diff --git a/src/exchange-lib/Makefile.am b/src/exchange-lib/Makefile.am
index dee17b2e2..00815db31 100644
--- a/src/exchange-lib/Makefile.am
+++ b/src/exchange-lib/Makefile.am
@@ -68,7 +68,8 @@ libtalertesting_la_SOURCES = \
   testing_api_trait_string.c \
   testing_api_trait_key_peer.c \
   testing_api_trait_wtid.c \
-  testing_api_trait_amount.c
+  testing_api_trait_amount.c \
+  testing_api_trait_hash.c
 
 libtalertesting_la_LIBADD = \
   $(top_builddir)/src/json/libtalerjson.la \
diff --git a/src/exchange-lib/testing_api_trait_amount.c b/src/exchange-lib/testing_api_trait_amount.c
new file mode 100644
index 000000000..a9c5b3bc2
--- /dev/null
+++ b/src/exchange-lib/testing_api_trait_amount.c
@@ -0,0 +1,71 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2018 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as
+  published by the Free Software Foundation; either version 3,
+  or (at your option) any later version.
+
+  TALER is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public
+  License along with TALER; see the file COPYING.  If not, see
+  <http://www.gnu.org/licenses/>
+*/
+
+/**
+ * @file exchange-lib/testing_api_trait_amount.c
+ * @brief offer amounts as traits
+ * @author Marcello Stanisci
+ */
+
+#include "platform.h"
+#include "taler_json_lib.h"
+#include <gnunet/gnunet_curl_lib.h>
+#include "exchange_api_handle.h"
+#include "taler_signatures.h"
+#include "taler_testing_lib.h"
+
+#define TALER_TESTING_TRAIT_AMOUNT "amount"
+
+/**
+ * Obtain an amount from a @a cmd.
+ *
+ * @param cmd command to extract trait from
+ * @param selector which amount to pick if @a cmd has multiple
+ *        on offer
+ * @param amount[out] set to the amount
+ * @return #GNUNET_OK on success
+ */
+int
+TALER_TESTING_get_trait_amount_obj (
+  const struct TALER_TESTING_Command *cmd,
+  unsigned int index,
+  struct TALER_Amount **amount)
+{
+  return cmd->traits (cmd->cls,
+                      (void **) amount,
+                      TALER_TESTING_TRAIT_AMOUNT,
+                      index);
+}
+
+struct TALER_TESTING_Trait
+TALER_TESTING_make_trait_amount_obj (
+  unsigned int index,
+  const struct TALER_Amount *amount)
+{
+  struct TALER_TESTING_Trait ret = {
+    .index = index,
+    .trait_name = TALER_TESTING_TRAIT_AMOUNT,
+    .ptr = (const void *) amount
+  };
+
+  return ret;
+}
+
+
+/* end of testing_api_trait_amount.c */
diff --git a/src/exchange-lib/testing_api_trait_hash.c b/src/exchange-lib/testing_api_trait_hash.c
new file mode 100644
index 000000000..5a8ed7dc3
--- /dev/null
+++ b/src/exchange-lib/testing_api_trait_hash.c
@@ -0,0 +1,74 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2018 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published
+  by the Free Software Foundation; either version 3, or (at your
+  option) any later version.
+
+  TALER is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public
+  License along with TALER; see the file COPYING.  If not, see
+  <http://www.gnu.org/licenses/>
+*/
+
+/**
+ * @file exchange-lib/testing_api_trait_hash.c
+ * @brief traits to offer hash codes.
+ * @author Marcello Stanisci
+ */
+#include "platform.h"
+#include "taler_json_lib.h"
+#include <gnunet/gnunet_curl_lib.h>
+#include "exchange_api_handle.h"
+#include "taler_signatures.h"
+#include "taler_testing_lib.h"
+
+#define TALER_TESTING_TRAIT_HASH "hash"
+
+/**
+ * Obtain a hash code from @a cmd.
+ *
+ * @param cmd command to extract trait from
+ * @param index which hash code to pick if @a cmd has multiple on
+ *        offer
+ * @param wtid[out] set to the wanted hash code.
+ * @return #GNUNET_OK on success
+ */
+int
+TALER_TESTING_get_trait_hash
+  (const struct TALER_TESTING_Command *cmd,
+   unsigned int index,
+   struct GNUNET_HashCode **hash)
+{
+  return cmd->traits (cmd->cls,
+                      (void **) hash,
+                      TALER_TESTING_TRAIT_HASH,
+                      index);
+}
+
+/**
+ * @param index associate the hash code with this index
+ * @param hash which hash code should be returned
+ *
+ * @return the trait, to be put in the traits array of the command
+ */
+struct TALER_TESTING_Trait
+TALER_TESTING_make_trait_hash
+  (unsigned int index,
+   struct GNUNET_HashCode *hash)
+{
+  struct TALER_TESTING_Trait ret = {
+    .index = index,
+    .trait_name = TALER_TESTING_TRAIT_HASH,
+    .ptr = (const void *) hash
+  };
+  return ret;
+}
+
+/* end of testing_api_trait_hash.c */
diff --git a/src/include/taler_testing_lib.h b/src/include/taler_testing_lib.h
index f7af83311..34f3217ff 100644
--- a/src/include/taler_testing_lib.h
+++ b/src/include/taler_testing_lib.h
@@ -1332,4 +1332,30 @@ TALER_TESTING_make_trait_amount_obj (
   const struct TALER_Amount *amount);
 
 
+/**
+ * Obtain a hash code from @a cmd.
+ *
+ * @param cmd command to extract trait from
+ * @param index which hash code to pick if @a cmd has multiple on
+ *        offer
+ * @param wtid[out] set to the wanted hash code.
+ * @return #GNUNET_OK on success
+ */
+int
+TALER_TESTING_get_trait_hash
+  (const struct TALER_TESTING_Command *cmd,
+   unsigned int index,
+   struct GNUNET_HashCode **hash);
+
+/**
+ * @param index associate the hash code with this index
+ * @param hash which hash code should be returned
+ *
+ * @return the trait, to be put in the traits array of the command
+ */
+struct TALER_TESTING_Trait
+TALER_TESTING_make_trait_hash
+  (unsigned int index,
+   struct GNUNET_HashCode *hash);
+
 #endif