diff --git a/include/maxscale/json_api.h b/include/maxscale/json_api.h
deleted file mode 100644
index 0553b8606..000000000
--- a/include/maxscale/json_api.h
+++ /dev/null
@@ -1,133 +0,0 @@
-/*
- * Copyright (c) 2018 MariaDB Corporation Ab
- *
- * Use of this software is governed by the Business Source License included
- * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
- *
- * Change Date: 2022-01-01
- *
- * On the date above, in accordance with the Business Source License, use
- * of this software will be governed by version 2 or later of the General
- * Public License.
- */
-#pragma once
-
-/**
- * @file Helper functions for creating JSON API conforming objects
- *
- * @see http://jsonapi.org/format/
- */
-
-#include <maxscale/cdefs.h>
-#include <maxbase/jansson.h>
-
-MXS_BEGIN_DECLS
-
-/** Resource endpoints */
-#define MXS_JSON_API_SERVERS     "/servers/"
-#define MXS_JSON_API_SERVICES    "/services/"
-#define MXS_JSON_API_FILTERS     "/filters/"
-#define MXS_JSON_API_MONITORS    "/monitors/"
-#define MXS_JSON_API_SESSIONS    "/sessions/"
-#define MXS_JSON_API_MAXSCALE    "/maxscale/"
-#define MXS_JSON_API_THREADS     "/maxscale/threads/"
-#define MXS_JSON_API_LOGS        "/maxscale/logs/"
-#define MXS_JSON_API_TASKS       "/maxscale/tasks/"
-#define MXS_JSON_API_MODULES     "/maxscale/modules/"
-#define MXS_JSON_API_QC_STATS    "/maxscale/qc_stats/"
-#define MXS_JSON_API_QC          "/maxscale/query_classifier/"
-#define MXS_JSON_API_QC_CLASSIFY "/maxscale/query_classifier/classify"
-#define MXS_JSON_API_USERS       "/users/"
-
-/**
- * @brief Create a JSON object
- *
- * @param host Hostname of this server
- * @param self Endpoint of this resource
- * @param data The JSON data, either an array or an object, stored in
- *             the `data` field of the returned object
- *
- * @return A valid top-level JSON API object
- */
-json_t* mxs_json_resource(const char* host, const char* self, json_t* data);
-
-
-/**
- * @brief Create a JSON metadata object
- *
- * This should be used to transport non-standard data to the client.
- *
- * @param host Hostname of this server
- * @param self Endpoint of this resource
- * @param data The JSON data, either an array or an object, stored in
- *             the `meta` field of the returned object
- *
- * @return A valid top-level JSON API object
- */
-json_t* mxs_json_metadata(const char* host, const char* self, json_t* data);
-
-/**
- * @brief Create an empty relationship object
- *
- * @param host Hostname of this server
- * @param endpoint The endpoint for the resource's collection
- *
- * @return New relationship object
- */
-json_t* mxs_json_relationship(const char* host, const char* endpoint);
-
-/**
- * @brief Add an item to a relationship object
- *
- * @param rel  Relationship created with mxs_json_relationship
- * @param id   The resource identifier
- * @param type The resource type
- */
-void mxs_json_add_relation(json_t* rel, const char* id, const char* type);
-
-/**
- * @brief Create self link object
- *
- * The self link points to the object itself.
- *
- * @param host Hostname of this server
- * @param path Base path to the resource collection
- * @param id   The identified of this resource
- *
- * @return New self link object
- */
-json_t* mxs_json_self_link(const char* host, const char* path, const char* id);
-
-/**
- * @brief Return value at provided JSON Pointer
- *
- * @param json     JSON object
- * @param json_ptr JSON Pointer to object
- *
- * @return Pointed value or NULL if no value is found
- */
-json_t* mxs_json_pointer(json_t* json, const char* json_ptr);
-
-
-/**
- * @brief Return a JSON formatted error
- *
- * @param format Format string
- * @param ...    Variable argument list
- *
- * @return The error as JSON
- */
-json_t* mxs_json_error(const char* format, ...);
-
-/**
- * @brief Append error to existing JSON object.
- *
- * @param object Existing json error object, or NULL.
- * @param format Format string
- * @param ...    Variable argument list
- *
- * @return The error added to 'errors' array of the JSON object.
- */
-json_t* mxs_json_error_append(json_t* object, const char* format, ...) mxb_attribute((format (printf, 2, 3)));
-
-MXS_END_DECLS
diff --git a/server/core/adminusers.cc b/server/core/adminusers.cc
index 6f2488b6f..28056b00c 100644
--- a/server/core/adminusers.cc
+++ b/server/core/adminusers.cc
@@ -26,7 +26,7 @@
 #include <maxscale/users.h>
 #include <maxscale/adminusers.h>
 #include <maxscale/paths.h>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 
 /**
  * @file adminusers.c - Administration user account management
diff --git a/server/core/config.cc b/server/core/config.cc
index b25367433..45be52272 100644
--- a/server/core/config.cc
+++ b/server/core/config.cc
@@ -46,7 +46,7 @@
 #include <maxscale/clock.h>
 #include <maxscale/housekeeper.h>
 #include <maxscale/http.hh>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/limits.h>
 #include <maxscale/maxscale.h>
 #include <maxscale/maxadmin.h>
diff --git a/server/core/config_runtime.cc b/server/core/config_runtime.cc
index 77b4b72ec..9d5df5af9 100644
--- a/server/core/config_runtime.cc
+++ b/server/core/config_runtime.cc
@@ -29,7 +29,7 @@
 #include <maxbase/atomic.h>
 #include <maxscale/clock.h>
 #include <maxscale/jansson.hh>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/paths.h>
 #include <maxscale/router.hh>
 #include <maxscale/users.h>
@@ -50,23 +50,31 @@ using maxscale::Monitor;
 static std::mutex crt_lock;
 
 #define RUNTIME_ERRMSG_BUFSIZE 512
-thread_local char runtime_errmsg[RUNTIME_ERRMSG_BUFSIZE];
+thread_local std::vector<std::string> runtime_errmsg;
 
 typedef std::function<bool (const std::string&, const std::string&)> JsonValidator;
 typedef std::pair<const char*, JsonValidator>                        Relationship;
 
 void config_runtime_error(const char* fmt, ...)
 {
+    char errmsg[RUNTIME_ERRMSG_BUFSIZE];
     va_list list;
     va_start(list, fmt);
-    vsnprintf(runtime_errmsg, sizeof(runtime_errmsg), fmt, list);
+    vsnprintf(errmsg, sizeof(errmsg), fmt, list);
     va_end(list);
+    runtime_errmsg.push_back(errmsg);
 }
 
 static std::string runtime_get_error()
 {
-    std::string rval(runtime_errmsg);
-    runtime_errmsg[0] = '\0';
+    std::string rval;
+
+    if (!runtime_errmsg.empty())
+    {
+        rval = runtime_errmsg.back();
+        runtime_errmsg.clear();
+    }
+
     return rval;
 }
 
@@ -2779,11 +2787,11 @@ bool runtime_create_listener_from_json(Service* service, json_t* json)
 json_t* runtime_get_json_error()
 {
     json_t* obj = NULL;
-    std::string errmsg = runtime_get_error();
 
-    if (errmsg.length())
+    if (!runtime_errmsg.empty())
     {
-        obj = mxs_json_error(errmsg.c_str());
+        obj = mxs_json_error(runtime_errmsg);
+        runtime_errmsg.clear();
     }
 
     return obj;
diff --git a/server/core/filter.cc b/server/core/filter.cc
index 9fb5304fe..e394c7582 100644
--- a/server/core/filter.cc
+++ b/server/core/filter.cc
@@ -35,7 +35,7 @@
 #include <maxscale/session.hh>
 #include <maxscale/service.hh>
 #include <maxscale/filter.hh>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 
 #include "internal/config.hh"
 #include "internal/modules.hh"
diff --git a/server/core/housekeeper.cc b/server/core/housekeeper.cc
index 9742463a4..56dd71eab 100644
--- a/server/core/housekeeper.cc
+++ b/server/core/housekeeper.cc
@@ -25,7 +25,7 @@
 #include <maxscale/clock.h>
 #include <maxscale/config.hh>
 #include <maxscale/housekeeper.h>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/query_classifier.hh>
 
 /**
diff --git a/server/core/json_api.cc b/server/core/json_api.cc
index f876869b1..f6f3c2d2b 100644
--- a/server/core/json_api.cc
+++ b/server/core/json_api.cc
@@ -11,7 +11,7 @@
  * Public License.
  */
 
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 
 #include <string>
 
@@ -207,6 +207,24 @@ json_t* mxs_json_error(const char* format, ...)
     return json_error(message);
 }
 
+json_t* mxs_json_error(const std::vector<std::string>& errors)
+{
+    json_t* rval = nullptr;
+
+    if (!errors.empty())
+    {
+        auto it = errors.begin();
+        rval = json_error(it->c_str());
+
+        for (it = std::next(it); it != errors.end(); ++it)
+        {
+            rval = mxs_json_error_append(rval, it->c_str());
+        }
+    }
+
+    return rval;
+}
+
 static json_t* json_error_append(json_t* obj, const char* message)
 {
     json_t* err = json_error_detail(message);
diff --git a/server/core/load_utils.cc b/server/core/load_utils.cc
index 7cc65536f..607849d9a 100644
--- a/server/core/load_utils.cc
+++ b/server/core/load_utils.cc
@@ -28,7 +28,7 @@
 #include <maxscale/version.h>
 #include <maxscale/paths.h>
 #include <maxscale/alloc.h>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/modulecmd.hh>
 #include <maxscale/protocol.hh>
 #include <maxscale/router.hh>
diff --git a/server/core/log.cc b/server/core/log.cc
index 2bfddf4c0..246933b75 100644
--- a/server/core/log.cc
+++ b/server/core/log.cc
@@ -23,7 +23,7 @@
 #include <maxbase/logger.hh>
 
 #include <maxscale/config.hh>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/session.hh>
 
 namespace
diff --git a/server/core/monitor.cc b/server/core/monitor.cc
index 25a04d697..b9cbab8cf 100644
--- a/server/core/monitor.cc
+++ b/server/core/monitor.cc
@@ -32,7 +32,7 @@
 #include <maxscale/alloc.h>
 #include <maxbase/atomic.hh>
 #include <maxscale/clock.h>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/mariadb.hh>
 #include <maxscale/mysql_utils.hh>
 #include <maxscale/paths.h>
@@ -40,7 +40,7 @@
 #include <maxscale/routingworker.hh>
 #include <maxscale/secrets.h>
 #include <maxscale/utils.hh>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <mysqld_error.h>
 
 #include "internal/config.hh"
diff --git a/server/core/query_classifier.cc b/server/core/query_classifier.cc
index e9fec8d70..05dab676a 100644
--- a/server/core/query_classifier.cc
+++ b/server/core/query_classifier.cc
@@ -21,7 +21,7 @@
 #include <maxbase/atomic.h>
 #include <maxbase/format.hh>
 #include <maxscale/config.hh>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/modutil.hh>
 #include <maxscale/pcre2.h>
 #include <maxscale/utils.h>
diff --git a/server/core/resource.cc b/server/core/resource.cc
index 8dd5fd638..1b67c23bd 100644
--- a/server/core/resource.cc
+++ b/server/core/resource.cc
@@ -21,7 +21,7 @@
 #include <maxscale/housekeeper.h>
 #include <maxscale/http.hh>
 #include <maxscale/jansson.hh>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/modulecmd.hh>
 #include <maxscale/routingworker.hh>
 
diff --git a/server/core/routingworker.cc b/server/core/routingworker.cc
index d6a59e091..11af2d5e2 100644
--- a/server/core/routingworker.cc
+++ b/server/core/routingworker.cc
@@ -30,7 +30,7 @@
 #include <maxscale/config.hh>
 #include <maxscale/clock.h>
 #include <maxscale/limits.h>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/utils.hh>
 #include <maxscale/statistics.hh>
 
diff --git a/server/core/server.cc b/server/core/server.cc
index c87e8a63f..911055c68 100644
--- a/server/core/server.cc
+++ b/server/core/server.cc
@@ -38,7 +38,7 @@
 #include <maxscale/alloc.h>
 #include <maxscale/paths.h>
 #include <maxscale/utils.h>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/clock.h>
 #include <maxscale/http.hh>
 #include <maxscale/maxscale.h>
diff --git a/server/core/service.cc b/server/core/service.cc
index 885ca561a..67a4b7461 100644
--- a/server/core/service.cc
+++ b/server/core/service.cc
@@ -51,7 +51,7 @@
 #include <maxscale/utils.h>
 #include <maxscale/utils.hh>
 #include <maxscale/version.h>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/routingworker.hh>
 #include <maxscale/routingworker.hh>
 
diff --git a/server/core/session.cc b/server/core/session.cc
index 8eb7235eb..4332da5bf 100644
--- a/server/core/session.cc
+++ b/server/core/session.cc
@@ -31,7 +31,7 @@
 #include <maxscale/clock.h>
 #include <maxscale/dcb.hh>
 #include <maxscale/housekeeper.h>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/modutil.hh>
 #include <maxscale/poll.hh>
 #include <maxscale/router.hh>
diff --git a/server/core/test/test_json.cc b/server/core/test/test_json.cc
index 65064a4cc..5c6c8f87a 100644
--- a/server/core/test/test_json.cc
+++ b/server/core/test/test_json.cc
@@ -16,7 +16,7 @@
 #include <string>
 
 #include <maxscale/jansson.hh>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 
 using std::string;
 
diff --git a/server/core/test/test_modulecmd.cc b/server/core/test/test_modulecmd.cc
index c471ce699..3f687c33e 100644
--- a/server/core/test/test_modulecmd.cc
+++ b/server/core/test/test_modulecmd.cc
@@ -21,7 +21,7 @@
 #include <maxscale/paths.h>
 #include <maxscale/modulecmd.hh>
 #include <maxscale/session.hh>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 
 #include "../internal/monitor.hh"
 
diff --git a/server/modules/filter/masking/maskingfilter.cc b/server/modules/filter/masking/maskingfilter.cc
index 55eee86df..6b005e6b8 100644
--- a/server/modules/filter/masking/maskingfilter.cc
+++ b/server/modules/filter/masking/maskingfilter.cc
@@ -14,7 +14,7 @@
 #define MXS_MODULE_NAME "masking"
 #include "maskingfilter.hh"
 
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/modulecmd.hh>
 #include <maxscale/paths.h>
 #include <maxscale/utils.h>
diff --git a/server/modules/filter/masking/maskingrules.cc b/server/modules/filter/masking/maskingrules.cc
index d584624b5..c36dc2f85 100644
--- a/server/modules/filter/masking/maskingrules.cc
+++ b/server/modules/filter/masking/maskingrules.cc
@@ -22,7 +22,7 @@
 #include <maxscale/mysql_utils.hh>
 #include <maxscale/pcre2.hh>
 #include <maxscale/utils.hh>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 
 using std::auto_ptr;
 using std::string;
diff --git a/server/modules/filter/qlafilter/qlafilter.cc b/server/modules/filter/qlafilter/qlafilter.cc
index b0069762c..a8fdaea7d 100644
--- a/server/modules/filter/qlafilter/qlafilter.cc
+++ b/server/modules/filter/qlafilter/qlafilter.cc
@@ -45,7 +45,7 @@
 #include <maxscale/service.hh>
 #include <maxscale/utils.h>
 #include <maxscale/modulecmd.hh>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 
 using std::string;
 
@@ -100,7 +100,6 @@ void print_string_replace_newlines(const char* sql_string, size_t sql_str_len,
                                    const char* rep_newline, std::stringstream* output);
 
 bool check_replace_file(const string& filename, FILE** ppFile);
-
 }
 
 QlaInstance::QlaInstance(const string& name, MXS_CONFIG_PARAMETER* params)
diff --git a/server/modules/filter/throttlefilter/throttlefilter.cc b/server/modules/filter/throttlefilter/throttlefilter.cc
index fbab596ea..05059a4c2 100644
--- a/server/modules/filter/throttlefilter/throttlefilter.cc
+++ b/server/modules/filter/throttlefilter/throttlefilter.cc
@@ -8,7 +8,7 @@
 
 #include <maxscale/ccdefs.hh>
 #include <maxscale/utils.h>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include <maxscale/jansson.hh>
 
 #include "throttlefilter.hh"
diff --git a/server/modules/monitor/clustrixmon/clustrixmonitor.cc b/server/modules/monitor/clustrixmon/clustrixmonitor.cc
index 5584feffe..37558780a 100644
--- a/server/modules/monitor/clustrixmon/clustrixmonitor.cc
+++ b/server/modules/monitor/clustrixmon/clustrixmonitor.cc
@@ -14,7 +14,7 @@
 #include "clustrixmonitor.hh"
 #include <algorithm>
 #include <set>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 #include "../../../core/internal/config_runtime.hh"
 #include "../../../core/internal/service.hh"
 
diff --git a/server/modules/monitor/mariadbmon/mariadbmon_common.hh b/server/modules/monitor/mariadbmon/mariadbmon_common.hh
index cf815649f..34e0bbaf9 100644
--- a/server/modules/monitor/mariadbmon/mariadbmon_common.hh
+++ b/server/modules/monitor/mariadbmon/mariadbmon_common.hh
@@ -21,7 +21,7 @@
 #include <maxscale/ccdefs.hh>
 
 #include <string>
-#include <maxscale/json_api.h>
+#include <maxscale/json_api.hh>
 
 /** Utility macros for printing both MXS_ERROR and json error */
 #define PRINT_MXS_JSON_ERROR(err_out, format, ...) \