diff --git a/lib/codecs/array_to_array.ml b/lib/codecs/array_to_array.ml
index 8de6b960..0dfe6887 100644
--- a/lib/codecs/array_to_array.ml
+++ b/lib/codecs/array_to_array.ml
@@ -1,10 +1,9 @@
 module Ndarray = Owl.Dense.Ndarray.Generic
 
-type dimension_order = int array [@@deriving show]
+type dimension_order = int array
 
 type array_to_array =
   | Transpose of dimension_order
-  [@@deriving show]
 
 type error =
   [ `Transpose_order of dimension_order * string ]
diff --git a/lib/codecs/array_to_array.mli b/lib/codecs/array_to_array.mli
index fcdb5871..a80817e4 100644
--- a/lib/codecs/array_to_array.mli
+++ b/lib/codecs/array_to_array.mli
@@ -8,9 +8,6 @@ type array_to_array =
 type error =
   [ `Transpose_order of dimension_order * string ]
 
-val pp_array_to_array : Format.formatter -> array_to_array -> unit
-val show_array_to_array : array_to_array -> string
-
 module ArrayToArray : sig 
   val parse
     : ('a, 'b) Util.array_repr ->
diff --git a/lib/codecs/array_to_bytes.ml b/lib/codecs/array_to_bytes.ml
index ca9192ee..27d4c286 100644
--- a/lib/codecs/array_to_bytes.ml
+++ b/lib/codecs/array_to_bytes.ml
@@ -7,17 +7,14 @@ module Ndarray = Owl.Dense.Ndarray.Generic
 type endianness =
   | Little
   | Big
-  [@@deriving show]
 
 type loc =
   | Start
   | End
-  [@@deriving show]
 
 type array_to_bytes =
   | Bytes of endianness
   | ShardingIndexed of shard_config
-  [@@deriving show]
 
 and shard_config =
   {chunk_shape : int array
@@ -29,7 +26,6 @@ and chain =
   {a2a: array_to_array list
   ;a2b: array_to_bytes
   ;b2b: bytes_to_bytes list}
-  [@@deriving show]
 
 type error =
   [ Extensions.error
diff --git a/lib/codecs/array_to_bytes.mli b/lib/codecs/array_to_bytes.mli
index 8a854583..30368cd1 100644
--- a/lib/codecs/array_to_bytes.mli
+++ b/lib/codecs/array_to_bytes.mli
@@ -20,9 +20,6 @@ and chain = {
   b2b: Bytes_to_bytes.bytes_to_bytes list;
 }
 
-val pp_chain : Format.formatter -> chain -> unit
-val show_chain : chain -> string
-
 type error =
   [ Extensions.error
   | Array_to_array.error
diff --git a/lib/codecs/bytes_to_bytes.ml b/lib/codecs/bytes_to_bytes.ml
index 83bd5e15..05bc440a 100644
--- a/lib/codecs/bytes_to_bytes.ml
+++ b/lib/codecs/bytes_to_bytes.ml
@@ -2,12 +2,10 @@ module Ndarray = Owl.Dense.Ndarray.Generic
 
 type compression_level =
   | L0 | L1 | L2 | L3 | L4 | L5 | L6 | L7 | L8 | L9
-  [@@deriving show]
 
 type bytes_to_bytes =
   | Crc32c
   | Gzip of compression_level
-  [@@deriving show]
 
 type error = 
   [ `Gzip of Ezgzip.error ]
diff --git a/lib/codecs/bytes_to_bytes.mli b/lib/codecs/bytes_to_bytes.mli
index bb9e5683..fa5a0f54 100644
--- a/lib/codecs/bytes_to_bytes.mli
+++ b/lib/codecs/bytes_to_bytes.mli
@@ -10,9 +10,6 @@ type bytes_to_bytes =
 type error = 
   [ `Gzip of Ezgzip.error ]
 
-val pp_bytes_to_bytes : Format.formatter -> bytes_to_bytes -> unit
-val show_bytes_to_bytes : bytes_to_bytes -> string
-
 module BytesToBytes : sig
   val compute_encoded_size : int -> bytes_to_bytes -> int
   val encode : bytes_to_bytes -> string -> (string, [> error]) result
diff --git a/lib/codecs/codecs.ml b/lib/codecs/codecs.ml
index 9679c21b..1b023817 100644
--- a/lib/codecs/codecs.ml
+++ b/lib/codecs/codecs.ml
@@ -77,10 +77,6 @@ and variable_to_internal_b2b b2b =
 module Chain = struct
   type t = chain
 
-  let pp = pp_chain
-
-  let show = show_chain
-
   let create : 
     type a b. (a, b) Util.array_repr -> codec_chain -> (t, [> error ]) result
     = fun repr cc ->
diff --git a/lib/codecs/codecs.mli b/lib/codecs/codecs.mli
index 5d138046..134806cc 100644
--- a/lib/codecs/codecs.mli
+++ b/lib/codecs/codecs.mli
@@ -39,34 +39,31 @@ type codec_chain = {
   b2b: bytestobytes list;
 }
 
-type error = Array_to_bytes.error
+type error =
+  [ `Extension of string 
+  | `Gzip of Ezgzip.error
+  | `Transpose_order of int array * string
+  | `Sharding of int array * int array * string ]
 
 module Chain : sig
   type t
 
-  val create
-    : ('a, 'b) Util.array_repr -> codec_chain -> (t, [> error]) result
+  val create :
+    ('a, 'b) Util.array_repr -> codec_chain -> (t, [> error ]) result
 
   val default : t
 
   val compute_encoded_size : int -> t -> int
 
-  val encode
-    : t -> ('a, 'b) Ndarray.t -> (string, [> error]) result
+  val encode :
+    t -> ('a, 'b) Ndarray.t -> (string, [> error ]) result
 
-  val decode
-    : t ->
-      ('a, 'b) Util.array_repr ->
-      string ->
-      (('a, 'b) Ndarray.t, [> error]) result
+  val decode :
+    t -> ('a, 'b) Util.array_repr -> string -> (('a, 'b) Ndarray.t, [> error]) result
 
   val ( = ) : t -> t -> bool
 
   val of_yojson : Yojson.Safe.t -> (t, string) result
 
   val to_yojson : t -> Yojson.Safe.t
-
-  val pp : Format.formatter -> t -> unit
-
-  val show : t -> string
 end
diff --git a/test/test_codecs.ml b/test/test_codecs.ml
index b03a7855..c853d194 100644
--- a/test/test_codecs.ml
+++ b/test/test_codecs.ml
@@ -114,8 +114,7 @@ let tests = [
 
   let str = Chain.to_yojson c |> Yojson.Safe.to_string in
   (match Chain.of_yojson @@ Yojson.Safe.from_string str with
-  | Ok v ->
-    assert_equal ~printer:Chain.show v c;
+  | Ok v -> assert_equal v c;
   | Error _ ->
     assert_failure
       "a serialized chain should successfully deserialize"))
diff --git a/test/test_metadata.ml b/test/test_metadata.ml
index e1d6dfc8..dba075b8 100644
--- a/test/test_metadata.ml
+++ b/test/test_metadata.ml
@@ -80,7 +80,6 @@ let test_array_metadata
     ~printer:show_int_array shape @@ ArrayMetadata.shape meta;
 
   assert_equal
-    ~printer:Codecs.Chain.show
     Codecs.Chain.default @@
     ArrayMetadata.codecs meta;