diff --git a/HappsCommand.hs b/HappsCommand.hs
new file mode 100644
index 000000000..6a38ca4aa
--- /dev/null
+++ b/HappsCommand.hs
@@ -0,0 +1,39 @@
+{-| 
+
+A happs-based UI for hledger.
+
+-}
+
+module HappsCommand
+where
+import qualified Data.Map as Map
+import Data.Map ((!))
+import HAppS.Server
+import Ledger
+import Options
+import BalanceCommand
+import RegisterCommand
+import PrintCommand
+
+
+-- | The application state when running the ui command.
+data AppState = AppState {
+     aw :: Int                   -- ^ window width
+    ,ah :: Int                   -- ^ window height
+    ,amsg :: String              -- ^ status message
+    ,aopts :: [Opt]              -- ^ command-line opts
+    ,aargs :: [String]           -- ^ command-line args
+    ,aledger :: Ledger           -- ^ parsed ledger
+    ,abuf :: [String]            -- ^ lines of the current buffered view
+                                -- ^ never null, head is current location
+    } deriving (Show)
+
+tcpport = 5000
+
+happs :: [Opt] -> [String] -> Ledger -> IO ()
+happs opts args l = do
+  putStrLn $ printf "hledger server running on port %d" tcpport
+  simpleHTTP nullConf{port=tcpport} [
+                     method GET $ ok $ toResponse $ output
+                    ]
+      where output = showBalanceReport (opts++[SubTotal]) [] l
diff --git a/Makefile b/Makefile
index 5b34c9cad..4fa2ec468 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 
 # build the normal hledger binary
 BUILD=ghc --make hledger.hs -o hledger -O
-BUILDFLAGS=-DVTY -DANSI
+BUILDFLAGS=-DVTY -DANSI -DHAPPS
 build: setbuildversion tag
 	$(BUILD) $(BUILDFLAGS)
 
diff --git a/README b/README
index b50866bea..4b8145337 100644
--- a/README
+++ b/README
@@ -37,10 +37,11 @@ features. These are::
 
   -f vty   - Build vty-based text ui (requires vty, not available on windows)
   -f ansi  - Build ansi-based text ui (requires ansi-terminal)
+  -f happs - Build happs-based web ui (requires HApps-Server)
 
 Eg::
 
- cabal install -f "vty ansi" hledger (or runhaskell Setup.hs configure -f "vty ansi")
+ cabal install -f "vty ansi happs" hledger (or runhaskell Setup.hs configure -f "vty ansi happs")
 
 To get the latest development code do::
 
diff --git a/hledger.cabal b/hledger.cabal
index 557801fb1..88bcbf45b 100644
--- a/hledger.cabal
+++ b/hledger.cabal
@@ -24,6 +24,9 @@ Flag vty
 Flag ansi
   description: Build ansi-based text ui (requires ansi-terminal)
   default:     False
+Flag happs
+  description: Build happs-based web ui (requires HApps-Server)
+  default:     False
 
 Executable hledger
   Main-Is:        hledger.hs
@@ -69,6 +72,10 @@ Executable hledger
     Build-Depends:ansi-terminal
     Other-Modules:ANSICommand
     cpp-options: -DANSI
+  if flag(happs)
+    Build-Depends:HAppS-Server>=0.9.3.1
+    Other-Modules:HappsCommand
+    cpp-options: -DHAPPS
 
 Library
   Build-Depends:  base, containers, haskell98, directory, parsec, regex-compat,
diff --git a/hledger.hs b/hledger.hs
index 9bfceb2ec..6be3cba0b 100644
--- a/hledger.hs
+++ b/hledger.hs
@@ -58,6 +58,9 @@ import qualified UICommand
 #ifdef ANSI
 import qualified ANSICommand
 #endif
+#ifdef HAPPS
+import qualified HappsCommand
+#endif
 import Tests
 
 
@@ -77,6 +80,9 @@ main = do
 #endif
 #ifdef ANSI
        | cmd `isPrefixOf` "ansi"     = parseLedgerAndDo opts args ANSICommand.ansi
+#endif
+#ifdef HAPPS
+       | cmd `isPrefixOf` "happs"    = parseLedgerAndDo opts args HappsCommand.happs
 #endif
        | cmd `isPrefixOf` "test"     = runtests opts args >> return ()
        | otherwise                   = putStr $ usage