diff --git a/src/PostgREST/DbStructure.hs b/src/PostgREST/DbStructure.hs
index b57f5d398..b677f7090 100644
--- a/src/PostgREST/DbStructure.hs
+++ b/src/PostgREST/DbStructure.hs
@@ -16,7 +16,7 @@ import           Control.Applicative
 import           Data.List                     (elemIndex)
 import           Data.Maybe                    (fromJust)
 import           Data.Monoid
-import           Data.Text                     (split)
+import           Data.Text                     (split, strip)
 import qualified Hasql.Session                 as H
 import           PostgREST.Types
 import           Text.InterpolatedString.Perl6 (q)
@@ -99,12 +99,21 @@ accessibleProcs :: H.Query Schema [(Text, ProcDescription)]
 accessibleProcs =
   H.statement sql (HE.value HE.text)
     (map addName <$> HD.rowsList (ProcDescription <$> HD.value HD.text
-                                  <*> HD.value HD.text
-                                  <*> HD.value HD.text)) True
+                                <*> (parseArgs <$> HD.value HD.text)
+                                <*> HD.value HD.text)) True
  where
   addName :: ProcDescription -> (Text, ProcDescription)
   addName pd = (pdName pd, pd)
 
+  parseArgs :: Text -> [(PgArgName, PgArgType)]
+  parseArgs = mapMaybe list2pair
+                . map (split (==' ') . strip)
+                . split (==',')
+
+  list2pair :: [a] -> Maybe (a,a)
+  list2pair (x:y:_) = Just (x,y)
+  list2pair _       = Nothing
+
   sql = [q|
     SELECT p.proname as "proc_name",
            pg_get_function_arguments(p.oid) as "args",
diff --git a/src/PostgREST/OpenAPI.hs b/src/PostgREST/OpenAPI.hs
index daba8a247..50e1e330d 100644
--- a/src/PostgREST/OpenAPI.hs
+++ b/src/PostgREST/OpenAPI.hs
@@ -24,7 +24,8 @@ import           PostgREST.ApiRequest        (ContentType(..), toHeader)
 import           PostgREST.Config            (prettyVersion)
 import           PostgREST.QueryBuilder      (operators)
 import           PostgREST.Types             (Table(..), Column(..),
-                                              Proxy(..), ProcDescription(..))
+                                              Proxy(..), ProcDescription(..),
+                                              PgArgName, PgArgType)
 
 makeMimeList :: [ContentType] -> MimeList
 makeMimeList cs = MimeList $ map (fromString . toS . toHeader) cs
@@ -173,6 +174,20 @@ makePostParams tn =
     & schema .~ ParamBody (Ref (Reference tn))
   ]
 
+makeProcParams :: ProcDescription -> [Param]
+makeProcParams pd =
+  map (makeProcParam $ pdName pd) (pdArgs pd)
+
+makeProcParam :: Text -> (PgArgName, PgArgType) -> Param
+makeProcParam refName (n, t) =
+  (mempty :: Param)
+    & name        .~ n
+    & required    ?~ True
+    -- & schema .~ ParamBody ((Ref (Reference refName))
+    & schema .~ ParamOther ((mempty :: ParamOtherSchema)
+      -- & in_ .~ ParamQuery
+      & type_ .~ toSwaggerType t)
+
 makeDeleteParams :: [Param]
 makeDeleteParams =
   [ makePreferParam ["return=representation", "return=minimal", "return=none"] ]
@@ -208,7 +223,7 @@ makeProcPathItem :: ProcDescription -> (FilePath, PathItem)
 makeProcPathItem pd = ("/rpc/" ++ toS (pdName pd), pe)
   where
     postOp = (mempty :: Operation)
-      & parameters .~ []
+      & parameters .~ map Inline (makeProcParams pd)
       & tags .~ Set.fromList ["/rpc/" <> pdName pd]
       & produces ?~ makeMimeList [CTApplicationJSON]
       & at 200 ?~ "OK"
diff --git a/src/PostgREST/Types.hs b/src/PostgREST/Types.hs
index c5f30a099..7c5af1032 100644
--- a/src/PostgREST/Types.hs
+++ b/src/PostgREST/Types.hs
@@ -16,9 +16,12 @@ data DbStructure = DbStructure {
 , dbProcs       :: [(Text,ProcDescription)]
 } deriving (Show, Eq)
 
+type PgArgName = Text
+type PgArgType = Text
+
 data ProcDescription = ProcDescription {
   pdName       :: Text
-, pdArgs       :: Text
+, pdArgs       :: [(PgArgName, PgArgType)]
 , pdReturnType :: Text
 } deriving (Show, Eq)