe False (== (token signIn)) $ lastToken
+  )
diff --git a/server/src/Model/UUID.hs b/server/src/Model/UUID.hs
new file mode 100644
index 0000000..6cb7ce0
--- /dev/null
+++ b/server/src/Model/UUID.hs
@@ -0,0 +1,10 @@
+module Model.UUID
+  ( generateUUID
+  ) where
+
+import Data.UUID (toString)
+import Data.UUID.V4 (nextRandom)
+import Data.Text (Text, pack)
+
+generateUUID :: IO Text
+generateUUID = pack . toString <$> nextRandom
diff --git a/server/src/Model/User.hs b/server/src/Model/User.hs
new file mode 100644
index 0000000..e14fcef
--- /dev/null
+++ b/server/src/Model/User.hs
@@ -0,0 +1,49 @@
+{-# LANGUAGE OverloadedStrings    #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+
+module Model.User
+  ( list
+  , get
+  , create
+  , delete
+  ) where
+
+import Data.Maybe (listToMaybe)
+import Data.Text (Text)
+import Data.Time.Clock (getCurrentTime)
+import Database.SQLite.Simple (Only(Only), FromRow(fromRow))
+import Prelude hiding (id)
+import qualified Database.SQLite.Simple as SQLite
+
+import Common.Model (UserId, User(..))
+
+import Model.Query (Query(Query))
+
+instance FromRow User where
+  fromRow = User <$> SQLite.field <*> SQLite.field <*> SQLite.field <*> SQLite.field
+
+list :: Query [User]
+list = Query (\conn -> SQLite.query_ conn "SELECT * from user ORDER BY creation DESC")
+
+get :: Text -> Query (Maybe User)
+get userEmail =
+  Query (\conn -> listToMaybe <$>
+    SQLite.query conn "SELECT * FROM user WHERE email = ? LIMIT 1" (Only userEmail)
+  )
+
+create :: Text -> Text -> Query UserId
+create userEmail userName =
+  Query (\conn -> do
+    now <- getCurrentTime
+    SQLite.execute
+      conn
+      "INSERT INTO user (creation, email, name) VALUES (?, ?, ?)"
+      (now, userEmail, userName)
+    SQLite.lastInsertRowId conn
+  )
+
+delete :: Text -> Query ()
+delete userEmail =
+  Query (\conn ->
+    SQLite.execute conn "DELETE FROM user WHERE email = ?" (Only userEmail)
+  )
diff --git a/server/src/Resource.hs b/server/src/Resource.hs
new file mode 100644
index 0000000..f52bbfa
--- /dev/null
+++ b/server/src/Resource.hs
@@ -0,0 +1,54 @@
+module Resource
+  ( Resource
+  , resourceCreatedAt
+  , resourceEditedAt
+  , resourceDeletedAt
+  , Status(..)
+  , statuses
+  , groupByStatus
+  , statusDuring
+  ) where
+
+import Data.Maybe (fromMaybe)
+import Data.Map (Map)
+import qualified Data.Map as M
+import Data.Time.Clock (UTCTime)
+
+class Resource a where
+  resourceCreatedAt :: a -> UTCTime
+  resourceEditedAt :: a -> Maybe UTCTime
+  resourceDeletedAt :: a -> Maybe UTCTime
+
+data Status =
+  Created
+  | Edited
+  | Deleted
+  deriving (Eq, Show, Read, Ord, Enum, Bounded)
+
+statuses :: [Status]
+statuses = [minBound..]
+
+groupByStatus :: Resource a => UTCTime -> UTCTime -> [a] -> Map Status [a]
+groupByStatus start end resources =
+  foldl
+    (\m resource ->
+      case statusDuring start end resource of
+        Just status -> M.insertWith (++) status [resource] m
+        Nothing -> m
+    )
+    M.empty
+    resources
+
+statusDuring :: Resource a => UTCTime -> UTCTime -> a -> Maybe Status
+statusDuring start end resource
+  | created && not deleted = Just Created
+  | not created && edited && not deleted = Just Edited
+  | not created && deleted = Just Deleted
+  | otherwise = Nothing
+  where
+    created = belongs (resourceCreatedAt resource) start end
+    edited = fromMaybe False (fmap (\t -> belongs t start end) $ resourceEditedAt resource)
+    deleted = fromMaybe False (fmap (\t -> belongs t start end) $ resourceDeletedAt resource)
+
+belongs :: UTCTime -> UTCTime -> UTCTime -> Bool
+belongs time start end = time >= start && time < end
diff --git a/server/src/Secure.hs b/server/src/Secure.hs
new file mode 100644
index 0000000..f427304
--- /dev/null
+++ b/server/src/Secure.hs
@@ -0,0 +1,47 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Secure
+  ( loggedAction
+  , getUserFromToken
+  ) where
+
+import Control.Monad.IO.Class (liftIO)
+import Data.Text (Text)
+import Data.Text.Lazy (fromStrict)
+import Network.HTTP.Types.Status (forbidden403)
+import Web.Scotty
+
+import qualified Common.Message as Message
+import qualified Common.Message.Key as Key
+import Common.Model (User)
+
+import Model.Query (Query)
+import qualified LoginSession
+import qualified Model.Query as Query
+import qualified Model.SignIn as SignIn
+import qualified Model.User as User
+
+loggedAction :: (User -> ActionM ()) -> ActionM ()
+loggedAction action = do
+  maybeToken <- LoginSession.get
+  case maybeToken of
+    Just token -> do
+      maybeUser <- liftIO . Query.run . getUserFromToken $ token
+      case maybeUser of
+        Just user ->
+          action user
+        Nothing -> do
+          status forbidden403
+          html . fromStrict . Message.get $ Key.Secure_Unauthorized
+    Nothing -> do
+      status forbidden403
+      html . fromStrict . Message.get $ Key.Secure_Forbidden
+
+getUserFromToken :: Text -> Query (Maybe User)
+getUserFromToken token = do
+  mbSignIn <- SignIn.getSignIn token
+  case mbSignIn of
+    Just signIn ->
+      User.get (SignIn.email signIn)
+    Nothing ->
+      return Nothing
diff --git a/server/src/SendMail.hs b/server/src/SendMail.hs
new file mode 100644
index 0000000..f7ba3fd
--- /dev/null
+++ b/server/src/SendMail.hs
@@ -0,0 +1,44 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module SendMail
+  ( sendMail
+  ) where
+
+import Control.Arrow (left)
+import Control.Exception (SomeException, try)
+import Data.Either (isLeft)
+
+import Data.Text (Text)
+import Data.Text.Lazy.Builder (toLazyText, fromText)
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as LT
+import qualified MimeMail as M
+
+import Model.Mail (Mail(Mail))
+
+sendMail :: Mail -> IO (Either Text ())
+sendMail mail = do
+  result <- left (T.pack . show) <$> (try (M.renderSendMail . getMimeMail $ mail) :: IO (Either SomeException ()))
+  if isLeft result
+    then putStrLn ("Error sending the following email:" ++ (show mail) ++ "\n" ++ (show result))
+    else putStrLn "OK"
+  return result
+
+getMimeMail :: Mail -> M.Mail
+getMimeMail (Mail mailFrom mailTo mailSubject mailPlainBody) =
+  let fromMail = M.emptyMail (address mailFrom)
+  in  fromMail
+        { M.mailTo = map address mailTo
+        , M.mailParts = [ [ M.plainPart . strictToLazy $ mailPlainBody ] ]
+        , M.mailHeaders = [("Subject", mailSubject)]
+        }
+
+address :: Text -> M.Address
+address addressEmail =
+  M.Address
+    { M.addressName = Nothing
+    , M.addressEmail = addressEmail
+    }
+
+strictToLazy :: Text -> LT.Text
+strictToLazy = toLazyText . fromText
diff --git a/server/src/Utils/Time.hs b/server/src/Utils/Time.hs
new file mode 100644
index 0000000..97457c7
--- /dev/null
+++ b/server/src/Utils/Time.hs
@@ -0,0 +1,25 @@
+module Utils.Time
+  ( belongToCurrentMonth
+  , belongToCurrentWeek
+  , timeToDay
+  ) where
+
+import Data.Time.Clock (UTCTime, getCurrentTime)
+import Data.Time.LocalTime
+import Data.Time.Calendar
+import Data.Time.Calendar.WeekDate (toWeekDate)
+
+belongToCurrentMonth :: UTCTime -> IO Bool
+belongToCurrentMonth time = do
+  (timeYear, timeMonth, _) <- toGregorian <$> timeToDay time
+  (actualYear, actualMonth, _) <- toGregorian <$> (getCurrentTime >>= timeToDay)
+  return (actualYear == timeYear && actualMonth == timeMonth)
+
+belongToCurrentWeek :: UTCTime -> IO Bool
+belongToCurrentWeek time = do
+  (timeYear, timeWeek, _) <- toWeekDate <$> timeToDay time
+  (actualYear, actualWeek, _) <- toWeekDate <$> (getCurrentTime >>= timeToDay)
+  return (actualYear == timeYear && actualWeek == timeWeek)
+
+timeToDay :: UTCTime -> IO Day
+timeToDay time = localDay . (flip utcToLocalTime time) <$> getTimeZone time
diff --git a/server/src/Validation.hs b/server/src/Validation.hs
new file mode 100644
index 0000000..1f332c9
--- /dev/null
+++ b/server/src/Validation.hs
@@ -0,0 +1,23 @@
+module Validation
+  ( nonEmpty
+  , number
+  ) where
+
+import Data.Text (Text)
+import qualified Data.Text as T
+
+nonEmpty :: Text -> Maybe Text
+nonEmpty str =
+  if T.null str
+   then Nothing
+   else Just str
+
+number :: (Int -> Bool) -> Text -> Maybe Int
+number numberForm str =
+  case reads (T.unpack str) :: [(Int, String)] of
+    (num, _) : _ ->
+      if numberForm num
+        then Just num
+        else Nothing
+    _ ->
+      Nothing
diff --git a/server/src/View/Mail/SignIn.hs b/server/src/View/Mail/SignIn.hs
new file mode 100644
index 0000000..1daca1e
--- /dev/null
+++ b/server/src/View/Mail/SignIn.hs
@@ -0,0 +1,24 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module View.Mail.SignIn
+  ( mail
+  ) where
+
+import Data.Text (Text)
+
+import qualified Common.Message as Message
+import qualified Common.Message.Key as Key
+import Common.Model (User(..))
+
+import Conf (Conf)
+import qualified Conf as Conf
+import qualified Model.Mail as M
+
+mail :: Conf -> User -> Text -> [Text] -> M.Mail
+mail conf user url to =
+  M.Mail
+    { M.from = Conf.noReplyMail conf
+    , M.to = to
+    , M.subject = Message.get Key.SignIn_MailTitle
+    , M.plainBody = Message.get (Key.SignIn_MailBody (_user_name user) url)
+    }
diff --git a/server/src/View/Mail/WeeklyReport.hs b/server/src/View/Mail/WeeklyReport.hs
new file mode 100644
index 0000000..b5f2b67
--- /dev/null
+++ b/server/src/View/Mail/WeeklyReport.hs
@@ -0,0 +1,102 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module View.Mail.WeeklyReport
+  ( mail
+  ) where
+
+import Data.List (sortOn)
+import Data.Map (Map)
+import Data.Maybe (catMaybes, fromMaybe)
+import Data.Monoid ((<>))
+import Data.Text (Text)
+import Data.Time.Clock (UTCTime)
+import qualified Data.Map as M
+import qualified Data.Text as T
+
+import qualified Common.Message as Message
+import qualified Common.Message.Key as Key
+import Common.Model (Payment(..), User(..), UserId, Income(..))
+import qualified Common.Model as CM
+import qualified Common.View.Format as Format
+
+import Model.Mail (Mail(Mail))
+import Model.Payment ()
+import qualified Model.Income ()
+import qualified Model.Mail as M
+import Resource (Status(..), groupByStatus, statuses)
+import Conf (Conf)
+import qualified Conf as Conf
+
+mail :: Conf -> [User] -> [Payment] -> [Income] -> UTCTime -> UTCTime -> Mail
+mail conf users payments incomes start end =
+  Mail
+    { M.from = Conf.noReplyMail conf
+    , M.to = map _user_email users
+    , M.subject = T.concat
+        [ Message.get Key.App_Title
+        , " − "
+        , Message.get Key.WeeklyReport_Title
+        ]
+    , M.plainBody = body conf users (groupByStatus start end payments) (groupByStatus start end incomes)
+    }
+
+body :: Conf -> [User] -> Map Status [Payment] -> Map Status [Income] -> Text
+body conf users paymentsByStatus incomesByStatus =
+  if M.null paymentsByStatus && M.null incomesByStatus
+    then
+      Message.get Key.WeeklyReport_Empty
+    else
+      T.intercalate "\n" . catMaybes . concat $
+        [ map (\s -> paymentSection s conf users <$> M.lookup s paymentsByStatus) statuses
+        , map (\s -> incomeSection s conf users <$> M.lookup s incomesByStatus) statuses
+        ]
+
+paymentSection :: Status -> Conf -> [User] -> [Payment] -> Text
+paymentSection status conf users payments =
+  section sectionTitle sectionItems
+  where count = length payments
+        sectionTitle = Message.get $ case status of
+          Created -> if count > 1 then Key.WeeklyReport_PaymentsCreated count else Key.WeeklyReport_PaymentCreated count
+          Edited -> if count > 1 then Key.WeeklyReport_PaymentsEdited count else Key.WeeklyReport_PaymentEdited count
+          Deleted -> if count > 1 then Key.WeeklyReport_PaymentsDeleted count else Key.WeeklyReport_PaymentDeleted count
+        sectionItems = map (payedFor status conf users) . sortOn _payment_date $ payments
+
+payedFor :: Status -> Conf -> [User] -> Payment -> Text
+payedFor status conf users payment =
+  case status of
+    Deleted -> Message.get (Key.WeeklyReport_PayedForNot name amount for at)
+    _ -> Message.get (Key.WeeklyReport_PayedFor name amount for at)
+  where name = formatUserName (_payment_user payment) users
+        amount = Format.price (Conf.currency conf) . _payment_cost $ payment
+        for = _payment_name payment
+        at = Format.longDay $ _payment_date payment
+
+incomeSection :: Status -> Conf -> [User] -> [Income] -> Text
+incomeSection status conf users incomes =
+  section sectionTitle sectionItems
+  where count = length incomes
+        sectionTitle = Message.get $ case status of
+          Created -> if count > 1 then Key.WeeklyReport_IncomesCreated count else Key.WeeklyReport_IncomeCreated count
+          Edited -> if count > 1 then Key.WeeklyReport_IncomesEdited count else Key.WeeklyReport_IncomeEdited count
+          Deleted -> if count > 1 then Key.WeeklyReport_IncomesDeleted count else Key.WeeklyReport_IncomeDeleted count
+        sectionItems = map (isPayedFrom status conf users) . sortOn _income_date $ incomes
+
+isPayedFrom :: Status -> Conf -> [User] -> Income -> Text
+isPayedFrom status conf users income =
+  case status of
+    Deleted -> Message.get (Key.WeeklyReport_PayedFromNot name amount for)
+    _ -> Message.get (Key.WeeklyReport_PayedFrom name amount for)
+  where name = formatUserName (_income_userId income) users
+        amount = Format.price (Conf.currency conf) . _income_amount $ income
+        for = Format.longDay $ _income_date income
+
+formatUserName :: UserId -> [User] -> Text
+formatUserName userId = fromMaybe "−" . fmap _user_name . CM.findUser userId
+
+section :: Text -> [Text] -> Text
+section title items =
+  T.concat
+    [ title
+    , "\n\n"
+    , T.unlines . map ("  - " <>) $ items
+    ]
diff --git a/server/src/View/Page.hs b/server/src/View/Page.hs
new file mode 100644
index 0000000..6bf9527
--- /dev/null
+++ b/server/src/View/Page.hs
@@ -0,0 +1,43 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module View.Page
+  ( page
+  ) where
+
+import Data.Text.Internal.Lazy (Text)
+import Data.Text.Lazy.Encoding (decodeUtf8)
+import Data.Aeson (encode)
+import qualified Data.Aeson.Types as Json
+
+import Text.Blaze.Html
+import Text.Blaze.Html5
+import qualified Text.Blaze.Html5 as H
+import Text.Blaze.Html5.Attributes
+import qualified Text.Blaze.Html5.Attributes as A
+import Text.Blaze.Html.Renderer.Text (renderHtml)
+
+import qualified Common.Message as Message
+import qualified Common.Message.Key as Key
+import Common.Model (InitResult)
+
+import Design.Global (globalDesign)
+
+page :: InitResult -> Text
+page initResult =
+  renderHtml . docTypeHtml $ do
+    H.head $ do
+      meta ! charset "UTF-8"
+      meta ! name "viewport" ! content "width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0"
+      H.title (toHtml $ Message.get Key.App_Title)
+      script ! src "javascript/main.js" $ ""
+      jsonScript "init" initResult
+      link ! rel "stylesheet" ! type_ "text/css" ! href "css/reset.css"
+      link ! rel "icon" ! type_ "image/png" ! href "images/icon.png"
+      H.style $ toHtml globalDesign
+
+jsonScript :: Json.ToJSON a => Text -> a -> Html
+jsonScript scriptId json =
+  script
+    ! A.id (toValue scriptId)
+    ! type_ "application/json"
+    $ toHtml . decodeUtf8 . encode $ json