diff --git a/src/api.ml b/src/api.ml
index 77a38f33..871454c7 100644
--- a/src/api.ml
+++ b/src/api.ml
@@ -1,4 +1,5 @@
 (* TODO
+
    ppx?
 
    normalized JSON-object
@@ -21,10 +22,10 @@
    option: correct use opt_mem or Jsont.option
    number
      - number is "float", but we probably want int everywhere instead
-     - numeric values capped at 2^53 -1 inclusive because json
-     *)
+     - numeric values capped at 2^53 -1 inclusive because json *)
 open Crypto
 open Bin_signature
+open Jsont.Object
 
 let encode_exn jsont v = Jsont_bytesrw.encode_string jsont v |> Result.get_ok
 let encode jsont v = Jsont_bytesrw.encode_string jsont v
@@ -160,7 +161,6 @@ module CurrencySpecification = struct
     in
     let alt_unit_names v = v.alt_unit_names in
     let common_amounts v = v.common_amounts in
-    let open Jsont.Object in
     map ~kind:"CurrencySpecification" make
     |> mem "name" Jsont.string ~enc:name
     |> mem "num_fractional_input_digits" Jsont.int
@@ -210,7 +210,6 @@ module ExchangeVersionResponse = struct
     let currency_specification v = v.currency_specification in
     let supported_kyc_requirements v = v.supported_kyc_requirements in
     let aml_spa_dialect v = v.aml_spa_dialect in
-    let open Jsont.Object in
     map ~kind:"ExchangeVersionResponse" make
     |> mem "version" Jsont.string ~enc:version
     |> mem "implementation" (Jsont.option Jsont.string) ~enc:implementation
@@ -272,7 +271,6 @@ module DenominationKey = struct
   let of_rsa v = Rsa v
 
   let jsont =
-    let open Jsont.Object in
     let rsa = Case.map "RSA" RsaDenominationKey.jsont ~dec:of_rsa in
     let cs = Case.map "CS" CSDenominationKey.jsont ~dec:of_cs in
     let enc_case = function Rsa v -> Case.value rsa v in
@@ -300,7 +298,6 @@ module FutureSignKey = struct
     let stamp_expire v = v.stamp_expire in
     let stamp_end v = v.stamp_end in
     let signkey_secmod_sig v = v.signkey_secmod_sig in
-    let open Jsont.Object in
     map ~kind:"FutureSignKey" make
     |> mem "key" EddsaPublicKey.jsont ~enc:key
     |> mem "stamp_start" Timestamp.jsont ~enc:stamp_start
@@ -358,7 +355,6 @@ module FutureDenom = struct
     let fee_refresh t = t.fee_refresh in
     let fee_refund t = t.fee_refund in
     let denom_secmod_sig t = t.denom_secmod_sig in
-    let open Jsont.Object in
     map ~kind:"FutureDenom" make
     |> mem "section_name" Jsont.string ~enc:section_name
     |> mem "value" Amount.jsont ~enc:value
@@ -401,7 +397,6 @@ module FutureKeysResponse = struct
     let master_pub t = t.master_pub in
     let denom_secmod_public_key t = t.denom_secmod_public_key in
     let signkey_secmod_public_key t = t.signkey_secmod_public_key in
-    let open Jsont.Object in
     map ~kind:"FutureKeysResponse" make
     |> mem "future_denoms" (Jsont.list FutureDenom.jsont) ~enc:future_denoms
     |> mem "future_signkeys"
@@ -425,7 +420,6 @@ module SignKeySignature = struct
     let make key master_sig = { key; master_sig } in
     let key v = v.key in
     let master_sig v = v.master_sig in
-    let open Jsont.Object in
     map ~kind:"SignKeySignature" make
     |> mem "key" EddsaPublicKey.jsont ~enc:key
     |> mem "master_sig" ExchangeSigningKeyValidityPS.jsont ~enc:master_sig
@@ -442,7 +436,6 @@ module DenomSignature = struct
     let make h_denom_pub master_sig = { h_denom_pub; master_sig } in
     let h_denom_pub v = v.h_denom_pub in
     let master_sig v = v.master_sig in
-    let open Jsont.Object in
     map ~kind:"DenomSignature" make
     |> mem "h_denom_pub" HashCode.jsont ~enc:h_denom_pub
     |> mem "master_sig" DenominationKeyValidityPS.jsont ~enc:master_sig
@@ -459,7 +452,6 @@ module MasterSignatures = struct
     let make denom_sigs signkey_sigs = { denom_sigs; signkey_sigs } in
     let denom_sigs v = v.denom_sigs in
     let signkey_sigs v = v.signkey_sigs in
-    let open Jsont.Object in
     map ~kind:"MasterSignatures" make
     |> mem "denom_sigs" (Jsont.list DenomSignature.jsont) ~enc:denom_sigs
     |> mem "signkey_sigs" (Jsont.list SignKeySignature.jsont) ~enc:signkey_sigs
@@ -472,7 +464,6 @@ module DenomRevocationSignature = struct
   let jsont =
     let make master_sig = { master_sig } in
     let enc v = v.master_sig in
-    let open Jsont.Object in
     map ~kind:"DenomRevocationSignature" make
     |> mem "master_sig" MasterDenominationKeyRevocationPS.jsont ~enc
     |> finish
@@ -484,7 +475,6 @@ module SignkeyRevocationSignature = struct
   let jsont =
     let make master_sig = { master_sig } in
     let enc v = v.master_sig in
-    let open Jsont.Object in
     map ~kind:"SignkeyRevocationSignature" make
     |> mem "master_sig" MasterSigningKeyRevocationPS.jsont ~enc
     |> finish
@@ -510,7 +500,6 @@ module AuditorSetupMessage = struct
     let auditor_pub v = v.auditor_pub in
     let master_sig v = v.master_sig in
     let validity_start v = v.validity_start in
-    let open Jsont.Object in
     map ~kind:"AuditorSetupMessage" make
     |> mem "auditor_url" Jsont.string ~enc:auditor_url
     |> mem "auditor_name" Jsont.string ~enc:auditor_name
@@ -531,7 +520,6 @@ module AuditorTeardownMessage = struct
     let make master_sig validity_end = { master_sig; validity_end } in
     let master_sig v = v.master_sig in
     let validity_end v = v.validity_end in
-    let open Jsont.Object in
     map ~kind:"AuditorTeardownMessage" make
     |> mem "master_sig" MasterDelAuditorPS.jsont ~enc:master_sig
     |> mem "validity_end" Timestamp.jsont ~enc:validity_end
@@ -569,7 +557,6 @@ module WireFeeSetupMessage = struct
     let fee_end v = v.fee_end in
     let closing_fee v = v.closing_fee in
     let wire_fee v = v.wire_fee in
-    let open Jsont.Object in
     map ~kind:"WireFeeSetupMessage" make
     |> mem "wire_method" Jsont.string ~enc:wire_method
     |> mem "master_sig_wire" MasterWireFeePS.jsont ~enc:master_sig_wire
@@ -618,7 +605,6 @@ module GlobalFees = struct
     let purse_account_limit v = v.purse_account_limit in
     let purse_timeout v = v.purse_timeout in
     let master_sig v = v.master_sig in
-    let open Jsont.Object in
     map ~kind:"GlobalFees" make
     |> mem "start_date" Timestamp.jsont ~enc:start_date
     |> mem "end_date" Timestamp.jsont ~enc:end_date
@@ -661,7 +647,6 @@ module WireSetupMessage = struct
     let validity_start v = v.validity_start in
     let bank_label v = v.bank_label in
     let priority v = v.priority in
-    let open Jsont.Object in
     map ~kind:"WireSetupMessage" make
     |> mem "payto_uri" Jsont.string ~enc:payto_uri
     |> mem "master_sig_wire" MasterWireDetailsPS.jsont ~enc:master_sig_wire
@@ -687,7 +672,6 @@ module WireTeardownMessage = struct
     let payto_uri v = v.payto_uri in
     let master_sig_del v = v.master_sig_del in
     let validity_end v = v.validity_end in
-    let open Jsont.Object in
     map ~kind:"WireTeardownMessage" make
     |> mem "payto_uri" Jsont.string ~enc:payto_uri
     |> mem "master_sig_del" MasterDelWirePS.jsont ~enc:master_sig_del
@@ -723,7 +707,6 @@ module DrainProfitsMessage = struct
     let master_sig v = v.master_sig in
     let date v = v.date in
     let amount v = v.amount in
-    let open Jsont.Object in
     map ~kind:"DrainProfitsMessage" make
     |> mem "debit_account_section" Jsont.string ~enc:debit_account_section
     |> mem "credit_payto_uri" Jsont.string ~enc:credit_payto_uri
@@ -762,7 +745,6 @@ module AmlOfficerSetup = struct
     let read_only v = v.read_only in
     let master_sig v = v.master_sig in
     let change_date v = v.change_date in
-    let open Jsont.Object in
     map ~kind:"AmlOfficerSetup" make
     |> mem "officer_pub" EddsaPublicKey.jsont ~enc:officer_pub
     |> mem "officer_name" Jsont.string ~enc:officer_name
@@ -804,7 +786,6 @@ module ExchangePartnerSetupRequest = struct
     let start_date v = v.start_date in
     let end_date v = v.end_date in
     let wad_fee v = v.wad_fee in
-    let open Jsont.Object in
     map ~kind:"ExchangePartnerSetupRequest" make
     |> mem "partner_base_url" Jsont.string ~enc:partner_base_url
     |> mem "partner_pub" EddsaPublicKey.jsont ~enc:partner_pub
@@ -849,7 +830,6 @@ module ExchangePartnerListEntry = struct
     let start_date v = v.start_date in
     let end_date v = v.end_date in
     let master_sig v = v.master_sig in
-    let open Jsont.Object in
     map ~kind:"ExchangePartnerListEntry" make
     |> mem "partner_base_url" Jsont.string ~enc:partner_base_url
     |> mem "partner_master_pub" EddsaPublicKey.jsont ~enc:partner_master_pub
@@ -879,7 +859,6 @@ module AggregateTransferFee = struct
     let start_date v = v.start_date in
     let end_date v = v.end_date in
     let sig_ v = v.sig_ in
-    let open Jsont.Object in
     map ~kind:"AggregateTransferFee" make
     |> mem "wire_fee" Amount.jsont ~enc:wire_fee
     |> mem "closing_fee" Amount.jsont ~enc:closing_fee
@@ -899,7 +878,6 @@ module AuditorDenominationKey = struct
     let make denom_pub_h auditor_sig = { denom_pub_h; auditor_sig } in
     let denom_pub_h v = v.denom_pub_h in
     let auditor_sig v = v.auditor_sig in
-    let open Jsont.Object in
     map ~kind:"AuditorDenominationKey" make
     |> mem "denom_pub_h" HashCode.jsont ~enc:denom_pub_h
     |> mem "auditor_sig" ExchangeKeyValidityPS.jsont ~enc:auditor_sig
@@ -922,7 +900,6 @@ module AuditorKeys = struct
     let auditor_url v = v.auditor_url in
     let auditor_name v = v.auditor_name in
     let denomination_keys v = v.denomination_keys in
-    let open Jsont.Object in
     map ~kind:"AuditorKeys" make
     |> mem "auditor_pub" EddsaPublicKey.jsont ~enc:auditor_pub
     |> mem "auditor_url" Jsont.string ~enc:auditor_url
@@ -951,7 +928,6 @@ module SignKey = struct
     let stamp_expire v = v.stamp_expire in
     let stamp_end v = v.stamp_end in
     let master_sig v = v.master_sig in
-    let open Jsont.Object in
     map ~kind:"SignKey" make
     |> mem "key" EddsaPublicKey.jsont ~enc:key
     |> mem "stamp_start" Timestamp.jsont ~enc:stamp_start
@@ -967,7 +943,6 @@ module RecoupDenoms = struct
   let jsont =
     let make h_denom_pub = { h_denom_pub } in
     let h_denom_pub v = v.h_denom_pub in
-    let open Jsont.Object in
     map ~kind:"RecoupDenoms" make
     |> mem "h_denom_pub" HashCode.jsont ~enc:h_denom_pub
     |> finish
@@ -1005,7 +980,6 @@ module RsaDenom = struct
     let stamp_expire_deposit v = v.stamp_expire_deposit in
     let stamp_expire_legal v = v.stamp_expire_legal in
     let lost v = v.lost in
-    let open Jsont.Object in
     map ~kind:"RsaDenom" make
     |> mem "rsa_pub" RsaPublicKey.jsont ~enc:rsa_pub
     |> mem "master_sig" DenominationKeyValidityPS.jsont ~enc:master_sig
@@ -1037,7 +1011,6 @@ module RsaDenomGroup = struct
     let fee_deposit v = v.fee_deposit in
     let fee_refresh v = v.fee_refresh in
     let fee_refund v = v.fee_refund in
-    let open Jsont.Object in
     map ~kind:"RsaDenomGroup" make
     |> mem "denoms" (Jsont.list RsaDenom.jsont) ~enc:denoms
     |> mem "value" Amount.jsont ~enc:value
@@ -1054,7 +1027,6 @@ module DenomGroup = struct
   let of_rsa v = Rsa v
 
   let jsont =
-    let open Jsont.Object in
     let rsa = Case.map "RSA" RsaDenomGroup.jsont ~dec:of_rsa in
     let enc_case = function Rsa v -> Case.value rsa v in
     let cases = Case.[ make rsa ] in
@@ -1079,7 +1051,6 @@ module AccountLimit = struct
     let timeframe v = v.timeframe in
     let threshold v = v.threshold in
     let soft_limit v = v.soft_limit in
-    let open Jsont.Object in
     map ~kind:"AccountLimit" make
     |> mem "operation_type" Account_operation.jsont ~enc:operation_type
     |> mem "timeframe" RelativeTime.jsont ~enc:timeframe
@@ -1094,7 +1065,6 @@ module ZeroLimitedOperation = struct
   let jsont =
     let make operation_type = { operation_type } in
     let operation_type v = v.operation_type in
-    let open Jsont.Object in
     map ~kind:"ZeroLimitedOperation" make
     |> mem "operation_type" Account_operation.jsont ~enc:operation_type
     |> finish
@@ -1115,7 +1085,6 @@ module RegexAccountRestriction = struct
     let payto_regex v = v.payto_regex in
     let human_hint v = v.human_hint in
     let human_hint_i18n v = v.human_hint_i18n in
-    let open Jsont.Object in
     map ~kind:"RegexAccountRestriction" make
     |> mem "payto_regex" Jsont.string ~enc:payto_regex
     |> mem "human_hint" Jsont.string ~enc:human_hint
@@ -1132,7 +1101,6 @@ module AccountRestriction = struct
   let of_deny () = Deny
 
   let jsont =
-    let open Jsont.Object in
     let regex = Case.map "regex" RegexAccountRestriction.jsont ~dec:of_regex in
     let deny = Case.map "deny" Jsont.ignore ~dec:of_deny in
     let enc_case = function
@@ -1176,7 +1144,6 @@ module ExchangeWireAccount = struct
     let master_sig v = v.master_sig in
     let bank_label v = v.bank_label in
     let priority v = v.priority in
-    let open Jsont.Object in
     map ~kind:"ExchangeWireAccount" make
     |> mem "payto_uri" Jsont.string ~enc:payto_uri
     |> opt_mem "conversion_url" Jsont.string ~enc:conversion_url
@@ -1204,7 +1171,6 @@ module ExtensionManifest = struct
     let critical v = v.critical in
     let version v = v.version in
     let config v = v.config in
-    let open Jsont.Object in
     map ~kind:"ExtensionManifest" make
     |> mem "critical" Jsont.bool ~enc:critical
     |> mem "version" Jsont.string ~enc:version
@@ -1338,8 +1304,6 @@ module ExchangeKeysResponse = struct
     let signkeys v = v.signkeys in
     let extensions v = v.extensions in
     let extensions_sig v = v.extensions_sig in
-
-    let open Jsont.Object in
     map ~kind:"ExchangeKeysResponse" make
     |> mem "version" Jsont.string ~enc:version
     |> mem "base_url" Jsont.string ~enc:base_url