diff --git a/.gitlab/ci/opam-ci.yml b/.gitlab/ci/opam-ci.yml
index b860b7234d3b95d6c25eec5bf4385878cc6962c7..e452c570cf63bc447bd46658dac3d55ff90192f4 100644
--- a/.gitlab/ci/opam-ci.yml
+++ b/.gitlab/ci/opam-ci.yml
@@ -33,6 +33,8 @@
 
 # Ignoring package tezos-scoru-wasm-test, it only contains tests or private targets
 
+# Ignoring package tezos-scoru-wasm-test-helpers, it only contains tests or private targets
+
 # Ignoring package tezos-shell-context-test, it only contains tests or private targets
 
 # Ignoring package tezos-tps-evaluation, it only contains tests or private targets
diff --git a/dune-project b/dune-project
index c7ebb8021228e1397bdca0ca8ae27ad0400c196b..70f4f423dd9791ff2527e182014d8037589446a1 100644
--- a/dune-project
+++ b/dune-project
@@ -186,6 +186,7 @@
 (package (name tezos-sc-rollup-alpha))
 (package (name tezos-scoru-wasm))
 (package (name tezos-scoru-wasm-test)(allow_empty))
+(package (name tezos-scoru-wasm-test-helpers)(allow_empty))
 (package (name tezos-shell))
 (package (name tezos-shell-benchmarks))
 (package (name tezos-shell-context))
diff --git a/manifest/main.ml b/manifest/main.ml
index f73d8b1c975a84408edcec724e92fc663fe6f754..0ce9ec6f85b48778a0bb715874b6590d8d7a4f87 100644
--- a/manifest/main.ml
+++ b/manifest/main.ml
@@ -3142,6 +3142,28 @@ let octez_dal_node_lib =
         octez_protocol_updater |> open_;
       ]
 
+let octez_scoru_wasm_tests_helpers =
+  private_lib
+    "test_scoru_wasm_test_helpers"
+    ~path:"src/lib_scoru_wasm/test/helpers"
+    ~opam:"tezos-scoru-wasm-test-helpers"
+    ~synopsis:"helpers for testing for the scoru-wasm functionality"
+    ~deps:
+      [
+        octez_base |> open_ ~m:"TzPervasives";
+        tree_encoding;
+        octez_base_unix;
+        octez_context_disk;
+        octez_base_test_helpers |> open_;
+        octez_test_helpers;
+        octez_scoru_wasm;
+        qcheck_alcotest;
+        alcotest_lwt;
+        tezt_lib;
+        octez_webassembly_interpreter_extra |> open_;
+      ]
+    ~preprocess:[staged_pps [ppx_import; ppx_deriving_show]]
+
 let _octez_scoru_wasm_tests =
   test
     "test_scoru_wasm"
@@ -3160,6 +3182,7 @@ let _octez_scoru_wasm_tests =
         qcheck_alcotest;
         alcotest_lwt;
         tezt_lib;
+        octez_scoru_wasm_tests_helpers |> open_;
         octez_webassembly_interpreter_extra |> open_;
       ]
     ~preprocess:[staged_pps [ppx_import; ppx_deriving_show]]
@@ -3660,9 +3683,13 @@ end = struct
               main |> open_;
               test_helpers |> if_some |> open_;
               alcotest_lwt;
+              octez_scoru_wasm_tests_helpers |> if_ N.(number >= 016) |> open_;
               octez_stdlib |> if_ N.(number >= 013) |> open_;
               octez_crypto_dal |> if_ N.(number >= 016) |> open_;
               octez_scoru_wasm;
+              octez_webassembly_interpreter_extra
+              |> if_ N.(number >= 016)
+              |> open_;
             ]
           ~dune:
             Dune.
diff --git a/opam/tezos-protocol-alpha-tests.opam b/opam/tezos-protocol-alpha-tests.opam
index f92f66d77d145862aa1a99cd5306578e6fc6c32b..bab091fb319dee74602902acbe4a87d902f8ffac 100644
--- a/opam/tezos-protocol-alpha-tests.opam
+++ b/opam/tezos-protocol-alpha-tests.opam
@@ -30,8 +30,10 @@ depends: [
   "tezos-client-base" {with-test}
   "tezos-protocol-environment" {with-test}
   "tezos-stdlib-unix" {with-test}
+  "tezos-scoru-wasm-test-helpers" {with-test}
   "tezos-stdlib" {with-test}
   "tezos-scoru-wasm" {with-test}
+  "tezos-webassembly-interpreter-extra" {with-test}
   "tezt-tezos" {with-test}
 ]
 build: [
diff --git a/opam/tezos-scoru-wasm-test-helpers.opam b/opam/tezos-scoru-wasm-test-helpers.opam
new file mode 100644
index 0000000000000000000000000000000000000000..8452670e9fbb54bcb2b4c2cce3a4a6f03f0459e1
--- /dev/null
+++ b/opam/tezos-scoru-wasm-test-helpers.opam
@@ -0,0 +1,30 @@
+# This file was automatically generated, do not edit.
+# Edit file manifest/main.ml instead.
+opam-version: "2.0"
+maintainer: "contact@tezos.com"
+authors: ["Tezos devteam"]
+homepage: "https://www.tezos.com/"
+bug-reports: "https://gitlab.com/tezos/tezos/issues"
+dev-repo: "git+https://gitlab.com/tezos/tezos.git"
+license: "MIT"
+depends: [
+  "dune" { >= "3.0" }
+  "ppx_import"
+  "ppx_deriving"
+  "tezos-base"
+  "tezos-tree-encoding"
+  "tezos-context"
+  "tezos-base-test-helpers"
+  "tezos-test-helpers"
+  "tezos-scoru-wasm"
+  "qcheck-alcotest" { >= "0.18" }
+  "alcotest-lwt" { >= "1.5.0" }
+  "tezt"
+  "tezos-webassembly-interpreter-extra"
+]
+build: [
+  ["rm" "-r" "vendors"]
+  ["dune" "build" "-p" name "-j" jobs]
+  ["dune" "runtest" "-p" name "-j" jobs] {with-test}
+]
+synopsis: "helpers for testing for the scoru-wasm functionality"
diff --git a/opam/tezos-scoru-wasm-test.opam b/opam/tezos-scoru-wasm-test.opam
index cbc156f07753fa291c4578db51799b41b149a4ad..a810c23f7a0e2d2ade5ab907606c79affc3e6e97 100644
--- a/opam/tezos-scoru-wasm-test.opam
+++ b/opam/tezos-scoru-wasm-test.opam
@@ -20,6 +20,7 @@ depends: [
   "qcheck-alcotest" { with-test & >= "0.18" }
   "alcotest-lwt" { with-test & >= "1.5.0" }
   "tezt" {with-test}
+  "tezos-scoru-wasm-test-helpers" {with-test}
   "tezos-webassembly-interpreter-extra" {with-test}
 ]
 build: [
diff --git a/src/lib_scoru_wasm/test/dune b/src/lib_scoru_wasm/test/dune
index 84cd43c8581a7448309f86cfd934081fdc6b7e36..31242561c34aea2007bcab078a7c44ffa6e8bc92 100644
--- a/src/lib_scoru_wasm/test/dune
+++ b/src/lib_scoru_wasm/test/dune
@@ -14,12 +14,14 @@
   qcheck-alcotest
   alcotest-lwt
   tezt
+  test_scoru_wasm_test_helpers
   tezos-webassembly-interpreter-extra)
  (preprocess (staged_pps ppx_import ppx_deriving.show))
  (flags
   (:standard)
   -open Tezos_base.TzPervasives
   -open Tezos_base_test_helpers
+  -open Test_scoru_wasm_test_helpers
   -open Tezos_webassembly_interpreter_extra))
 
 (rule
diff --git a/src/lib_scoru_wasm/test/ast_generators.ml b/src/lib_scoru_wasm/test/helpers/ast_generators.ml
similarity index 100%
rename from src/lib_scoru_wasm/test/ast_generators.ml
rename to src/lib_scoru_wasm/test/helpers/ast_generators.ml
diff --git a/src/lib_scoru_wasm/test/ast_printer.ml b/src/lib_scoru_wasm/test/helpers/ast_printer.ml
similarity index 100%
rename from src/lib_scoru_wasm/test/ast_printer.ml
rename to src/lib_scoru_wasm/test/helpers/ast_printer.ml
diff --git a/src/lib_scoru_wasm/test/helpers/dune b/src/lib_scoru_wasm/test/helpers/dune
new file mode 100644
index 0000000000000000000000000000000000000000..61d7cef1fd59cfb05c70a742be40fbb90a6cf01f
--- /dev/null
+++ b/src/lib_scoru_wasm/test/helpers/dune
@@ -0,0 +1,25 @@
+; This file was automatically generated, do not edit.
+; Edit file manifest/main.ml instead.
+
+(library
+ (name test_scoru_wasm_test_helpers)
+ (package tezos-scoru-wasm-test-helpers)
+ (instrumentation (backend bisect_ppx))
+ (libraries
+  tezos-base
+  tezos-tree-encoding
+  tezos-base.unix
+  tezos-context.disk
+  tezos-base-test-helpers
+  tezos-test-helpers
+  tezos-scoru-wasm
+  qcheck-alcotest
+  alcotest-lwt
+  tezt
+  tezos-webassembly-interpreter-extra)
+ (preprocess (staged_pps ppx_import ppx_deriving.show))
+ (flags
+  (:standard)
+  -open Tezos_base.TzPervasives
+  -open Tezos_base_test_helpers
+  -open Tezos_webassembly_interpreter_extra))
diff --git a/src/lib_scoru_wasm/test/test_encodings_util.ml b/src/lib_scoru_wasm/test/helpers/test_encodings_util.ml
similarity index 100%
rename from src/lib_scoru_wasm/test/test_encodings_util.ml
rename to src/lib_scoru_wasm/test/helpers/test_encodings_util.ml
diff --git a/src/lib_scoru_wasm/test/test_wasm_pvm_encodings.ml b/src/lib_scoru_wasm/test/helpers/test_wasm_pvm_encodings.ml
similarity index 100%
rename from src/lib_scoru_wasm/test/test_wasm_pvm_encodings.ml
rename to src/lib_scoru_wasm/test/helpers/test_wasm_pvm_encodings.ml
diff --git a/src/lib_scoru_wasm/test/wasm_utils.ml b/src/lib_scoru_wasm/test/helpers/wasm_utils.ml
similarity index 99%
rename from src/lib_scoru_wasm/test/wasm_utils.ml
rename to src/lib_scoru_wasm/test/helpers/wasm_utils.ml
index 6ff13bc9188a67aa25a703eda35bf67a78da204f..95532b047c68b98e0e5115c060a1ba65ed27a379 100644
--- a/src/lib_scoru_wasm/test/wasm_utils.ml
+++ b/src/lib_scoru_wasm/test/helpers/wasm_utils.ml
@@ -262,7 +262,7 @@ let test_with_kernel kernel (test : string -> (unit, _) result Lwt.t) () =
   (* Reading files using `Tezt_lib` can be fragile and not future-proof, see
      issue https://gitlab.com/tezos/tezos/-/issues/3746. *)
   let kernel_file =
-    project_root // Filename.dirname __FILE__ // "wasm_kernels"
+    project_root // Filename.dirname __FILE__ // "../wasm_kernels"
     // (kernel ^ ".wasm")
   in
   let* () =
diff --git a/src/lib_scoru_wasm/wasm_pvm.ml b/src/lib_scoru_wasm/wasm_pvm.ml
index 883c1c296d1b5895936151d21b714de70862c73e..b3f6fc2b39f056d087b067272ad5fc9d622cf078 100644
--- a/src/lib_scoru_wasm/wasm_pvm.ml
+++ b/src/lib_scoru_wasm/wasm_pvm.ml
@@ -723,6 +723,16 @@ module Make (T : Tezos_tree_encoding.TREE) :
           {pvm_state with reboot_counter = pvm_state.maximum_reboots_per_input}
         in
         Tree_encoding_runner.encode pvm_state_encoding pvm_state tree
+
+      let get_output_buffer tree =
+        let open Lwt.Syntax in
+        let+ pvm = Tree_encoding_runner.decode pvm_state_encoding tree in
+        pvm.buffers.output
+
+      let get_input_buffer tree =
+        let open Lwt.Syntax in
+        let+ pvm = Tree_encoding_runner.decode pvm_state_encoding tree in
+        pvm.buffers.input
     end
   end
 
diff --git a/src/lib_scoru_wasm/wasm_pvm_sig.ml b/src/lib_scoru_wasm/wasm_pvm_sig.ml
index a58de1e57401745cc125d5f139369652cdf38615..a29cc3bfafade1c2ceb33fa22528c59ecffd91a2 100644
--- a/src/lib_scoru_wasm/wasm_pvm_sig.ml
+++ b/src/lib_scoru_wasm/wasm_pvm_sig.ml
@@ -89,6 +89,12 @@ module type Internal_for_tests = sig
   val set_maximum_reboots_per_input : Z.t -> tree -> tree Lwt.t
 
   val reset_reboot_counter : tree -> tree Lwt.t
+
+  val get_input_buffer :
+    tree -> Tezos_webassembly_interpreter.Input_buffer.t Lwt.t
+
+  val get_output_buffer :
+    tree -> Tezos_webassembly_interpreter.Output_buffer.t Lwt.t
 end
 
 (** This module type defines a WASM VM API used for smart-contract rollups. *)
diff --git a/src/proto_alpha/lib_protocol/test/unit/dune b/src/proto_alpha/lib_protocol/test/unit/dune
index cc9f541a60600a32f4f52b49131223e52e28e6f1..25103a12fff8c513deaaa8f6b77393ad0b68514b 100644
--- a/src/proto_alpha/lib_protocol/test/unit/dune
+++ b/src/proto_alpha/lib_protocol/test/unit/dune
@@ -15,9 +15,11 @@
   tezos-protocol-alpha
   tezos-alpha-test-helpers
   alcotest-lwt
+  test_scoru_wasm_test_helpers
   tezos-stdlib
   tezos-crypto-dal
-  tezos-scoru-wasm)
+  tezos-scoru-wasm
+  tezos-webassembly-interpreter-extra)
  (flags
   (:standard)
   -open Tezos_base.TzPervasives
@@ -27,8 +29,10 @@
   -open Tezos_client_alpha
   -open Tezos_protocol_alpha
   -open Tezos_alpha_test_helpers
+  -open Test_scoru_wasm_test_helpers
   -open Tezos_stdlib
-  -open Tezos_crypto_dal))
+  -open Tezos_crypto_dal
+  -open Tezos_webassembly_interpreter_extra))
 
 (rule
  (alias runtest)
diff --git a/src/proto_alpha/lib_protocol/test/unit/test_sc_rollup_wasm.ml b/src/proto_alpha/lib_protocol/test/unit/test_sc_rollup_wasm.ml
index 7fc39d919daa7c6dc86ba53d2da4f2104023ae63..b47364aa4e9d3534dfec49466c8064fe02a39eb2 100644
--- a/src/proto_alpha/lib_protocol/test/unit/test_sc_rollup_wasm.ml
+++ b/src/proto_alpha/lib_protocol/test/unit/test_sc_rollup_wasm.ml
@@ -34,6 +34,60 @@
 *)
 
 open Protocol
+open Tezos_micheline.Micheline
+open Michelson_v1_primitives
+open Tezos_webassembly_interpreter
+module Context = Tezos_context_memory.Context_binary
+open Tezos_scoru_wasm
+open Wasm_utils
+
+module Proof_encoding =
+  Tezos_context_merkle_proof_encoding.Merkle_proof_encoding
+
+module Wasm_context = struct
+  module Tree = struct
+    include Context.Tree
+
+    type tree = Context.tree
+
+    type t = Context.t
+
+    type key = string list
+
+    type value = bytes
+  end
+
+  type tree = Context.tree
+
+  type proof = Context.Proof.tree Context.Proof.t
+
+  let verify_proof p f =
+    Lwt.map Result.to_option (Context.verify_tree_proof p f)
+
+  let produce_proof context tree step =
+    let open Lwt_syntax in
+    let* context = Context.add_tree context [] tree in
+    let* _hash = Context.commit ~time:Time.Protocol.epoch context in
+    let index = Context.index context in
+    match Context.Tree.kinded_key tree with
+    | Some k ->
+        let* p = Context.produce_tree_proof index k step in
+        return (Some p)
+    | None -> return None
+
+  let kinded_hash_to_state_hash = function
+    | `Value hash | `Node hash ->
+        Sc_rollup_repr.State_hash.context_hash_to_state_hash hash
+
+  let proof_before proof = kinded_hash_to_state_hash proof.Context.Proof.before
+
+  let proof_after proof = kinded_hash_to_state_hash proof.Context.Proof.after
+
+  let proof_encoding = Proof_encoding.V2.Tree32.tree_proof_encoding
+end
+
+module Full_Wasm =
+  Sc_rollup_wasm.V2_0_0.Make (Environment.Wasm_2_0_0.Make) (Wasm_context)
 
 let test_initial_state_hash_wasm_pvm () =
   let open Alpha_context in
@@ -85,6 +139,131 @@ let test_metadata_size () =
     = Tezos_scoru_wasm.Host_funcs.Internal_for_tests.metadata_size) ;
   Lwt_result_syntax.return_unit
 
+let make_transaction value text contract =
+  let entrypoint = Entrypoint_repr.default in
+  let destination : Contract_hash.t =
+    Contract_hash.of_bytes_exn @@ Bytes.of_string contract
+  in
+  let unparsed_parameters =
+    strip_locations
+    @@ Prim
+         ( 0,
+           I_TICKET,
+           [Prim (0, I_PAIR, [Int (0, Z.of_int32 value); String (1, text)], [])],
+           [] )
+  in
+  Sc_rollup_outbox_message_repr.{unparsed_parameters; entrypoint; destination}
+
+let make_transactions () =
+  let l =
+    QCheck2.Gen.(
+      generate1
+      @@ list_size
+           (return 3)
+           (triple (string_size @@ return 20) int32 (small_string ~gen:char)))
+  in
+  List.map (fun (contract, i, s) -> make_transaction i s contract) l
+
+(* This is simple "echo kernel"  it spits out whatever it receive. It uses the
+   [write_output] host function and so it is used to test this function. *)
+let test_output () =
+  let open Lwt_result_syntax in
+  let rtype_offset = 0 in
+  let level_offset = 20 in
+  let id_offset = 40 in
+  let dst = 60 in
+  let max_bytes = 3600 in
+  let modul =
+    Format.sprintf
+      {|
+        (module
+          (type (;0;) (func (param i32 i32 i32 i32 i32) (result i32)))
+          (type $t0 (func (param i32 i32) (result i32)))
+          (type $t3 (func (param i32 i32 i32 i32 i32) (result i32)))
+          (import "rollup_safe_core" "read_input" (func $read_input (type $t3)))
+          (import "rollup_safe_core" "write_output" (func $write_output (type $t0)))
+          (func (export "kernel_next")
+            (local $size i32)
+           (local.set $size (call $read_input (i32.const %d)
+                              (i32.const %d)
+                              (i32.const %d)
+                              (i32.const %d)
+                              (i32.const %d)))
+            (call $write_output (i32.const %d)
+                               (local.get $size))
+            drop)
+          (memory (;0;) 17)
+          (export "memory" (memory 0))
+          )
+
+    |}
+      rtype_offset
+      level_offset
+      id_offset
+      dst
+      max_bytes
+      dst
+  in
+  let*! dummy = Context.init "/tmp" in
+  let dummy_context = Context.empty dummy in
+  let*! (empty_tree : Wasm.tree) = Test_encodings_util.empty_tree () in
+  let parsed = Parse.string_to_module modul in
+  let parsed =
+    match parsed.it with Script.Textual m -> m | _ -> assert false
+  in
+  let*! code = Encode.encode parsed in
+  let boot_sector =
+    Data_encoding.Binary.to_string_exn
+      Gather_floppies.origination_message_encoding
+      (Gather_floppies.Complete_kernel (String.to_bytes code))
+  in
+  let*! tree =
+    Wasm.Internal_for_tests.initial_tree_from_boot_sector
+      ~empty_tree
+      boot_sector
+  in
+  let*! tree =
+    Wasm.Internal_for_tests.set_max_nb_ticks (Z.of_int64 50_000_000L) tree
+  in
+  let*! tree = eval_until_input_requested tree in
+  let transactions = make_transactions () in
+  let out =
+    Sc_rollup_outbox_message_repr.(Atomic_transaction_batch {transactions})
+  in
+  let string_input_message =
+    Data_encoding.Binary.to_string_exn
+      Sc_rollup_outbox_message_repr.encoding
+      out
+  in
+  let*! tree = set_input_step string_input_message 0 tree in
+  let*! final_tree = eval_until_input_requested tree in
+  let*! output = Wasm.Internal_for_tests.get_output_buffer final_tree in
+  let*! level, message_index =
+    Tezos_webassembly_interpreter.Output_buffer.get_id output
+  in
+  let*! bytes_output_message =
+    Tezos_webassembly_interpreter.Output_buffer.get output level message_index
+  in
+  assert (string_input_message = Bytes.to_string bytes_output_message) ;
+  let message =
+    Data_encoding.Binary.of_bytes_exn
+      Sc_rollup_outbox_message_repr.encoding
+      bytes_output_message
+  in
+  assert (message = out) ;
+  let*? outbox_level =
+    Environment.wrap_tzresult @@ Raw_level_repr.of_int32 level
+  in
+  let output = Sc_rollup_PVM_sig.{outbox_level; message_index; message} in
+
+  let*! pf = Full_Wasm.produce_output_proof dummy_context final_tree output in
+
+  match pf with
+  | Ok proof ->
+      let*! valid = Full_Wasm.verify_output_proof proof in
+      fail_unless valid (Exn (Failure "An output proof is not valid."))
+  | Error _ -> failwith "Error during proof generation"
+
 let tests =
   [
     Tztest.tztest
@@ -96,4 +275,5 @@ let tests =
       `Quick
       test_incomplete_kernel_chunk_limit;
     Tztest.tztest "size of a rollup metadata" `Quick test_metadata_size;
+    Tztest.tztest "test output proofs" `Quick test_output;
   ]