diff --git a/ChangeLog.md b/ChangeLog.md
new file mode 100644
--- /dev/null
+++ b/ChangeLog.md
@@ -0,0 +1,5 @@
+# Changelog for sheets
+
+## 0.0.1.0
+
+* Added `SheetT` transformer, and `FromJSON`, `ToJSON` instances.
diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright Author name here (c) 2022
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Author name here nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
new file mode 100644
--- /dev/null
+++ b/README.md
@@ -0,0 +1,11 @@
+# sheets
+
+Sheets is a spreadsheet type using
+[composite-base](https://hackage.haskell.org/package/composite-base) and
+[composite-cassava](https://hackage.haskell.org/package/composite-cassava).
+Combined with [composite-ix](https://hackage.haskell.org/package/composite-ix),
+you can do indexing queries on composite records to group and aggregate data
+over multiple fields.
+
+Sheets also provides `FromJSON` and `ToJSON` instances using a base64 encoding
+to Text, so the entire CSV will fit in a single JSON text field.
diff --git a/sheets.cabal b/sheets.cabal
new file mode 100644
--- /dev/null
+++ b/sheets.cabal
@@ -0,0 +1,55 @@
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.34.6.
+--
+-- see: https://github.com/sol/hpack
+
+name:           sheets
+version:        0.1.0.0
+synopsis:       Spreadsheet type for composite.
+description:    Spreadsheet type for composite.
+category:       Web
+author:         Daniel Firth
+maintainer:     dan.firth@homotopic.tech
+copyright:      2022 Daniel Firth
+license:        BSD3
+license-file:   LICENSE
+build-type:     Simple
+extra-source-files:
+    README.md
+    ChangeLog.md
+
+source-repository head
+  type: git
+  location: https://gitlab.homotopic.tech/haskell/sheets
+
+library
+  exposed-modules:
+      Composite.Sheet
+  other-modules:
+      Paths_sheets
+  hs-source-dirs:
+      src
+  default-extensions:
+      AllowAmbiguousTypes
+      DeriveGeneric
+      DerivingStrategies
+      FlexibleContexts
+      FlexibleInstances
+      GADTs
+      RankNTypes
+      ScopedTypeVariables
+      StandaloneDeriving
+      TypeApplications
+      TypeOperators
+  build-depends:
+      aeson
+    , base >=4.7 && <5
+    , base64-bytestring
+    , bytestring
+    , cassava
+    , composite-base
+    , composite-cassava
+    , text
+    , vector
+  default-language: Haskell2010
diff --git a/src/Composite/Sheet.hs b/src/Composite/Sheet.hs
new file mode 100644
--- /dev/null
+++ b/src/Composite/Sheet.hs
@@ -0,0 +1,42 @@
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE UndecidableInstances #-}
+module Composite.Sheet where
+
+import qualified Composite.Csv          as Csv
+import           Composite.Record
+import           Control.Applicative
+import           Data.Aeson             as A
+import           Data.ByteString.Base64 as B64
+import           Data.ByteString.Lazy   (fromStrict, toStrict)
+import           Data.Csv               hiding (Record)
+import           Data.Functor.Identity
+import           Data.Proxy
+import           Data.Text.Encoding
+import qualified Data.Vector            as V
+import           GHC.Generics
+
+-- | The SheetT type. This is a functor of hetrogenous records.
+-- A typical "SpreadSheet" might be something like `SheetT [] Identity`
+-- This provides a convenient newtype for deriving instances.
+newtype SheetT w f xs = SheetT { runSheetT :: w (Rec f xs) }
+
+type Sheet f xs = SheetT f Identity xs
+
+deriving stock instance Eq (w (Rec f xs)) => Eq (SheetT w f xs)
+deriving stock instance Show (w (Rec f xs)) => Show (SheetT w f xs)
+deriving stock instance Generic (SheetT w f xs)
+
+instance (ToNamedRecord (Record ixs), Csv.ToHeader (Record ixs)) => ToJSON (Sheet [] ixs) where
+  toJSON (SheetT xs) =
+    let z = encodeByName (Csv.extractRecHeader (Proxy @(Record ixs))) xs
+     in A.String $ decodeUtf8 $ B64.encode $ toStrict $ z
+
+instance FromNamedRecord (Record ixs) => FromJSON (Sheet [] ixs) where
+  parseJSON (String x) = do
+   let k = case B64.decode $ encodeUtf8 x of
+             Left e  -> Left e
+             Right a -> decodeByName . fromStrict $ a
+   case k of
+     Left e  -> fail $ show e
+     Right a -> pure $ SheetT $ V.toList $ snd a
+  parseJSON _ = empty