diff --git a/hbs2-git3/app/Main.hs b/hbs2-git3/app/Main.hs
index be658ff8..a1b198eb 100644
--- a/hbs2-git3/app/Main.hs
+++ b/hbs2-git3/app/Main.hs
@@ -9,6 +9,7 @@ module Main where
 import HBS2.Prelude.Plated
 import HBS2.OrDie
 import HBS2.Base58
+import HBS2.Merkle
 
 import HBS2.Storage
 import HBS2.Peer.CLI.Detect
@@ -586,8 +587,23 @@ theDict = do
 
                               debug $ "pack-merkle-tree-hash" <+> pretty href
 
-                              withState do
+                              debug $ "make cblock"
+
+                              phashes <- withState $ for parents \p -> do
+                                             selectCBlock p
+                                              >>= orThrowUser ("pack export failed" <+> pretty p)
+
+                              debug $ "write cblock"
+
+                              let cblock = href : phashes
+                              let pt = toPTree (MaxSize 1024) (MaxNum 1024) cblock
+
+                              root <- makeMerkle 0 pt $ \(_,_,s) -> do
+                                         void $ putBlock sto s
+
+                              withState $ transactional do
                                 insertGitPack co href
+                                insertCBlock co (HashRef root)
 
                               atomically $ modifyTVar done (HS.insert co)
                             else do
@@ -597,7 +613,8 @@ theDict = do
 
                   ExportCheck -> do
                     debug $ "ExportCheck dummy" <+> pretty r
-                    debug "exit export"
+                    c <- lift $ withState $ selectCBlock r >>= orThrowUser "export failed"
+                    liftIO $ hPrint stdout (pretty c)
 
               -- case co' of
               --   Just co -> do
diff --git a/hbs2-git3/lib/HBS2/Git3/State/Direct.hs b/hbs2-git3/lib/HBS2/Git3/State/Direct.hs
index fc583f35..d1abe826 100644
--- a/hbs2-git3/lib/HBS2/Git3/State/Direct.hs
+++ b/hbs2-git3/lib/HBS2/Git3/State/Direct.hs
@@ -49,6 +49,15 @@ gitpack
   )
 |]
 
+    ddl [qc|
+create table if not exists
+cblock
+  ( kommit  text not null primary key
+  , cblock  text not null
+  )
+|]
+
+
 
 instance ToField GitHash where
   toField h = toField (show $ pretty h)
@@ -81,3 +90,15 @@ selectGitPack gh = do
    <&> listToMaybe . fmap fromOnly
 
 
+insertCBlock :: MonadIO m => GitHash -> HashRef -> DBPipeM m ()
+insertCBlock co cblk = do
+  insert [qc|
+    insert into cblock (kommit, cblock) values(?,?)
+    on conflict (kommit) do update set cblock = excluded.cblock
+         |] (co, cblk)
+
+selectCBlock :: MonadIO m => GitHash -> DBPipeM m (Maybe HashRef)
+selectCBlock gh = do
+  select [qc|select cblock from cblock where kommit = ? limit 1|] (Only gh)
+   <&> listToMaybe . fmap fromOnly
+