diff --git a/src/runtime-prototype/app/Main.hs b/src/runtime-prototype/app/Main.hs
index cf9c4cba..1d181c7b 100644
--- a/src/runtime-prototype/app/Main.hs
+++ b/src/runtime-prototype/app/Main.hs
@@ -1,15 +1,38 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+
 module Main where
 
-import StuntDouble
+import Control.Concurrent.Async (cancel)
+import Control.Exception (throwIO)
+import System.Environment (getEnv)
+import System.FilePath ((</>))
+import System.IO.Error (catchIOError, isDoesNotExistError)
+
 import Scheduler
+import StuntDouble
 
 ------------------------------------------------------------------------
 
+getDbPath :: IO FilePath
+getDbPath = do
+  getEnv "DETSYS_DB"
+    `catchIOError` \(e :: catchIOError) ->
+      if isDoesNotExistError e
+        then do
+          home <- getEnv "HOME"
+          return (home </> ".detsys.db")
+        else throwIO e
+
 main :: IO ()
 main = do
   let executorPort = 3004
       executorRef = RemoteRef ("http://localhost:" ++ show executorPort) 0
-  el <- makeEventLoop realTime (makeSeed 0) HttpSync (EventLoopName "scheduler")
-  lref <- spawn el (fakeScheduler executorRef) initState
-  putStrLn "Scheduler is running..."
-  waitForEventLoopQuit el
+      schedulerPort = 3005
+  fp <- getDbPath
+  el <- makeEventLoop realTime (makeSeed 0) HttpSync (RealDisk fp) (EventLoopName "scheduler")
+  now <- getCurrentTime realTime
+  lref <- spawn el (fakeScheduler executorRef) (initState now (makeSeed 0))
+  withHttpFrontend el lref schedulerPort $ \pid -> do
+    putStrLn ("Scheduler is listening on port: " ++ show schedulerPort)
+    waitForEventLoopQuit el
+    cancel pid
diff --git a/src/runtime-prototype/src/Scheduler.hs b/src/runtime-prototype/src/Scheduler.hs
index 88274b82..ce24c3c8 100644
--- a/src/runtime-prototype/src/Scheduler.hs
+++ b/src/runtime-prototype/src/Scheduler.hs
@@ -1,12 +1,16 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE DeriveGeneric #-}
 
 module Scheduler where
 
 import Control.Concurrent.Async
 import Control.Exception
+import Data.Aeson
+import GHC.Generics (Generic)
 import Data.Heap (Entry(Entry), Heap)
 import qualified Data.Heap as Heap
 import Data.Text (Text)
+import qualified Data.Text.Encoding as Text
 import qualified Data.Text as Text
 import Data.Time (UTCTime)
 import Database.SQLite.Simple
@@ -15,10 +19,20 @@ import StuntDouble
 
 ------------------------------------------------------------------------
 
-data SchedulerCommand = SchedulerCommand
+data SchedulerEvent = SchedulerEvent
+  { kind  :: String
+  , event :: String
+  , args  :: Data.Aeson.Value
+  , to    :: String
+  , from  :: String
+  , at    :: UTCTime
+  }
+  deriving (Generic, Eq, Ord, Show)
+
+instance FromJSON SchedulerEvent where
 
 data SchedulerState = SchedulerState
-  { heap :: Heap (Entry UTCTime SchedulerCommand)
+  { heap :: Heap (Entry UTCTime SchedulerEvent)
   , time :: UTCTime
   , seed :: Seed
   }
@@ -30,19 +44,21 @@ initState t s = SchedulerState
   , seed = s
   }
 
-data Agenda = Agenda Int -- XXX
+data Agenda = Agenda [SchedulerEvent]
 
 instance ParseRow Agenda where
-  parseRow [FInt i] = Just (Agenda i)
-  parseRow _        = Nothing
+  parseRow [FText t] = case eitherDecodeStrict (Text.encodeUtf8 t) of
+    Right es -> Just (Agenda es)
+    Left err -> error (show err)
+  parseRow x         = error (show x)
 
 fakeScheduler :: RemoteRef -> Message -> Actor SchedulerState
 fakeScheduler executorRef (ClientRequest' "CreateTest" [SInt tid] cid) = Actor $ do
-  -- load from db. XXX: need to extend IO module to be able to return Datatype?
   p <- asyncIO (IOQuery "SELECT agenda FROM test_info WHERE test_id = :tid" [":tid" := tid])
-  on p (\(IOResultR (IORows entries)) -> case parseRows entries of
-           Just [Agenda i] -> undefined)
-  undefined
+  on p (\(IOResultR (IORows rs)) -> case parseRows rs of
+           Nothing          -> clientResponse cid (InternalMessage "parse error")
+           Just [Agenda es] -> clientResponse cid (InternalMessage (show es)))
+  return (InternalMessage "ok")
 fakeScheduler executorRef (ClientRequest "Start" cid) = Actor $ do
   -- pop agenda end send to executorRef
   r <- Heap.uncons . heap <$> get
@@ -56,7 +72,7 @@ fakeScheduler executorRef (ClientRequest "Start" cid) = Actor $ do
       undefined
     Nothing -> return (InternalMessage "Done") -- XXX: reply to client id?!
   where
-    prettyCommand :: SchedulerCommand -> String
+    prettyCommand :: SchedulerEvent -> String
     prettyCommand = undefined
 fakeScheduler executorRef msg@(InternalMessage "Ack") = Actor $ do
   undefined
diff --git a/src/runtime-prototype/src/StuntDouble/ActorMap.hs b/src/runtime-prototype/src/StuntDouble/ActorMap.hs
index 59ae11dd..4f5772e4 100644
--- a/src/runtime-prototype/src/StuntDouble/ActorMap.hs
+++ b/src/runtime-prototype/src/StuntDouble/ActorMap.hs
@@ -584,19 +584,21 @@ spawnIOWorkers (ThreadPoolOfSize n)  ls
         error "spawnIOWorkers: thread pool size is bigger than the available CPU capabilities"
       mapM (\c -> asyncOn c (asyncIOWorker ls)) [ i | i <- [0..n], i /= cap ]
 
-makeEventLoop :: Time -> Seed -> TransportKind -> EventLoopName -> IO EventLoop
+makeEventLoop :: Time -> Seed -> TransportKind -> DiskKind -> EventLoopName -> IO EventLoop
 makeEventLoop = makeEventLoopThreaded SingleThreaded NoThreadPool
 
-makeEventLoopThreaded :: Threaded -> ThreadPool -> Time -> Seed -> TransportKind
+makeEventLoopThreaded :: Threaded -> ThreadPool -> Time -> Seed -> TransportKind -> DiskKind
                       -> EventLoopName -> IO EventLoop
-makeEventLoopThreaded threaded threadpool time seed tk name = do
+makeEventLoopThreaded threaded threadpool time seed tk dk name = do
   t <- case tk of
          NamedPipe fp -> namedPipeTransport fp name
          Http port    -> httpTransport port
          HttpSync     -> httpSyncTransport
          Stm          -> stmTransport
-  disk <- fakeDisk
-  ls <- initLoopState name time seed t disk
+  d <- case dk of
+         FakeDisk    -> fakeDisk
+         RealDisk fp -> realDisk fp
+  ls <- initLoopState name time seed t d
   workerPids <- spawnIOWorkers threadpool ls
   pids <- case threaded of
             SingleThreaded ->
@@ -798,7 +800,7 @@ handleEvent (Admin cmd) ls = case cmd of
     threadDelay 100000
     mapM_ cancel pids
 handleEvent (ClientRequestEvent lref msg cref returnVar) ls = do
-  reply <- actorPokeIO ls lref (ClientRequest (getMessage msg) cref)
+  reply <- actorPokeIO ls lref (ClientRequest' (getMessage msg) (getArgs msg) cref)
   atomically (putTMVar returnVar reply)
 
 waitForEventLoopQuit :: EventLoop -> IO ()
diff --git a/src/runtime-prototype/src/StuntDouble/IO.hs b/src/runtime-prototype/src/StuntDouble/IO.hs
index 3ae0c0be..a41dce9d 100644
--- a/src/runtime-prototype/src/StuntDouble/IO.hs
+++ b/src/runtime-prototype/src/StuntDouble/IO.hs
@@ -6,6 +6,7 @@
 module StuntDouble.IO where
 
 import Control.Monad
+import Data.String
 import Data.HashMap.Strict (HashMap)
 import qualified Data.HashMap.Strict as HashMap
 import Data.Hashable
@@ -37,8 +38,8 @@ data IOOp
   | IODeletes [Key]
   | IOIterate Key Key
 
-  | IOExecute Query [NamedParam]
-  | IOQuery Query [NamedParam]
+  | IOExecute String [NamedParam]
+  | IOQuery String [NamedParam]
 
   | IOReturn IOResult
 
@@ -52,8 +53,8 @@ data Disk m = Disk
   , ioIterate :: Maybe Key -> Maybe Key -> m [(Key, Value)]
 
   -- SQLite.
-  , ioExecute :: Query -> [NamedParam] -> m ()
-  , ioQuery   :: Query -> [NamedParam] -> m [[FieldValue]]
+  , ioExecute :: String -> [NamedParam] -> m ()
+  , ioQuery   :: String -> [NamedParam] -> m [[FieldValue]]
   }
 
 data FieldValue
@@ -106,8 +107,8 @@ fakeDisk = do
 slowFakeDisk :: IO (Disk IO)
 slowFakeDisk = undefined
 
-realSqlite :: FilePath -> IO (Disk IO)
-realSqlite fp = do
+realDisk :: FilePath -> IO (Disk IO)
+realDisk fp = do
   conn <- open fp
   return Disk
     { ioGet     = undefined
@@ -117,19 +118,26 @@ realSqlite fp = do
     , ioDeletes = undefined
     , ioIterate = undefined
 
-    , ioExecute = executeNamed conn
-    , ioQuery   = queryNamed   conn
+    , ioExecute = \q -> executeNamed conn (fromString q)
+    , ioQuery   = \q -> queryNamed   conn (fromString q)
     }
 
 class ParseRow a where
   parseRow :: [FieldValue] -> Maybe a
 
 instance ParseRow [FieldValue] where
+  parseRow :: [FieldValue] -> Maybe [FieldValue]
   parseRow = Just
 
 instance ParseRow FieldValue where
+  parseRow :: [FieldValue] -> Maybe FieldValue
   parseRow [fv] = Just fv
   parseRow _    = Nothing
 
 parseRows :: ParseRow a => [[FieldValue]] -> Maybe [a]
 parseRows = sequence . map parseRow
+
+
+data DiskKind
+  = FakeDisk
+  | RealDisk FilePath
diff --git a/src/runtime-prototype/src/StuntDouble/Message.hs b/src/runtime-prototype/src/StuntDouble/Message.hs
index 0781cc57..70752e2a 100644
--- a/src/runtime-prototype/src/StuntDouble/Message.hs
+++ b/src/runtime-prototype/src/StuntDouble/Message.hs
@@ -31,3 +31,9 @@ getMessage (InternalMessage msg) = msg
 getMessage (InternalMessage' msg _args) = msg
 getMessage (ClientRequest msg _cid) = msg
 getMessage (ClientRequest' msg _args _cid) = msg
+
+getArgs :: Message -> Args
+getArgs InternalMessage {}               = []
+getArgs (InternalMessage' _msg args)     = args
+getArgs ClientRequest {}                 = []
+getArgs (ClientRequest' _msg args _cref) = args
diff --git a/src/runtime-prototype/stunt-double.cabal b/src/runtime-prototype/stunt-double.cabal
index 29cd5424..37b9a81b 100644
--- a/src/runtime-prototype/stunt-double.cabal
+++ b/src/runtime-prototype/stunt-double.cabal
@@ -107,7 +107,9 @@ test-suite test
 executable scheduler
   hs-source-dirs:   app/
   main-is:          Main.hs
-  build-depends:    base ==4.13.*,
+  build-depends:    async,
+                    base ==4.13.*,
+                    filepath,
                     stunt-double
   ghc-options:      -threaded -rtsopts -with-rtsopts=-N
   default-language: Haskell2010