diff --git a/src/proto_alpha/lib_protocol/alpha_context.mli b/src/proto_alpha/lib_protocol/alpha_context.mli
index 2956d330962269a361f6a2d5f9d730eb51f1d651..3c7f194115b4fa4b376027fe985316169dfe8513 100644
--- a/src/proto_alpha/lib_protocol/alpha_context.mli
+++ b/src/proto_alpha/lib_protocol/alpha_context.mli
@@ -1475,31 +1475,29 @@ end
 module Contract : sig
   include BASIC_DATA
 
-  type contract = t
-
   val in_memory_size : t -> Cache_memory_helpers.sint
 
-  val rpc_arg : contract RPC_arg.arg
+  val rpc_arg : t RPC_arg.arg
 
-  val to_b58check : contract -> string
+  val to_b58check : t -> string
 
-  val of_b58check : string -> contract tzresult
+  val of_b58check : string -> t tzresult
 
-  val implicit_contract : public_key_hash -> contract
+  val implicit_contract : public_key_hash -> t
 
-  val is_implicit : contract -> public_key_hash option
+  val is_implicit : t -> public_key_hash option
 
-  val is_originated : contract -> Contract_hash.t option
+  val is_originated : t -> Contract_hash.t option
 
-  val exists : context -> contract -> bool tzresult Lwt.t
+  val exists : context -> t -> bool Lwt.t
 
-  val must_exist : context -> contract -> unit tzresult Lwt.t
+  val must_exist : context -> t -> unit tzresult Lwt.t
 
-  val allocated : context -> contract -> bool tzresult Lwt.t
+  val allocated : context -> t -> bool Lwt.t
 
-  val must_be_allocated : context -> contract -> unit tzresult Lwt.t
+  val must_be_allocated : context -> t -> unit tzresult Lwt.t
 
-  val list : context -> contract list Lwt.t
+  val list : context -> t list Lwt.t
 
   val get_manager_key :
     ?error:error -> context -> public_key_hash -> public_key tzresult Lwt.t
@@ -1511,29 +1509,27 @@ module Contract : sig
     context -> public_key_hash -> public_key -> context tzresult Lwt.t
 
   val get_script_code :
-    context -> contract -> (context * Script.lazy_expr option) tzresult Lwt.t
+    context -> t -> (context * Script.lazy_expr option) tzresult Lwt.t
 
-  val get_script :
-    context -> contract -> (context * Script.t option) tzresult Lwt.t
+  val get_script : context -> t -> (context * Script.t option) tzresult Lwt.t
 
   val get_storage :
-    context -> contract -> (context * Script.expr option) tzresult Lwt.t
+    context -> t -> (context * Script.expr option) tzresult Lwt.t
 
   val get_counter : context -> public_key_hash -> Z.t tzresult Lwt.t
 
-  val get_balance : context -> contract -> Tez.t tzresult Lwt.t
+  val get_balance : context -> t -> Tez.t tzresult Lwt.t
 
-  val get_balance_carbonated :
-    context -> contract -> (context * Tez.t) tzresult Lwt.t
+  val get_balance_carbonated : context -> t -> (context * Tez.t) tzresult Lwt.t
 
   val fresh_contract_from_current_nonce : context -> (context * t) tzresult
 
   val originated_from_current_nonce :
-    since:context -> until:context -> contract list tzresult Lwt.t
+    since:context -> until:context -> t list tzresult Lwt.t
 
-  val get_frozen_bonds : context -> contract -> Tez.t tzresult Lwt.t
+  val get_frozen_bonds : context -> t -> Tez.t tzresult Lwt.t
 
-  val get_balance_and_frozen_bonds : context -> contract -> Tez.t tzresult Lwt.t
+  val get_balance_and_frozen_bonds : context -> t -> Tez.t tzresult Lwt.t
 
   module Legacy_big_map_diff : sig
     type item = private
@@ -1558,7 +1554,7 @@ module Contract : sig
 
   val update_script_storage :
     context ->
-    contract ->
+    t ->
     Script.expr ->
     Lazy_storage.diffs option ->
     context tzresult Lwt.t
@@ -1579,7 +1575,7 @@ module Contract : sig
 
   module Internal_for_tests : sig
     (** see [Contract_repr.originated_contract] for documentation *)
-    val originated_contract : Origination_nonce.Internal_for_tests.t -> contract
+    val originated_contract : Origination_nonce.Internal_for_tests.t -> t
 
     val paid_storage_space : context -> t -> Z.t tzresult Lwt.t
   end
diff --git a/src/proto_alpha/lib_protocol/apply.ml b/src/proto_alpha/lib_protocol/apply.ml
index 63fa38d88d70a7c3e91baf5f99856bdf21973658..376b2310803425e7cc633d4cdf1c41f449c9a212 100644
--- a/src/proto_alpha/lib_protocol/apply.ml
+++ b/src/proto_alpha/lib_protocol/apply.ml
@@ -956,7 +956,7 @@ let apply_transaction ~ctxt ~parameter ~source ~contract ~amount ~entrypoint
       error_when Tez.(amount = zero) (Empty_transaction contract) >>?= fun () ->
       (* If the implicit contract is not yet allocated at this point then
          the next transfer of tokens will allocate it. *)
-      Contract.allocated ctxt contract >|=? not)
+      Contract.allocated ctxt contract >|= ok >|=? not)
   >>=? fun allocated_destination_contract ->
   Token.transfer ctxt (`Contract source) (`Contract contract) amount
   >>=? fun (ctxt, balance_updates) ->
diff --git a/src/proto_alpha/lib_protocol/apply_results.ml b/src/proto_alpha/lib_protocol/apply_results.ml
index 25885de8ee7c824194f268be20bf5eae40f05c6d..a2146f53b400bad35ec55c564eb3b5bbd3246dcb 100644
--- a/src/proto_alpha/lib_protocol/apply_results.ml
+++ b/src/proto_alpha/lib_protocol/apply_results.ml
@@ -65,7 +65,7 @@ type packed_internal_manager_operation =
       -> packed_internal_manager_operation
 
 type 'kind internal_contents = {
-  source : Contract.contract;
+  source : Contract.t;
   operation : 'kind internal_manager_operation;
   nonce : int;
 }
diff --git a/src/proto_alpha/lib_protocol/apply_results.mli b/src/proto_alpha/lib_protocol/apply_results.mli
index 5b527e8a48178385f8e55e6a367c67dcc93f5369..a767d584d985b18c79d634bb285715036b462a24 100644
--- a/src/proto_alpha/lib_protocol/apply_results.mli
+++ b/src/proto_alpha/lib_protocol/apply_results.mli
@@ -52,7 +52,7 @@ val manager_operation_of_internal_operation :
   'kind internal_manager_operation -> 'kind Alpha_context.manager_operation
 
 type 'kind internal_contents = {
-  source : Contract.contract;
+  source : Contract.t;
   operation : 'kind internal_manager_operation;
   nonce : int;
 }
diff --git a/src/proto_alpha/lib_protocol/contract_repr.ml b/src/proto_alpha/lib_protocol/contract_repr.ml
index 5b57f87e18449d0db7dbdb453c55eeae6988c471..d6ddf1baefb0b781768f1c5bb8e9757bee22cc74 100644
--- a/src/proto_alpha/lib_protocol/contract_repr.ml
+++ b/src/proto_alpha/lib_protocol/contract_repr.ml
@@ -39,8 +39,6 @@ include Compare.Make (struct
     | (Originated _, Implicit _) -> 1
 end)
 
-type contract = t
-
 let blake2b_hash_size =
   let open Cache_memory_helpers in
   h1w +! string_size_gen 20
@@ -173,7 +171,7 @@ let rpc_arg =
     ()
 
 module Index = struct
-  type t = contract
+  type nonrec t = t
 
   let path_length = 1
 
diff --git a/src/proto_alpha/lib_protocol/contract_repr.mli b/src/proto_alpha/lib_protocol/contract_repr.mli
index 9c81fcbef6697e44d985d4f79ec657b8768b1596..ce6a926729fb6c84cd76d0b052f8ff39b79b4459 100644
--- a/src/proto_alpha/lib_protocol/contract_repr.mli
+++ b/src/proto_alpha/lib_protocol/contract_repr.mli
@@ -42,57 +42,54 @@ type t = private
   | Implicit of Signature.Public_key_hash.t
   | Originated of Contract_hash.t
 
-type contract = t
-
-include Compare.S with type t := contract
+include Compare.S with type t := t
 
 val in_memory_size : t -> Cache_memory_helpers.sint
 
 (** {2 Implicit contracts} *)
 
-val implicit_contract : Signature.Public_key_hash.t -> contract
+val implicit_contract : Signature.Public_key_hash.t -> t
 
-val is_implicit : contract -> Signature.Public_key_hash.t option
+val is_implicit : t -> Signature.Public_key_hash.t option
 
 (** {2 Originated contracts} *)
 
 (** [originated_contract nonce] is the contract address originated from [nonce].
 *)
-val originated_contract : Origination_nonce.t -> contract
+val originated_contract : Origination_nonce.t -> t
 
 (** [originated_contracts ~since ~until] is the contract addresses originated
     from [since] until [until]. The operation hash of nonce [since] and [until]
     must be the same or it will fail with an [assert]. [since] < [until] or the
     returned list is empty *)
 val originated_contracts :
-  since:Origination_nonce.t -> until:Origination_nonce.t -> contract list
+  since:Origination_nonce.t -> until:Origination_nonce.t -> t list
 
-val is_originated : contract -> Contract_hash.t option
+val is_originated : t -> Contract_hash.t option
 
 (** {2 Human readable notation} *)
 
 type error += Invalid_contract_notation of string (* `Permanent *)
 
-val to_b58check : contract -> string
+val to_b58check : t -> string
 
-val of_b58check : string -> contract tzresult
+val of_b58check : string -> t tzresult
 
-val pp : Format.formatter -> contract -> unit
+val pp : Format.formatter -> t -> unit
 
-val pp_short : Format.formatter -> contract -> unit
+val pp_short : Format.formatter -> t -> unit
 
 (** {2 Serializers} *)
 
-val encoding : contract Data_encoding.t
+val encoding : t Data_encoding.t
 
 (** [cases f g] exports the {!Data_encoding.cases} used to define {!encoding}.
 
     The only reason why we export that is to let {!Destination_repr.encoding}
     use it. This allows the latter to be compatible with {!encoding}, which
     is of key importance for backward compatibility reasons. *)
-val cases :
-  ('a -> contract option) -> (contract -> 'a) -> 'a Data_encoding.case list
+val cases : ('a -> t option) -> (t -> 'a) -> 'a Data_encoding.case list
 
-val rpc_arg : contract RPC_arg.arg
+val rpc_arg : t RPC_arg.arg
 
 module Index : Storage_description.INDEX with type t = t
diff --git a/src/proto_alpha/lib_protocol/contract_services.ml b/src/proto_alpha/lib_protocol/contract_services.ml
index 1f177396e90dd94ed7f6136150f33301c1b60279..5c84635f53014b8335b9d377552b4f8206d3288d 100644
--- a/src/proto_alpha/lib_protocol/contract_services.ml
+++ b/src/proto_alpha/lib_protocol/contract_services.ml
@@ -290,19 +290,19 @@ let[@coq_axiom_with_reason "gadt"] register () =
   register0 ~chunked:true S.list (fun ctxt () () -> Contract.list ctxt >|= ok) ;
   let register_field ~chunked s f =
     opt_register1 ~chunked s (fun ctxt contract () () ->
-        Contract.exists ctxt contract >>=? function
+        Contract.exists ctxt contract >>= function
         | true -> f ctxt contract >|=? Option.some
         | false -> return_none)
   in
   let register_field_with_query ~chunked s f =
     opt_register1 ~chunked s (fun ctxt contract query () ->
-        Contract.exists ctxt contract >>=? function
+        Contract.exists ctxt contract >>= function
         | true -> f ctxt contract query >|=? Option.some
         | false -> return_none)
   in
   let register_opt_field ~chunked s f =
     opt_register1 ~chunked s (fun ctxt contract () () ->
-        Contract.exists ctxt contract >>=? function
+        Contract.exists ctxt contract >>= function
         | true -> f ctxt contract
         | false -> return_none)
   in
diff --git a/src/proto_alpha/lib_protocol/contract_storage.ml b/src/proto_alpha/lib_protocol/contract_storage.ml
index 71dcf5dbf3062effa10b48e7c96eccfc340d920f..3225ef3ee908787554d296bcb0deeb575009fd6a 100644
--- a/src/proto_alpha/lib_protocol/contract_storage.ml
+++ b/src/proto_alpha/lib_protocol/contract_storage.ml
@@ -26,14 +26,13 @@
 
 type error +=
   | (* `Temporary *)
-      Balance_too_low of
-      Contract_repr.contract * Tez_repr.t * Tez_repr.t
+      Balance_too_low of Contract_repr.t * Tez_repr.t * Tez_repr.t
   | (* `Temporary *)
-      Counter_in_the_past of Contract_repr.contract * Z.t * Z.t
+      Counter_in_the_past of Contract_repr.t * Z.t * Z.t
   | (* `Branch *)
-      Counter_in_the_future of Contract_repr.contract * Z.t * Z.t
+      Counter_in_the_future of Contract_repr.t * Z.t * Z.t
   | (* `Temporary *)
-      Non_existing_contract of Contract_repr.contract
+      Non_existing_contract of Contract_repr.t
   | (* `Branch *)
       Empty_implicit_contract of Signature.Public_key_hash.t
   | (* `Branch *)
@@ -479,23 +478,20 @@ let delete c contract =
       Storage.Contract.Paid_storage_space.remove c contract >>= fun c ->
       Storage.Contract.Used_storage_space.remove c contract >|= ok
 
-let allocated c contract =
-  Storage.Contract.Spendable_balance.find c contract >>=? function
-  | None -> return_false
-  | Some _ -> return_true
+let allocated c contract = Storage.Contract.Spendable_balance.mem c contract
 
 let exists c contract =
   match Contract_repr.is_implicit contract with
-  | Some _ -> return_true
+  | Some _ -> Lwt.return_true
   | None -> allocated c contract
 
 let must_exist c contract =
-  exists c contract >>=? function
+  exists c contract >>= function
   | true -> return_unit
   | false -> fail (Non_existing_contract contract)
 
 let must_be_allocated c contract =
-  allocated c contract >>=? function
+  allocated c contract >>= function
   | true -> return_unit
   | false -> (
       match Contract_repr.is_implicit contract with
@@ -511,9 +507,10 @@ let fresh_contract_from_current_nonce c =
 let originated_from_current_nonce ~since:ctxt_since ~until:ctxt_until =
   Raw_context.get_origination_nonce ctxt_since >>?= fun since ->
   Raw_context.get_origination_nonce ctxt_until >>?= fun until ->
-  List.filter_es
+  List.filter_s
     (fun contract -> exists ctxt_until contract)
     (Contract_repr.originated_contracts ~since ~until)
+  >|= ok
 
 let check_counter_increment c manager counter =
   let contract = Contract_repr.implicit_contract manager in
diff --git a/src/proto_alpha/lib_protocol/contract_storage.mli b/src/proto_alpha/lib_protocol/contract_storage.mli
index 660fbc4a407c62d14c50059acf38991193722744..48421c4a1619272efa56a7186e427989220a30f0 100644
--- a/src/proto_alpha/lib_protocol/contract_storage.mli
+++ b/src/proto_alpha/lib_protocol/contract_storage.mli
@@ -28,9 +28,9 @@
 
 type error +=
   | (* `Branch *)
-      Counter_in_the_future of Contract_repr.contract * Z.t * Z.t
+      Counter_in_the_future of Contract_repr.t * Z.t * Z.t
   | (* `Temporary *)
-      Non_existing_contract of Contract_repr.contract
+      Non_existing_contract of Contract_repr.t
   | (* `Permanent *)
       Inconsistent_public_key of
       Signature.Public_key.t * Signature.Public_key.t
@@ -38,11 +38,11 @@ type error +=
 
 (** [allocated ctxt contract] returns [true] if and only if the
    contract is stored in [Storage.Contract.Balance]. *)
-val allocated : Raw_context.t -> Contract_repr.t -> bool tzresult Lwt.t
+val allocated : Raw_context.t -> Contract_repr.t -> bool Lwt.t
 
 (** [exists ctxt contract] returns [true] if and only if either the
    contract is originated or it is (implicit and) "allocated". *)
-val exists : Raw_context.t -> Contract_repr.t -> bool tzresult Lwt.t
+val exists : Raw_context.t -> Contract_repr.t -> bool Lwt.t
 
 (** [must_exist ctxt contract] fails with the [Non_existing_contract] error if
     [exists ctxt contract] returns [false]. Even though this function is
diff --git a/src/proto_alpha/lib_protocol/liquidity_baking_migration.ml b/src/proto_alpha/lib_protocol/liquidity_baking_migration.ml
index dd44969f8656fc04dc0aa96f357ea18f8ae56238..ad3717117a3c6ecc640bcf583d45bc643fa1269b 100644
--- a/src/proto_alpha/lib_protocol/liquidity_baking_migration.ml
+++ b/src/proto_alpha/lib_protocol/liquidity_baking_migration.ml
@@ -175,7 +175,7 @@ let first_bootstrap_account =
 
 let check_tzBTC ~typecheck current_level ctxt f =
   Contract_repr.of_b58check mainnet_tzBTC_address >>?= fun tzBTC ->
-  Contract_storage.exists ctxt tzBTC >>=? function
+  Contract_storage.exists ctxt tzBTC >>= function
   | true ->
       (* If tzBTC exists, we're on mainnet and we use it as the token address in the CPMM. *)
       f ctxt tzBTC []
diff --git a/src/proto_alpha/lib_protocol/liquidity_baking_storage.ml b/src/proto_alpha/lib_protocol/liquidity_baking_storage.ml
index 450e28390abd6b2d8fbb836ba8ec62d4048d9790..2c78115b223aa72152c19e169f8827bab8013106 100644
--- a/src/proto_alpha/lib_protocol/liquidity_baking_storage.ml
+++ b/src/proto_alpha/lib_protocol/liquidity_baking_storage.ml
@@ -34,7 +34,7 @@ let get_toggle_ema ctxt =
 
 let on_cpmm_exists ctxt f =
   get_cpmm_address ctxt >>=? fun cpmm_contract ->
-  Contract_storage.exists ctxt cpmm_contract >>=? function
+  Contract_storage.exists ctxt cpmm_contract >>= function
   | false ->
       (* do nothing if the cpmm is not found *)
       return (ctxt, [])
diff --git a/src/proto_alpha/lib_protocol/script_typed_ir.ml b/src/proto_alpha/lib_protocol/script_typed_ir.ml
index 6c7e45d3c81038642ce394879d25a8c82835842a..b1d02fdaea88eb7f1301b1266a370ee9c6d54650 100644
--- a/src/proto_alpha/lib_protocol/script_typed_ir.ml
+++ b/src/proto_alpha/lib_protocol/script_typed_ir.ml
@@ -1389,7 +1389,7 @@ and 'kind manager_operation =
       -> Kind.delegation manager_operation
 
 and 'kind internal_operation = {
-  source : Contract.contract;
+  source : Contract.t;
   operation : 'kind manager_operation;
   nonce : int;
 }
diff --git a/src/proto_alpha/lib_protocol/script_typed_ir.mli b/src/proto_alpha/lib_protocol/script_typed_ir.mli
index f2d0f2b2f7484771dbfb9bcd4a086a6b2ccebd67..547886e26bb647f46dd7ff7ebf7000899258d330 100644
--- a/src/proto_alpha/lib_protocol/script_typed_ir.mli
+++ b/src/proto_alpha/lib_protocol/script_typed_ir.mli
@@ -1522,7 +1522,7 @@ and 'kind manager_operation =
       -> Kind.delegation manager_operation
 
 and 'kind internal_operation = {
-  source : Contract.contract;
+  source : Contract.t;
   operation : 'kind manager_operation;
   nonce : int;
 }
diff --git a/src/proto_alpha/lib_protocol/test/helpers/liquidity_baking_machine.ml b/src/proto_alpha/lib_protocol/test/helpers/liquidity_baking_machine.ml
index 5459e68cfd616e5052e3813b21a89ba425e2391a..958e24ef27c439b4195d920625710eeefe64f14a 100644
--- a/src/proto_alpha/lib_protocol/test/helpers/liquidity_baking_machine.ml
+++ b/src/proto_alpha/lib_protocol/test/helpers/liquidity_baking_machine.ml
@@ -119,10 +119,6 @@ let far_future = Script_timestamp.of_zint (Z.of_int 42_000)
 (* --------------------------------------------------------------------------- *)
 
 (** {1 Miscellaneous Helpers} *)
-
-let is_implicit_exn account =
-  match Contract.is_implicit account with Some k -> k | _ -> assert false
-
 module List_helpers = struct
   let rec zip l r =
     match (l, r) with
@@ -764,7 +760,7 @@ module ConcreteBaseMachine :
 
   let bake ~invariant ~baker ops env blk =
     Incremental.begin_construction
-      ~policy:(Block.By_account (is_implicit_exn baker))
+      ~policy:(Block.By_account (Context.Contract.pkh baker))
       blk
     >>= fun incr ->
     fold_m Incremental.add_operation incr ops >>= fun incr ->
diff --git a/src/proto_alpha/lib_protocol/test/helpers/op.mli b/src/proto_alpha/lib_protocol/test/helpers/op.mli
index ef2354bd5a1b84aa743af14bd2b1441434ebbd1b..5a4165ccb78090cc5a30748fc2c9032f89daec2b 100644
--- a/src/proto_alpha/lib_protocol/test/helpers/op.mli
+++ b/src/proto_alpha/lib_protocol/test/helpers/op.mli
@@ -125,10 +125,10 @@ val contract_origination :
   ?gas_limit:Gas.Arith.integral ->
   ?storage_limit:Z.t ->
   Context.t ->
-  Contract.contract ->
-  (Operation.packed * Contract.contract) tzresult Lwt.t
+  Contract.t ->
+  (Operation.packed * Contract.t) tzresult Lwt.t
 
-val originated_contract : Operation.packed -> Contract.contract
+val originated_contract : Operation.packed -> Contract.t
 
 val register_global_constant :
   ?counter:Z.t ->
diff --git a/src/proto_alpha/lib_protocol/test/integration/consensus/test_delegation.ml b/src/proto_alpha/lib_protocol/test/integration/consensus/test_delegation.ml
index 2b46c3e9767429ca6c52950d221915ca63159f9c..2810de0eb97ea32909bd30813f2533de391df9b1 100644
--- a/src/proto_alpha/lib_protocol/test/integration/consensus/test_delegation.ml
+++ b/src/proto_alpha/lib_protocol/test/integration/consensus/test_delegation.ml
@@ -501,9 +501,7 @@ let test_unregistered_delegate_key_init_delegation ~fee () =
 let test_unregistered_delegate_key_switch_delegation ~fee () =
   Context.init1 () >>=? fun (b, bootstrap) ->
   Incremental.begin_construction b >>=? fun i ->
-  let bootstrap_pkh =
-    Contract.is_implicit bootstrap |> WithExceptions.Option.get ~loc:__LOC__
-  in
+  let bootstrap_pkh = Context.Contract.pkh bootstrap in
   let unregistered_account = Account.new_account () in
   let unregistered_pkh = Account.(unregistered_account.pkh) in
   let impl_contract = Contract.implicit_contract unregistered_pkh in
@@ -620,9 +618,7 @@ let test_unregistered_delegate_key_init_delegation_credit ~fee ~amount () =
 let test_unregistered_delegate_key_switch_delegation_credit ~fee ~amount () =
   Context.init1 () >>=? fun (b, bootstrap) ->
   Incremental.begin_construction b >>=? fun i ->
-  let bootstrap_pkh =
-    Contract.is_implicit bootstrap |> WithExceptions.Option.get ~loc:__LOC__
-  in
+  let bootstrap_pkh = Context.Contract.pkh bootstrap in
   let unregistered_account = Account.new_account () in
   let unregistered_pkh = Account.(unregistered_account.pkh) in
   let impl_contract = Contract.implicit_contract unregistered_pkh in
@@ -756,9 +752,7 @@ let test_unregistered_delegate_key_switch_delegation_credit_debit ~fee ~amount
     () =
   Context.init1 () >>=? fun (b, bootstrap) ->
   Incremental.begin_construction b >>=? fun i ->
-  let bootstrap_pkh =
-    Contract.is_implicit bootstrap |> WithExceptions.Option.get ~loc:__LOC__
-  in
+  let bootstrap_pkh = Context.Contract.pkh bootstrap in
   let unregistered_account = Account.new_account () in
   let unregistered_pkh = Account.(unregistered_account.pkh) in
   let impl_contract = Contract.implicit_contract unregistered_pkh in
diff --git a/src/proto_alpha/lib_protocol/test/integration/consensus/test_helpers_rpcs.ml b/src/proto_alpha/lib_protocol/test/integration/consensus/test_helpers_rpcs.ml
index 78df0e7cc262bd7af38dc12ca26023bf7d16dd29..367aa44d4ecfcda314d71bc617e5e730cdfd3c48 100644
--- a/src/proto_alpha/lib_protocol/test/integration/consensus/test_helpers_rpcs.ml
+++ b/src/proto_alpha/lib_protocol/test/integration/consensus/test_helpers_rpcs.ml
@@ -32,9 +32,6 @@
     Subject:    On RPCs.
 *)
 
-open Protocol
-open Alpha_context
-
 (* Test the baking_rights RPC.
    Future levels or cycles are not tested because it's hard in this framework,
    using only RPCs, to fabricate them. *)
@@ -49,7 +46,7 @@ let test_baking_rights () =
   get Block.rpc_ctxt b ~all:true ~max_round >>=? fun rights ->
   assert (Compare.List_length_with.(rights = max_round + 1)) ;
   (* filtering by delegate *)
-  let d = Contract.is_implicit c1 |> WithExceptions.Option.get ~loc:__LOC__ in
+  let d = Context.Contract.pkh c1 in
   get Block.rpc_ctxt b ~all:true ~delegates:[d] >>=? fun rights ->
   assert (List.for_all (fun {delegate; _} -> delegate = d) rights) ;
   (* filtering by cycle *)
diff --git a/src/proto_alpha/lib_protocol/test/integration/michelson/test_sapling.ml b/src/proto_alpha/lib_protocol/test/integration/michelson/test_sapling.ml
index 704381c37c1aeeddda5a5ce649f4106abdc5a865..b05e03bf67dcbd34a832b4d92f0b111362e37a71 100644
--- a/src/proto_alpha/lib_protocol/test/integration/michelson/test_sapling.ml
+++ b/src/proto_alpha/lib_protocol/test/integration/michelson/test_sapling.ml
@@ -642,10 +642,7 @@ module Interpreter_tests = struct
         (fun addr -> Tezos_sapling.Forge.make_output addr 1L (Bytes.create 8))
         list_addr
     in
-    (let pkh =
-       Alpha_context.Contract.is_implicit src1
-       |> WithExceptions.Option.get ~loc:__LOC__
-     in
+    (let pkh = Context.Contract.pkh src1 in
      (* dummy context used only for pack_data *)
      Block.alpha_context
        [(Account.activator_account, Tez.of_mutez_exn 100_000_000_000L)]
@@ -914,10 +911,7 @@ module Interpreter_tests = struct
     Incremental.add_operation incr operation >>=? fun incr ->
     (* We need to manually get the counter here *)
     let ctx = Incremental.alpha_ctxt incr in
-    let pkh =
-      Alpha_context.Contract.is_implicit src
-      |> WithExceptions.Option.get ~loc:__LOC__
-    in
+    let pkh = Context.Contract.pkh src in
     Alpha_context.Contract.get_counter ctx pkh >>= wrap >>=? fun counter ->
     Op.transaction
       ~counter
diff --git a/src/proto_alpha/lib_protocol/test/integration/michelson/test_ticket_accounting.ml b/src/proto_alpha/lib_protocol/test/integration/michelson/test_ticket_accounting.ml
index 0c1a1b0816ad0f59695a9a46483f46f7caa9d937..88c72683af3b47ebdfb17a92faa31fd3971b9090 100644
--- a/src/proto_alpha/lib_protocol/test/integration/michelson/test_ticket_accounting.ml
+++ b/src/proto_alpha/lib_protocol/test/integration/michelson/test_ticket_accounting.ml
@@ -170,11 +170,7 @@ let init () =
 (** Initializes one address for operations and one baker. *)
 let init_for_operation () =
   Context.init2 ~consensus_threshold:0 () >|=? fun (block, (src0, src1)) ->
-  let baker =
-    match Alpha_context.Contract.is_implicit src0 with
-    | Some v -> v
-    | None -> assert false
-  in
+  let baker = Context.Contract.pkh src0 in
   (baker, src1, block)
 
 let two_ticketers block =
diff --git a/src/proto_alpha/lib_protocol/test/integration/michelson/test_ticket_operations_diff.ml b/src/proto_alpha/lib_protocol/test/integration/michelson/test_ticket_operations_diff.ml
index 8a459257bc42dad2de8020d1622a601145e8d32b..2d7a6be06fdcbbfb9960fb1254bfc43781ecb9cc 100644
--- a/src/proto_alpha/lib_protocol/test/integration/michelson/test_ticket_operations_diff.ml
+++ b/src/proto_alpha/lib_protocol/test/integration/michelson/test_ticket_operations_diff.ml
@@ -182,11 +182,7 @@ let string_token ~ticketer content =
 let init ?tx_rollup_enable () =
   Context.init2 ?tx_rollup_enable ~consensus_threshold:0 ()
   >|=? fun (block, (src0, src1)) ->
-  let baker =
-    match Alpha_context.Contract.is_implicit src0 with
-    | Some v -> v
-    | None -> assert false
-  in
+  let baker = Context.Contract.pkh src0 in
   (baker, src1, block)
 
 let originate block ~script ~storage ~src ~baker ~forges_tickets =
diff --git a/src/proto_alpha/lib_protocol/test/integration/operations/test_failing_noop.ml b/src/proto_alpha/lib_protocol/test/integration/operations/test_failing_noop.ml
index 95bd9ea38a68265e4a4e1a7c4d6ce688fd48eff8..798c949977fe70025f4b21a23999b24b9dd536db 100644
--- a/src/proto_alpha/lib_protocol/test/integration/operations/test_failing_noop.ml
+++ b/src/proto_alpha/lib_protocol/test/integration/operations/test_failing_noop.ml
@@ -37,21 +37,16 @@
                   applied.
  *)
 
-open Protocol
-open Alpha_context
-
 (** try to apply a failing_noop and assert that the operation fails *)
 let failing_noop_must_fail_when_injected () =
   Context.init1 () >>=? fun (blk, contract) ->
-  Contract.is_implicit contract |> function
-  | None -> Alcotest.fail "only implicit accounts can sign"
-  | Some source ->
-      Op.failing_noop (B blk) source "tezos" >>=? fun operation ->
-      Block.bake ~operation blk >>= fun res ->
-      Assert.proto_error_with_info
-        ~loc:__LOC__
-        res
-        "Failing_noop operations are not executed by the protocol"
+  let source = Context.Contract.pkh contract in
+  Op.failing_noop (B blk) source "tezos" >>=? fun operation ->
+  Block.bake ~operation blk >>= fun res ->
+  Assert.proto_error_with_info
+    ~loc:__LOC__
+    res
+    "Failing_noop operations are not executed by the protocol"
 
 let tests =
   [Tztest.tztest "injection fails" `Quick failing_noop_must_fail_when_injected]
diff --git a/src/proto_alpha/lib_protocol/test/integration/operations/test_tx_rollup.ml b/src/proto_alpha/lib_protocol/test/integration/operations/test_tx_rollup.ml
index 94b403ed8dadbdf1cbbcce10588bdea6d0d2c955..99a82b4964b5c5c52761ef73556750d00c34ecf2 100644
--- a/src/proto_alpha/lib_protocol/test/integration/operations/test_tx_rollup.ml
+++ b/src/proto_alpha/lib_protocol/test/integration/operations/test_tx_rollup.ml
@@ -56,11 +56,6 @@ let check_proto_error_f f t =
     equals [e]. *)
 let check_proto_error e t = check_proto_error_f (( = ) e) t
 
-let is_implicit_exn x =
-  match Alpha_context.Contract.is_implicit x with
-  | Some x -> x
-  | None -> raise (Invalid_argument "is_implicit_exn")
-
 (** [test_disable_feature_flag] try to originate a tx rollup with the feature
     flag is deactivated and check it fails *)
 let test_disable_feature_flag () =
@@ -106,7 +101,7 @@ let parsing_tests =
       initial_storage
       contract
       b
-      (is_implicit_exn contract)
+      (Context.Contract.pkh contract)
     >>= fun res ->
     if not tx_rollup_enable then
       Assert.error ~loc:__LOC__ res (function
@@ -352,7 +347,7 @@ let make_deposit b tx_rollup l1_src addr =
     "Unit"
     l1_src
     b
-    (is_implicit_exn l1_src)
+    (Context.Contract.pkh l1_src)
   >>=? fun (contract, b) ->
   let parameters = print_deposit_arg (`Typed tx_rollup) (`Hash addr) in
   let fee = Test_tez.of_int 10 in
@@ -370,7 +365,7 @@ let make_deposit b tx_rollup l1_src addr =
   >>=? fun ticket_hash ->
   let (deposit, cumulated_size) =
     Tx_rollup_message.make_deposit
-      (is_implicit_exn l1_src)
+      (Context.Contract.pkh l1_src)
       (Tx_rollup_l2_address.Indexable.value addr)
       ticket_hash
       (Tx_rollup_l2_qty.of_int64_exn 100_000L)
@@ -422,7 +417,7 @@ let make_incomplete_commitment_for_batch context level tx_rollup withdraw_list =
 
 (** Check that the given contract has [count] pending bonded commitments *)
 let check_bond ctxt tx_rollup contract count =
-  let pkh = is_implicit_exn contract in
+  let pkh = Context.Contract.pkh contract in
   Tx_rollup_commitment.pending_bonded_commitments ctxt tx_rollup pkh
   >>=?? fun (_, pending) ->
   Alcotest.(check int "Pending bonded commitment count correct" count pending) ;
@@ -484,14 +479,15 @@ module Nat_ticket = struct
   let withdrawal ctxt ~ticketer ?(claimer = ticketer) ?(amount = amount)
       tx_rollup : (Tx_rollup_withdraw.t * Tx_rollup_reveal.t) tzresult Lwt.t =
     ticket_hash ctxt ~ticketer ~tx_rollup >|=? fun ticket_hash ->
-    ( Tx_rollup_withdraw.{claimer = is_implicit_exn claimer; ticket_hash; amount},
+    let claimer = Context.Contract.pkh claimer in
+    ( Tx_rollup_withdraw.{claimer; ticket_hash; amount},
       Tx_rollup_reveal.
         {
           contents = Script.lazy_expr contents;
           ty = Script.lazy_expr ty;
           ticketer;
           amount;
-          claimer = is_implicit_exn claimer;
+          claimer;
         } )
 
   let init_deposit_contract amount block account =
@@ -525,7 +521,7 @@ module Nat_ticket = struct
         contents_nat
     in
     Contract_helpers.originate_contract_from_string
-      ~baker:(is_implicit_exn account)
+      ~baker:(Context.Contract.pkh account)
       ~source_contract:account
       ~script
       ~storage:"Unit"
@@ -955,7 +951,7 @@ let test_inbox_count_too_big () =
     "Unit"
     contract
     b
-    (is_implicit_exn contract)
+    (Context.Contract.pkh contract)
   >>=? fun (deposit_contract, b) ->
   Incremental.begin_construction b >>=? fun i ->
   let rec fill_inbox i counter n =
@@ -1055,7 +1051,7 @@ let test_additional_space_allocation_for_valid_deposit () =
     "Unit"
     account
     b
-    (is_implicit_exn account)
+    (Context.Contract.pkh account)
   >>=? fun (contract, b) ->
   let parameters = print_deposit_arg (`Typed tx_rollup) (`Hash pkh) in
   let fee = Test_tez.of_int 10 in
@@ -1086,7 +1082,7 @@ let test_valid_deposit_inexistant_rollup () =
     "Unit"
     account
     b
-    (is_implicit_exn account)
+    (Context.Contract.pkh account)
   >>=? fun (contract, b) ->
   Incremental.begin_construction b >>=? fun i ->
   let parameters =
@@ -1115,7 +1111,7 @@ let test_invalid_deposit_not_ticket () =
     "Unit"
     account
     b
-    (is_implicit_exn account)
+    (Context.Contract.pkh account)
   >>=? fun (contract, b) ->
   Incremental.begin_construction b >>=? fun i ->
   let parameters = print_deposit_arg (`Typed tx_rollup) (`Hash pkh) in
@@ -1185,7 +1181,7 @@ let test_invalid_deposit_too_big_ticket () =
     "Unit"
     account
     b
-    (is_implicit_exn account)
+    (Context.Contract.pkh account)
   >>=? fun (contract, b) ->
   Incremental.begin_construction b >>=? fun i ->
   let ticket_contents =
@@ -1236,7 +1232,7 @@ let test_invalid_deposit_too_big_ticket_type () =
     "Unit"
     account
     b
-    (is_implicit_exn account)
+    (Context.Contract.pkh account)
   >>=? fun (contract, b) ->
   Incremental.begin_construction b >>=? fun i ->
   let ticket_contents =
@@ -1293,7 +1289,7 @@ let test_valid_deposit_big_ticket () =
     "Unit"
     account
     b
-    (is_implicit_exn account)
+    (Context.Contract.pkh account)
   >>=? fun (contract, b) ->
   Incremental.begin_construction b >>=? fun i ->
   let ticket_contents =
@@ -1333,7 +1329,7 @@ let test_invalid_entrypoint () =
     "Unit"
     account
     b
-    (is_implicit_exn account)
+    (Context.Contract.pkh account)
   >>=? fun (contract, b) ->
   Incremental.begin_construction b >>=? fun i ->
   let parameters = print_deposit_arg (`Typed tx_rollup) (`Hash pkh) in
@@ -1358,7 +1354,7 @@ let test_invalid_l2_address () =
     "Unit"
     account
     b
-    (is_implicit_exn account)
+    (Context.Contract.pkh account)
   >>=? fun (contract, b) ->
   Incremental.begin_construction b >>=? fun i ->
   let parameters =
@@ -1386,7 +1382,7 @@ let test_valid_deposit_invalid_amount () =
     "Unit"
     account
     b
-    (is_implicit_exn account)
+    (Context.Contract.pkh account)
   >>=? fun (contract, b) ->
   Incremental.begin_construction b >>=? fun i ->
   let parameters = print_deposit_arg (`Typed tx_rollup) (`Hash pkh) in
@@ -1529,7 +1525,7 @@ let test_finalization () =
     the wrong batch count and ensures that that fails. *)
 let test_commitment_duplication () =
   context_init2 () >>=? fun (b, (contract1, contract2)) ->
-  let pkh1 = is_implicit_exn contract1 in
+  let pkh1 = Context.Contract.pkh contract1 in
   originate b contract1 >>=? fun (b, tx_rollup) ->
   Context.Contract.balance (B b) contract1 >>=? fun balance ->
   Context.Contract.balance (B b) contract2 >>=? fun balance2 ->
@@ -1934,7 +1930,7 @@ let test_full_inbox () =
     allows bonds to be returned. *)
 let test_bond_finalization () =
   context_init1 () >>=? fun (b, contract1) ->
-  let pkh1 = is_implicit_exn contract1 in
+  let pkh1 = Context.Contract.pkh contract1 in
   originate b contract1 >>=? fun (b, tx_rollup) ->
   Context.Contract.balance (B b) contract1 >>=? fun balance ->
   (* Transactions in block 2, 3, 4 *)
@@ -3270,7 +3266,7 @@ module Rejection = struct
     >>=? fun (b, account, _, tx_rollup, store, ticket_hash) ->
     hash_tree_from_store store >>= fun l2_context_hash ->
     (* 1. Create a batch with [n_withdraw] withdrawals. *)
-    let destination = is_implicit_exn account in
+    let destination = Context.Contract.pkh account in
     let qty = Tx_rollup_l2_qty.one in
     let operation =
       let open Tx_rollup_l2_batch.V1 in
@@ -3968,7 +3964,7 @@ module Withdraw = struct
            Nat_ticket.ty_str)
       ~storage:"None"
       ~source_contract:account1
-      ~baker:(is_implicit_exn account1)
+      ~baker:(Context.Contract.pkh account1)
       block
     >>=? fun (withdraw_contract, _script, block) ->
     return
@@ -4049,7 +4045,7 @@ module Withdraw = struct
              } |}
       ~storage:"{}"
       ~source_contract:account
-      ~baker:(is_implicit_exn account)
+      ~baker:(Context.Contract.pkh account)
       block
     >>=? fun (forge_withdraw_deposit_contract, _script, block) ->
     return (forge_withdraw_deposit_contract, block)
@@ -4141,7 +4137,7 @@ module Withdraw = struct
            Nat_ticket.ty_str)
       ~storage:"Unit"
       ~source_contract:account1
-      ~baker:(is_implicit_exn account1)
+      ~baker:(Context.Contract.pkh account1)
       block
     >>=? fun (withdraw_dropping_contract, _script, block) ->
     let token_one = Nat_ticket.ex_token ~ticketer:deposit_contract in
@@ -5172,7 +5168,7 @@ module Withdraw = struct
     let pkh_str = Tx_rollup_l2_address.to_b58check pkh in
     Nat_ticket.init_deposit_contract (Z.of_int64 max) b account1
     >>=? fun (deposit_contract, _script, b) ->
-    let deposit_pkh = assert_some @@ Contract.is_implicit account1 in
+    let deposit_pkh = Context.Contract.pkh account1 in
     let deposit b =
       Nat_ticket.deposit_op b tx_rollup pkh_str account1 deposit_contract
       >>=? fun operation -> Block.bake ~operation b
@@ -5251,7 +5247,7 @@ module Withdraw = struct
     originate b account1 >>=? fun (b, tx_rollup) ->
     Nat_ticket.init_deposit_contract (Z.of_int64 max) b account1
     >>=? fun (deposit_contract, _script, b) ->
-    let deposit_pkh = assert_some @@ Contract.is_implicit account1 in
+    let deposit_pkh = Context.Contract.pkh account1 in
     let deposit b pkh =
       let pkh_str = Tx_rollup_l2_address.to_b58check pkh in
       Nat_ticket.deposit_op b tx_rollup pkh_str account1 deposit_contract
diff --git a/src/proto_alpha/lib_protocol/token.ml b/src/proto_alpha/lib_protocol/token.ml
index 67f1083a0039d86df1cb964af813d6e05d37b957..325dea7a2800f6193c9e8f3097d409e94d0e6a79 100644
--- a/src/proto_alpha/lib_protocol/token.ml
+++ b/src/proto_alpha/lib_protocol/token.ml
@@ -58,15 +58,15 @@ type sink = [infinite_sink | container]
 let allocated ctxt stored =
   match stored with
   | `Contract contract ->
-      Contract_storage.allocated ctxt contract >|=? fun allocated ->
-      (ctxt, allocated)
+      Contract_storage.allocated ctxt contract >|= fun allocated ->
+      ok (ctxt, allocated)
   | `Collected_commitments bpkh ->
-      Commitment_storage.exists ctxt bpkh >|= ok >|=? fun allocated ->
-      (ctxt, allocated)
+      Commitment_storage.exists ctxt bpkh >|= fun allocated ->
+      ok (ctxt, allocated)
   | `Delegate_balance delegate ->
       let contract = Contract_repr.implicit_contract delegate in
-      Contract_storage.allocated ctxt contract >|=? fun allocated ->
-      (ctxt, allocated)
+      Contract_storage.allocated ctxt contract >|= fun allocated ->
+      ok (ctxt, allocated)
   | `Frozen_deposits delegate ->
       let contract = Contract_repr.implicit_contract delegate in
       Frozen_deposits_storage.allocated ctxt contract >|= fun allocated ->