diff --git a/git-kv.opam b/git-kv.opam
index 14f7b5e..a239187 100644
--- a/git-kv.opam
+++ b/git-kv.opam
@@ -18,3 +18,7 @@ build: [
   ["dune" "subst"] {dev}
   ["dune" "build" "-p" name "-j" jobs]
 ]
+
+pin-depends: [
+  [ "carton.dev" "git+https://github.com/mirage/ocaml-git.git#8cb31ed46aa2600f645dba204b164c7fce2f7037" ]
+]
diff --git a/src/git_kv.ml b/src/git_kv.ml
index a6dba20..6563ec9 100644
--- a/src/git_kv.ml
+++ b/src/git_kv.ml
@@ -178,6 +178,11 @@ module Delta = Carton_lwt.Enc.Delta (SHA1) (Verbose)
 module First_pass = Carton.Dec.Fp (SHA1)
 module Verify = Carton.Dec.Verify (SHA1) (Scheduler) (Lwt_scheduler)
 
+let ( <.> ) f g = fun x -> f (g x)
+let ( >>? ) x f = let open Lwt.Infix in match x with
+  | Some x -> f x >>= fun v -> Lwt.return_some v
+  | None -> Lwt.return_none
+
 let pack t ~commit stream =
   let open Lwt.Infix in
   let load t hash =
@@ -216,24 +221,29 @@ let pack t ~commit stream =
   ctx := SHA1.feed_bigstring !ctx header ~off:0 ~len:12 ;
   cursor := Int64.add !cursor 12L ;
   let encode_target idx =
-    Hashtbl.add offsets (Carton.Enc.target_uid targets.(idx)) !cursor ;
-    Carton_lwt.Enc.encode_target ~b ~find ~load:(load t) ~uid targets.(idx) ~cursor:(Int64.to_int !cursor)
-    >>= fun (len, encoder) ->
-    let payload = Bigstringaf.substring b.o ~off:0 ~len in
-    stream (Some payload) ;
-    ctx := SHA1.feed_bigstring !ctx b.o ~off:0 ~len ;
-    cursor := Int64.add !cursor (Int64.of_int len) ;
-    let rec go encoder = match Carton.Enc.N.encode ~o:b.o encoder with
-      | `Flush (encoder, len) ->
-        let payload = Bigstringaf.substring b.o ~off:0 ~len in
-        stream (Some payload) ;
-        ctx := SHA1.feed_bigstring !ctx b.o ~off:0 ~len ;
-        cursor := Int64.add !cursor (Int64.of_int len) ;
-        let encoder = Carton.Enc.N.dst encoder b.o 0 (Bigstringaf.length b.o) in
-        go encoder
-      | `End -> Lwt.return_unit in
-    let encoder = Carton.Enc.N.dst encoder b.o 0 (Bigstringaf.length b.o) in
-    go encoder in
+    Carton.Enc.target_patch targets.(idx)
+    >>? (find <.> Carton.Enc.source_of_patch)
+    >>= function
+    | Some None -> failwith "Try to encode an OBJ_REF object" (* XXX(dinosaure): should never occur! *)
+    | Some (Some (_ (* offset *) : int)) | None ->
+      Hashtbl.add offsets (Carton.Enc.target_uid targets.(idx)) !cursor ;
+      Carton_lwt.Enc.encode_target ~b ~find ~load:(load t) ~uid targets.(idx) ~cursor:(Int64.to_int !cursor)
+      >>= fun (len, encoder) ->
+      let payload = Bigstringaf.substring b.o ~off:0 ~len in
+      stream (Some payload) ;
+      ctx := SHA1.feed_bigstring !ctx b.o ~off:0 ~len ;
+      cursor := Int64.add !cursor (Int64.of_int len) ;
+      let rec go encoder = match Carton.Enc.N.encode ~o:b.o encoder with
+        | `Flush (encoder, len) ->
+          let payload = Bigstringaf.substring b.o ~off:0 ~len in
+          stream (Some payload) ;
+          ctx := SHA1.feed_bigstring !ctx b.o ~off:0 ~len ;
+          cursor := Int64.add !cursor (Int64.of_int len) ;
+          let encoder = Carton.Enc.N.dst encoder b.o 0 (Bigstringaf.length b.o) in
+          go encoder
+        | `End -> Lwt.return_unit in
+      let encoder = Carton.Enc.N.dst encoder b.o 0 (Bigstringaf.length b.o) in
+      go encoder in
   let rec go idx =
     if idx < Array.length targets
     then encode_target idx >>= fun () -> go (succ idx)
@@ -253,129 +263,35 @@ let to_octets t = match t.head with
     pack t.store ~commit stream >|= fun () ->
     Buffer.contents buf
 
-let digest ~kind ?(off = 0) ?len buf =
-  let len =
-    match len with Some len -> len | None -> Bigstringaf.length buf - off in
-  let ctx = SHA1.empty in
-  let ctx =
-    match kind with
-    | `A -> SHA1.feed_string ctx (Fmt.str "commit %d\000" len)
-    | `B -> SHA1.feed_string ctx (Fmt.str "tree %d\000" len)
-    | `C -> SHA1.feed_string ctx (Fmt.str "blob %d\000" len)
-    | `D -> SHA1.feed_string ctx (Fmt.str "tag %d\000" len) in
-  let ctx = SHA1.feed_bigstring ctx ~off ~len buf in
-  SHA1.get ctx
-
-let analyze stream =
-  let where = Hashtbl.create 0x100 in
-  let child = Hashtbl.create 0x100 in
-  let sizes = Hashtbl.create 0x100 in
-
-  let replace tbl k v = match Hashtbl.find_opt tbl k with
-    | Some v' -> if v' < v then Hashtbl.replace tbl k v
-    | _ -> Hashtbl.add tbl k v in
-
-  let rec go acc tmp decoder = let open Lwt.Infix in
-    match First_pass.decode decoder with
-    | `Await decoder ->
-      ( stream () >>= function
-      | Some str ->
-        let tmp = Bigstringaf.of_string str ~off:0 ~len:(String.length str) in
-        go acc tmp (First_pass.src decoder tmp 0 (String.length str))
-      | None -> failwith "Truncated PACK file" )
-    | `Peek decoder ->
-      let keep = First_pass.src_rem decoder in
-      ( stream () >>= function
-      | Some str ->
-        let tmp = Bigstringaf.create (keep + String.length str) in
-        Bigstringaf.blit tmp ~src_off:0 tmp ~dst_off:0 ~len:keep ;
-        Bigstringaf.blit_from_string str ~src_off:0 tmp ~dst_off:keep 
-          ~len:(String.length str) ;
-        go acc tmp (First_pass.src decoder tmp 0 (keep + String.length str))
-      | None -> failwith "Truncated PACK file" )
-    | `Entry ({ First_pass.kind= Base _; offset; size; _ }, decoder) ->
-      Hashtbl.add where offset (First_pass.count decoder - 1) ;
-      Hashtbl.add sizes offset size ;
-      go (Verify.unresolved_base ~cursor:offset :: acc) tmp decoder
-    | `Entry ({ First_pass.kind= Ofs { sub= v; source; target; }
-              ; offset; _ }, decoder) ->
-      Hashtbl.add where offset (First_pass.count decoder - 1) ;
-      replace sizes Int64.(sub offset (of_int v)) source ;
-      replace sizes offset target ;
-      ( try let vs = Hashtbl.find child (`Ofs Int64.(sub offset (of_int v))) in
-            Hashtbl.replace child (`Ofs Int64.(sub offset (of_int v))) (offset :: vs)
-        with _ -> Hashtbl.add child (`Ofs Int64.(sub offset (of_int v))) [ offset ] ) ;
-      go (Verify.unresolved_node :: acc) tmp decoder
-    | `Entry ({ First_pass.kind= Ref { ptr; target; source; }
-              ; offset; _ }, decoder) ->
-      Hashtbl.add where offset (First_pass.count decoder - 1) ;
-      replace sizes offset (Stdlib.max target source) ;
-      ( try let vs = Hashtbl.find child (`Ref ptr) in
-            Hashtbl.replace child (`Ref ptr) (offset :: vs)
-        with _ -> Hashtbl.add child (`Ref ptr) [ offset ] ) ;
-      go (Verify.unresolved_node :: acc) tmp decoder
-    | `End _hash ->
-      let where ~cursor = Hashtbl.find where cursor in
-      let children ~cursor ~uid =
-        match Hashtbl.find_opt child (`Ofs cursor),
-              Hashtbl.find_opt child (`Ref uid) with
-        | Some a, Some b -> List.sort_uniq compare (a @ b)
-        | Some x, None | None, Some x -> x
-        | None, None -> [] in
-      let weight ~cursor = Hashtbl.find sizes cursor in
-      let oracle = { Carton.Dec.where
-                   ; Carton.Dec.children
-                   ; Carton.Dec.digest
-                   ; Carton.Dec.weight } in
-      Lwt.return (List.rev acc, oracle)
-    | `Malformed err -> failwith err in
-
-  let o = Bigstringaf.create De.io_buffer_size in
-  let allocate _ = De.make_window ~bits:15 in
-  let decoder = First_pass.decoder ~o ~allocate `Manual in
-  let open Lwt.Infix in
-  go [] De.bigstring_empty decoder >>= fun (matrix, oracle) ->
-  Lwt.return (Array.of_list matrix, oracle)
-
-let stream_of_string str =
-  let closed = ref false in
-  fun () -> match !closed with
-  | true -> Lwt.return_none
-  | false -> closed := true ; Lwt.return_some str
+(* XXX(dinosaure): we have the full-control between [to_octets]/[of_octets]
+   and we are currently not able to generate a PACK file with OBJ_REF objects.
+   That mostly means that only one pass is enough to extract all objects!
+   OBJ_OFS objects need only already consumed objects. *)
 
 let map contents ~pos len =
   let off = Int64.to_int pos in
-  let len = min (String.length contents - off) len in
-  Bigstringaf.of_string ~off:(Int64.to_int pos) ~len contents
+  let len = min (Bigstringaf.length contents - off) len in
+  Bigstringaf.sub ~off:(Int64.to_int pos) ~len contents
 
-let unpack contents =
-  let open Lwt.Infix in
-  analyze (stream_of_string contents) >>= fun (matrix, oracle) ->
-  let z = De.bigstring_create De.io_buffer_size in
+let analyze store contents =
+  let len = String.length contents in
+  let contents = Bigstringaf.of_string contents ~off:0 ~len in
   let allocate bits = De.make_window ~bits in
   let never _ = assert false in
-  let pack = Carton.Dec.make contents ~allocate ~z ~uid_ln:SHA1.length
-    ~uid_rw:SHA1.of_raw_string never in
-  Verify.verify ~threads:4 pack ~map ~oracle ~verbose:ignore ~matrix >>= fun () ->
-  let index = Hashtbl.create (Array.length matrix) in
-  let iter v =
-    let offset = Verify.offset_of_status v in
-    let hash = Verify.uid_of_status v in
-    Hashtbl.add index hash offset in
-  Array.iter iter matrix ;
-  let pack =
-    Carton.Dec.make contents ~allocate ~z ~uid_ln:SHA1.length
-      ~uid_rw:SHA1.of_raw_string (Hashtbl.find index) in
-  init_store ()
-  >|= Rresult.R.reword_error (Rresult.R.msgf "%a" Store.pp_error)
-  >|= Rresult.R.failwith_error_msg >>= fun store ->
-  let rec go commit idx =
-    if idx < Array.length matrix
-    then
-      let cursor = Verify.offset_of_status matrix.(idx) in
+  let pack = Carton.Dec.make contents ~allocate
+    ~z:(De.bigstring_create De.io_buffer_size)
+    ~uid_ln:SHA1.length ~uid_rw:SHA1.of_raw_string never in
+  let objects = Hashtbl.create 0x100 in
+
+  let rec go head decoder = let open Lwt.Infix in
+    match First_pass.decode decoder with
+    | `Await _decoder
+    | `Peek _decoder -> failwith "Truncated PACK file"
+    | `Entry ({ First_pass.kind= Base _; offset= cursor; _ }, decoder) ->
       let weight = Carton.Dec.weight_of_offset ~map pack ~weight:Carton.Dec.null cursor in
       let raw = Carton.Dec.make_raw ~weight in
       let v = Carton.Dec.of_offset ~map pack raw ~cursor in
+      Hashtbl.add objects cursor v ;
       let kind = match Carton.Dec.kind v with
         | `A -> `Commit
         | `B -> `Tree
@@ -383,19 +299,42 @@ let unpack contents =
         | `D -> `Tag in
       Store.write_inflated store ~kind
         (Cstruct.of_bigarray ~off:0 ~len:(Carton.Dec.len v) (Carton.Dec.raw v)) >>= fun hash ->
-      ( if kind = `Commit
-        then Store.shallow store hash
-        else Lwt.return_unit ) >>= fun () ->
-      go (if kind = `Commit then Some hash else None) (succ idx)
-    else Lwt.return commit in
-  go None 0 >>= fun head -> Lwt.return (store, head)
+      ( match kind with
+      | `Commit -> go (Some hash) decoder
+      | _ -> go head decoder )
+    | `Entry ({ First_pass.kind= Ofs { sub= s; _ } ; offset= cursor; _ }, decoder) ->
+      let weight = Carton.Dec.weight_of_offset ~map pack ~weight:Carton.Dec.null cursor in
+      let source = Int64.sub cursor (Int64.of_int s) in
+      let v = Carton.Dec.copy ~flip:true ~weight (Hashtbl.find objects source) (* XXX(dinosaure): should never fail *) in
+      let v = Carton.Dec.of_offset_with_source ~map pack v ~cursor in
+      Hashtbl.add objects cursor v ;
+      let kind = match Carton.Dec.kind v with
+        | `A -> `Commit
+        | `B -> `Tree
+        | `C -> `Blob
+        | `D -> `Tag in
+      Store.write_inflated store ~kind
+        (Cstruct.of_bigarray ~off:0 ~len:(Carton.Dec.len v) (Carton.Dec.raw v)) >>= fun hash ->
+      ( match kind with
+      | `Commit -> go (Some hash) decoder
+      | _ -> go head decoder )
+    | `Entry ({ First_pass.kind= Ref _; _ }, _decoder) ->
+      failwith "Invalid PACK file (OBJ_REF)"
+    | `End _hash -> Lwt.return head
+    | `Malformed err -> failwith err in
+  let decoder = First_pass.decoder ~o:(Bigstringaf.create De.io_buffer_size) ~allocate `Manual in
+  let decoder = First_pass.src decoder contents 0 len in
+  go None decoder
 
 let of_octets ctx ~remote data =
-  (* TODO maybe recover edn and branch from data as well? *)
   let open Lwt.Infix in
+  (* TODO maybe recover edn and branch from data as well? *)
   Lwt.catch
     (fun () ->
-       unpack data >>= fun (store, head) ->
+       init_store ()
+       >|= Rresult.R.reword_error (Rresult.R.msgf "%a" Store.pp_error)
+       >|= Rresult.R.failwith_error_msg >>= fun store ->
+       analyze store data >>= fun head ->
        let edn, branch = split_url remote in
        Lwt.return_ok { ctx ; edn ; branch ; store ; head; })
     (fun exn ->