diff --git a/src/handler.ml b/src/handler.ml
index 17cc203f..55ed8336 100644
--- a/src/handler.ml
+++ b/src/handler.ml
@@ -88,3 +88,17 @@ let management_signkey_revoke req exchange_pub server _env =
     Ok ""
   in
   respond_with_res res req
+
+let management_auditors_jsont = AuditorSetupMessage.jsont
+
+let management_auditors req server _env =
+  let open Syntax in
+  let open Management in
+  let db_conn = Vif.Server.device Devices.db_connection server in
+  let res =
+    let* v = Vif.Request.of_json req |> unwrap_err_msg in
+    let* () = verify_auditor_add_sig v in
+    let* () = update_auditor ~db_conn v in
+    Ok ""
+  in
+  respond_with_res res req
diff --git a/src/management.ml b/src/management.ml
index de55ae39..63480e6a 100644
--- a/src/management.ml
+++ b/src/management.ml
@@ -182,15 +182,9 @@ let check_master_signatures_update ~db_conn ~sm_denom =
         match opt with None -> error | Some v -> Ok v
       in
       let check = function false -> error | true -> Ok () in
-      (* TODO time *)
-      let timestamp_equal a b =
-        let timestamp_to_int64 = function
-          | None -> None
-          | Some v -> v |> Ptime.to_float_s |> Int64.of_float |> Option.some
-        in
-        timestamp_to_int64 a = timestamp_to_int64 b
+      let* () =
+        check (Timestamp.compare valid_from denom.stamp_start = Some 0)
       in
-      let* () = check (timestamp_equal valid_from denom.stamp_start) in
       let* () = check (coin = denom.value) in
       let* () = check (fee_refund = denom.fee_refund) in
       let* () = check (age_mask = denom.age_mask) in
@@ -243,3 +237,43 @@ let update_signkey_revocation ~db_conn ~sm_signkey exchange_pub
     |> unwrap_err_caqti
   in
   Ok ()
+
+let verify_auditor_add_sig
+    AuditorSetupMessage.
+      { auditor_url; auditor_name= _; auditor_pub; master_sig; validity_start }
+    =
+  let open Bin_sig.MasterAddAuditor in
+  verify ~key:Config.Exchange.master_public_key master_sig
+    {
+      start_date= validity_start;
+      auditor_pub;
+      h_auditor_url= Bin_type.Hash_64_cstr.hash auditor_url;
+    }
+
+(* todo: there is something about use of monotonic time + protection against replay attack that I don't understand *)
+let update_auditor ~db_conn
+    AuditorSetupMessage.
+      { auditor_url; auditor_name; auditor_pub; master_sig= _; validity_start }
+    =
+  let open Syntax in
+  let* last_date_opt =
+    Pg.lookup_auditor_timestamp db_conn auditor_pub |> unwrap_err_caqti
+  in
+  match last_date_opt with
+  | None ->
+      let+ () =
+        Pg.insert_auditor db_conn ~auditor_pub ~auditor_url ~auditor_name
+          ~start_date:validity_start
+        |> unwrap_err_caqti
+      in
+      ()
+  | Some last_date ->
+      let cmp = Timestamp.compare last_date validity_start |> Option.get in
+      if cmp > 0 then Error "more recent management auditor already present"
+      else
+        let+ () =
+          Pg.update_auditor db_conn ~auditor_pub ~auditor_url ~auditor_name
+            ~enabled:true ~change_date:validity_start
+          |> unwrap_err_caqti
+        in
+        ()
diff --git a/src/mte.ml b/src/mte.ml
index f6265ca4..530826a2 100644
--- a/src/mte.ml
+++ b/src/mte.ml
@@ -43,6 +43,8 @@ let routes =
       (v "management" / "signkeys" /% string `Path / "revoke")
       management_signkey_revoke_jsont
     --> management_signkey_revoke;
+    post (v "management" / "auditors") management_auditors_jsont
+    --> management_auditors;
   ]
 
 let () =
diff --git a/src/pg.ml b/src/pg.ml
index af06fc11..a02efab9 100644
--- a/src/pg.ml
+++ b/src/pg.ml
@@ -28,9 +28,9 @@ module Caqti_type = struct
   let ptime : Ptime.t option t = Timestamp.caqti
   let time = Timestamp.caqti
   let age_mask : int t = Caqti_type.int
-  let rsa_public = RsaPublicKey.caqti
-  let eddsa_public = EddsaPublicKey.caqti
-  let eddsa_signature = EddsaSignature.caqti
+  let rsa_pub = RsaPublicKey.caqti
+  let eddsa_pub = EddsaPublicKey.caqti
+  let eddsa_sig = EddsaSignature.caqti
 
   include struct
     (* alias for hash *)
@@ -68,7 +68,7 @@ let preflight =
 
 let lookup_signing_key =
   let lookup_signing_key =
-    Caqti_type.(eddsa_public ->? t3 time time time)
+    Caqti_type.(eddsa_pub ->? t3 time time time)
       "SELECT valid_from, expire_sign, expire_legal FROM exchange_sign_keys \
        WHERE exchange_pub=$1"
   in
@@ -78,7 +78,7 @@ let lookup_signing_key =
 let activate_signing_key =
   let insert_signkey =
     let master_sig = Bin_sig.ExchangeSigningKeyValidity.caqti in
-    Caqti_type.(t5 eddsa_public time time time master_sig ->. unit)
+    Caqti_type.(t5 eddsa_pub time time time master_sig ->. unit)
       "INSERT INTO exchange_sign_keys (exchange_pub, valid_from, expire_sign, \
        expire_legal, master_sig) VALUES ($1, $2, $3, $4, $5)"
   in
@@ -114,8 +114,8 @@ let add_denomination_key =
   let denomination_insert =
     let master_sig = Bin_sig.DenominationKeyValidity.caqti in
     Caqti_type.(
-      t12 denomination_hash rsa_public master_sig time time time time amount
-        amount amount amount (t2 amount age_mask)
+      t12 denomination_hash rsa_pub master_sig time time time time amount amount
+        amount amount (t2 amount age_mask)
       ->. unit)
       "INSERT INTO denominations (denom_pub_hash, denom_pub, master_sig, \
        valid_from, expire_withdraw, expire_deposit, expire_legal, coin, \
@@ -173,9 +173,48 @@ let insert_denomination_revocation =
 let insert_signkey_revocation =
   let signkey_revocation_insert =
     let master_sig = Bin_sig.MasterSigningKeyRevocation.caqti in
-    Caqti_type.(t2 eddsa_public master_sig ->. unit)
+    Caqti_type.(t2 eddsa_pub master_sig ->. unit)
       "INSERT INTO signkey_revocations (esk_serial, master_sig) SELECT \
        esk_serial, $2 FROM exchange_sign_keys WHERE exchange_pub=$1"
   in
   fun (module Conn : CONN) exchange_pub master_sig ->
     Conn.exec signkey_revocation_insert (exchange_pub, master_sig)
+
+let lookup_auditor_timestamp =
+  let lookup_auditor_timestamp =
+    Caqti_type.(eddsa_pub ->? time)
+      "lookup_auditor_timestamp SELECT last_change FROM auditors WHERE \
+       auditor_pub=$1"
+  in
+  fun (module Conn : CONN) auditor_pub ->
+    Conn.find_opt lookup_auditor_timestamp auditor_pub
+
+let insert_auditor =
+  let insert_auditor =
+    Caqti_type.(t4 eddsa_pub string string time ->. unit)
+      "INSERT INTO auditors (auditor_pub, auditor_name, auditor_url, \
+       is_active, last_change) VALUES ($1, $2, $3, true, $4)"
+  in
+  fun (module Conn : CONN)
+    ~auditor_pub
+    ~auditor_url
+    ~auditor_name
+    ~start_date
+  ->
+    Conn.exec insert_auditor (auditor_pub, auditor_name, auditor_url, start_date)
+
+let update_auditor =
+  let update_auditor =
+    Caqti_type.(t5 eddsa_pub string string bool time ->. unit)
+      "UPDATE auditors SET auditor_url=$2, auditor_name=$3, is_active=$4, \
+       last_change=$5 WHERE auditor_pub=$1"
+  in
+  fun (module Conn : CONN)
+    ~auditor_pub
+    ~auditor_url
+    ~auditor_name
+    ~change_date
+    ~enabled
+  ->
+    Conn.exec update_auditor
+      (auditor_pub, auditor_url, auditor_name, enabled, change_date)
diff --git a/src/timestamp.ml b/src/timestamp.ml
index 710ac992..d01bf83c 100644
--- a/src/timestamp.ml
+++ b/src/timestamp.ml
@@ -67,3 +67,13 @@ let caqti : Ptime.t option Caqti_type.t =
   let encode v = Ok (encode_int64 v) in
   let decode v = Ok (decode_int64 v) in
   Caqti_type.custom ~encode ~decode Caqti_type.int64
+
+let compare a b =
+  match (a, b) with
+  | None, None -> Some 0
+  | None, _ | _, None -> None
+  | Some a, Some b ->
+      let a = ptime_to_int64 a in
+      let b = ptime_to_int64 b in
+      let c = Int64.compare a b in
+      Some c
diff --git a/src/timestamp.mli b/src/timestamp.mli
index ae81b3a3..d5d10c5b 100644
--- a/src/timestamp.mli
+++ b/src/timestamp.mli
@@ -1,6 +1,8 @@
 (* TODO time
    uhuh!
-   need to be int64 for binary/pg round trip *)
+   need to be int64 for binary/pg round trip
+
+   really need to fix this module *)
 
 type t = Ptime.t option
 type span = Ptime.Span.t option
@@ -8,6 +10,7 @@ type span = Ptime.Span.t option
 val diff : t -> t -> span
 val add_span_exn : t -> span -> t
 val of_span_exn : span -> t
+val compare : t -> t -> int option
 
 (* - *)
 val jsont : t Jsont.t