diff --git a/backend/src/uxbox/config.clj b/backend/src/uxbox/config.clj
index 795c563cb..803b61261 100644
--- a/backend/src/uxbox/config.clj
+++ b/backend/src/uxbox/config.clj
@@ -6,15 +6,15 @@
 
 (ns uxbox.config
   "A configuration management."
-  (:require [clojure.java.io :as io]
-            [clojure.tools.logging :as log]
-            [clojure.edn :as edn]
-            [cuerdas.core :as str]
-            [buddy.core.hash :as hash]
-            [environ.core :refer [env]]
-            [mount.core :refer [defstate]]
-            [uxbox.util.exceptions :as ex]
-            [uxbox.util.data :refer [deep-merge]]))
+  (:require
+   [clojure.java.io :as io]
+   [clojure.tools.logging :as log]
+   [clojure.edn :as edn]
+   [cuerdas.core :as str]
+   [buddy.core.hash :as hash]
+   [environ.core :refer [env]]
+   [mount.core :refer [defstate]]
+   [uxbox.common.exceptions :as ex]))
 
 ;; --- Configuration Reading & Loading
 
diff --git a/backend/src/uxbox/db.clj b/backend/src/uxbox/db.clj
index 84d92e026..04d09681a 100644
--- a/backend/src/uxbox/db.clj
+++ b/backend/src/uxbox/db.clj
@@ -10,10 +10,10 @@
    [lambdaisland.uri :refer [uri]]
    [mount.core :as mount :refer [defstate]]
    [promesa.core :as p]
+   [uxbox.common.exceptions :as ex]
    [uxbox.config :as cfg]
    [uxbox.core :refer [system]]
    [uxbox.util.data :as data]
-   [uxbox.util.exceptions :as ex]
    [uxbox.util.pgsql :as pg]
    [vertx.core :as vx])
   (:import io.vertx.core.buffer.Buffer))
diff --git a/backend/src/uxbox/emails.clj b/backend/src/uxbox/emails.clj
index 8a206eaf3..51d1c5436 100644
--- a/backend/src/uxbox/emails.clj
+++ b/backend/src/uxbox/emails.clj
@@ -10,12 +10,12 @@
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
    [uxbox.config :as cfg]
+   [uxbox.common.exceptions :as ex]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.media :as media]
-   [uxbox.util.exceptions :as ex]
    [uxbox.util.emails :as emails]
-   [uxbox.util.blob :as blob]
-   [uxbox.util.spec :as us]))
+   [uxbox.util.blob :as blob]))
 
 ;; --- Defaults
 
@@ -44,8 +44,8 @@
 (defn send!
   "Schedule the email for sending."
   [email context]
-  (s/assert fn? email)
-  (s/assert map? context)
+  (us/assert fn? email)
+  (us/assert map? context)
   (let [defaults {:from (:email-from cfg/config)
                   :reply-to (:email-reply-to cfg/config)}
         data (->> (merge defaults context)
diff --git a/backend/src/uxbox/http/interceptors.clj b/backend/src/uxbox/http/interceptors.clj
index 45a33aef3..eff7fb232 100644
--- a/backend/src/uxbox/http/interceptors.clj
+++ b/backend/src/uxbox/http/interceptors.clj
@@ -7,8 +7,8 @@
 (ns uxbox.http.interceptors
   (:require
    [vertx.web :as vw]
-   [uxbox.util.transit :as t]
-   [uxbox.util.exceptions :as ex])
+   [uxbox.common.exceptions :as ex]
+   [uxbox.util.transit :as t])
   (:import
    io.vertx.ext.web.RoutingContext
    io.vertx.ext.web.FileUpload
diff --git a/backend/src/uxbox/http/session.clj b/backend/src/uxbox/http/session.clj
index f85b12867..877138948 100644
--- a/backend/src/uxbox/http/session.clj
+++ b/backend/src/uxbox/http/session.clj
@@ -10,7 +10,6 @@
    [sieppari.context :as spx]
    [vertx.core :as vc]
    [uxbox.db :as db]
-   [uxbox.util.exceptions :as ex]
    [uxbox.util.uuid :as uuid]))
 
 ;; --- Main API
diff --git a/backend/src/uxbox/images.clj b/backend/src/uxbox/images.clj
index 6b2c7633a..540ab8a44 100644
--- a/backend/src/uxbox/images.clj
+++ b/backend/src/uxbox/images.clj
@@ -12,9 +12,9 @@
    [datoteka.core :as fs]
    [datoteka.proto :as pt]
    [datoteka.storages :as st]
-   [uxbox.media :as media]
-   [uxbox.util.data :refer (dissoc-in)]
-   [uxbox.util.spec :as us])
+   [uxbox.common.data :as d]
+   [uxbox.common.spec :as us]
+   [uxbox.media :as media])
   (:import
    java.io.ByteArrayInputStream
    java.io.InputStream
@@ -43,8 +43,8 @@
                 width 200
                 height 200}
            :as opts}]
-   (s/assert ::thumbnail-opts opts)
-   (s/assert fs/path? input)
+   (us/assert ::thumbnail-opts opts)
+   (us/assert fs/path? input)
    (let [tmp (fs/create-tempfile :suffix (str "." format))
          opr (doto (IMOperation.)
                (.addImage)
@@ -60,7 +60,7 @@
 
 (defn make-thumbnail
   [input {:keys [width height format quality] :as opts}]
-  (s/assert ::thumbnail-opts opts)
+  (us/assert ::thumbnail-opts opts)
   (let [[filename ext] (fs/split-ext (fs/name input))
         suffix (->> [width height quality format]
                     (interpose ".")
@@ -102,6 +102,6 @@
       entry
       (let [url (str (st/public-url storage value))]
         (-> entry
-            (dissoc-in src)
+            (d/dissoc-in src)
             (assoc-in dst url))))))
 
diff --git a/backend/src/uxbox/jobs/sendmail.clj b/backend/src/uxbox/jobs/sendmail.clj
index 75e82a864..6435133b5 100644
--- a/backend/src/uxbox/jobs/sendmail.clj
+++ b/backend/src/uxbox/jobs/sendmail.clj
@@ -12,11 +12,11 @@
    [promesa.core :as p]
    [uxbox.core :refer [system]]
    [postal.core :as postal]
+   [uxbox.common.exceptions :as ex]
    [uxbox.config :as cfg]
    [uxbox.db :as db]
    [uxbox.util.jobs :as uj]
    [uxbox.util.blob :as blob]
-   [uxbox.util.exceptions :as ex]
    [mount.core :as mount :refer [defstate]]))
 
 ;; TODO: implement low priority sending emails.
diff --git a/backend/src/uxbox/media_loader.clj b/backend/src/uxbox/media_loader.clj
index d111ba88c..896afa814 100644
--- a/backend/src/uxbox/media_loader.clj
+++ b/backend/src/uxbox/media_loader.clj
@@ -18,13 +18,13 @@
    [datoteka.storages :as st]
    [datoteka.core :as fs]
    [uxbox.config]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.http]
    [uxbox.migrations]
    [uxbox.media :as media]
    [uxbox.util.svg :as svg]
    [uxbox.util.transit :as t]
-   [uxbox.util.spec :as us]
    [uxbox.util.blob :as blob]
    [uxbox.util.uuid :as uuid]
    [uxbox.util.data :as data])
diff --git a/backend/src/uxbox/services/mutations.clj b/backend/src/uxbox/services/mutations.clj
index 6bfa98c50..3aba95007 100644
--- a/backend/src/uxbox/services/mutations.clj
+++ b/backend/src/uxbox/services/mutations.clj
@@ -6,8 +6,7 @@
 
 (ns uxbox.services.mutations
   (:require
-   [uxbox.util.dispatcher :as uds]
-   [uxbox.util.exceptions :as ex]))
+   [uxbox.util.dispatcher :as uds]))
 
 (uds/defservice handle
   {:dispatch-by ::type
diff --git a/backend/src/uxbox/services/mutations/auth.clj b/backend/src/uxbox/services/mutations/auth.clj
index fa26f75b0..9011dfc01 100644
--- a/backend/src/uxbox/services/mutations/auth.clj
+++ b/backend/src/uxbox/services/mutations/auth.clj
@@ -10,10 +10,10 @@
    [buddy.hashers :as hashers]
    [promesa.core :as p]
    [uxbox.config :as cfg]
+   [uxbox.common.exceptions :as ex]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
-   [uxbox.services.mutations :as sm]
-   [uxbox.util.spec :as us]
-   [uxbox.util.exceptions :as ex]))
+   [uxbox.services.mutations :as sm]))
 
 (def ^:private user-by-username-sql
   "select id, password
diff --git a/backend/src/uxbox/services/mutations/icons.clj b/backend/src/uxbox/services/mutations/icons.clj
index d9c306526..304d1b3f5 100644
--- a/backend/src/uxbox/services/mutations/icons.clj
+++ b/backend/src/uxbox/services/mutations/icons.clj
@@ -9,11 +9,11 @@
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
    [uxbox.db :as db]
+   [uxbox.common.spec :as us]
    [uxbox.services.mutations :as sm]
    [uxbox.services.util :as su]
    [uxbox.services.queries.icons :refer [decode-icon-row]]
    [uxbox.util.blob :as blob]
-   [uxbox.util.spec :as us]
    [uxbox.util.uuid :as uuid]))
 
 ;; --- Helpers & Specs
diff --git a/backend/src/uxbox/services/mutations/images.clj b/backend/src/uxbox/services/mutations/images.clj
index b4270e0b4..39c144a84 100644
--- a/backend/src/uxbox/services/mutations/images.clj
+++ b/backend/src/uxbox/services/mutations/images.clj
@@ -11,6 +11,8 @@
    [datoteka.storages :as ds]
    [promesa.core :as p]
    [promesa.exec :as px]
+   [uxbox.common.exceptions :as ex]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.media :as media]
    [uxbox.images :as images]
@@ -18,8 +20,6 @@
    [uxbox.services.util :as su]
    [uxbox.util.blob :as blob]
    [uxbox.util.data :as data]
-   [uxbox.util.exceptions :as ex]
-   [uxbox.util.spec :as us]
    [uxbox.util.uuid :as uuid]
    [vertx.core :as vc]))
 
@@ -117,7 +117,15 @@
 (def valid-image-types?
   #{"image/jpeg", "image/png", "image/webp"})
 
-(s/def ::file ::us/upload)
+(s/def :uxbox$upload/name ::us/string)
+(s/def :uxbox$upload/size ::us/integer)
+(s/def :uxbox$upload/mtype ::us/string)
+(s/def ::upload
+  (s/keys :req-un [:uxbox$upload/name
+                   :uxbox$upload/size
+                   :uxbox$upload/mtype]))
+
+(s/def ::file ::upload)
 (s/def ::width ::us/integer)
 (s/def ::height ::us/integer)
 (s/def ::mimetype valid-image-types?)
diff --git a/backend/src/uxbox/services/mutations/project_files.clj b/backend/src/uxbox/services/mutations/project_files.clj
index f2bfc6046..fb8283a87 100644
--- a/backend/src/uxbox/services/mutations/project_files.clj
+++ b/backend/src/uxbox/services/mutations/project_files.clj
@@ -9,11 +9,11 @@
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
    [uxbox.db :as db]
-   [uxbox.util.spec :as us]
+   [uxbox.common.exceptions :as ex]
+   [uxbox.common.spec :as us]
    [uxbox.services.mutations :as sm]
    [uxbox.services.mutations.projects :as proj]
    [uxbox.services.util :as su]
-   [uxbox.util.exceptions :as ex]
    [uxbox.util.blob :as blob]
    [uxbox.util.uuid :as uuid]))
 
diff --git a/backend/src/uxbox/services/mutations/project_pages.clj b/backend/src/uxbox/services/mutations/project_pages.clj
index 1df535578..52948a679 100644
--- a/backend/src/uxbox/services/mutations/project_pages.clj
+++ b/backend/src/uxbox/services/mutations/project_pages.clj
@@ -9,14 +9,14 @@
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
    [uxbox.common.pages :as cp]
+   [uxbox.common.exceptions :as ex]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.services.mutations :as sm]
    [uxbox.services.mutations.project-files :as files]
    [uxbox.services.queries.project-pages :refer [decode-row]]
    [uxbox.services.util :as su]
    [uxbox.util.blob :as blob]
-   [uxbox.util.exceptions :as ex]
-   [uxbox.util.spec :as us]
    [uxbox.util.sql :as sql]
    [uxbox.util.uuid :as uuid]
    [vertx.eventbus :as ve]))
diff --git a/backend/src/uxbox/services/mutations/projects.clj b/backend/src/uxbox/services/mutations/projects.clj
index 0b8392e15..c2ffd7742 100644
--- a/backend/src/uxbox/services/mutations/projects.clj
+++ b/backend/src/uxbox/services/mutations/projects.clj
@@ -9,11 +9,11 @@
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
    [uxbox.db :as db]
-   [uxbox.util.spec :as us]
+   [uxbox.common.exceptions :as ex]
+   [uxbox.common.spec :as us]
    [uxbox.services.mutations :as sm]
    [uxbox.services.util :as su]
    [uxbox.util.blob :as blob]
-   [uxbox.util.exceptions :as ex]
    [uxbox.util.uuid :as uuid]))
 
 ;; --- Helpers & Specs
diff --git a/backend/src/uxbox/services/mutations/user_attrs.clj b/backend/src/uxbox/services/mutations/user_attrs.clj
index 9d459ebb6..42c952025 100644
--- a/backend/src/uxbox/services/mutations/user_attrs.clj
+++ b/backend/src/uxbox/services/mutations/user_attrs.clj
@@ -9,11 +9,11 @@
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
    [uxbox.db :as db]
+   [uxbox.common.spec :as us]
    [uxbox.services.mutations :as sm]
    [uxbox.services.util :as su]
    [uxbox.services.queries.user-attrs :refer [decode-row]]
-   [uxbox.util.blob :as blob]
-   [uxbox.util.spec :as us]))
+   [uxbox.util.blob :as blob]))
 
 ;; --- Update
 
diff --git a/backend/src/uxbox/services/mutations/users.clj b/backend/src/uxbox/services/mutations/users.clj
index 308775ff9..95314f808 100644
--- a/backend/src/uxbox/services/mutations/users.clj
+++ b/backend/src/uxbox/services/mutations/users.clj
@@ -13,6 +13,8 @@
    [promesa.core :as p]
    [promesa.exec :as px]
    [uxbox.config :as cfg]
+   [uxbox.common.exceptions :as ex]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.emails :as emails]
    [uxbox.images :as images]
@@ -24,8 +26,6 @@
                                          strip-private-attrs
                                          resolve-thumbnail]]
    [uxbox.util.blob :as blob]
-   [uxbox.util.exceptions :as ex]
-   [uxbox.util.spec :as us]
    [uxbox.util.token :as token]
    [uxbox.util.uuid :as uuid]
    [vertx.core :as vc]))
@@ -125,7 +125,16 @@
 
 ;; --- Mutation: Update Photo
 
-(s/def ::file ::us/upload)
+
+(s/def :uxbox$upload/name ::us/string)
+(s/def :uxbox$upload/size ::us/integer)
+(s/def :uxbox$upload/mtype ::us/string)
+(s/def ::upload
+  (s/keys :req-un [:uxbox$upload/name
+                   :uxbox$upload/size
+                   :uxbox$upload/mtype]))
+
+(s/def ::file ::upload)
 (s/def ::update-profile-photo
   (s/keys :req-un [::user ::file]))
 
@@ -286,13 +295,13 @@
 
 ;; (defmethod core/query :validate-profile-password-recovery-token
 ;;   [{:keys [token]}]
-;;   (s/assert ::us/token token)
+;;   (us/assert ::us/token token)
 ;;   (with-open [conn (db/connection)]
 ;;     (recovery-token-exists? conn token)))
 
 ;; (defmethod core/novelty :request-profile-password-recovery
 ;;   [{:keys [username]}]
-;;   (s/assert ::us/username username)
+;;   (us/assert ::us/username username)
 ;;   (with-open [conn (db/connection)]
 ;;     (db/atomic conn
 ;;       (request-password-recovery conn username))))
@@ -302,7 +311,7 @@
 
 ;; (defmethod core/novelty :recover-profile-password
 ;;   [params]
-;;   (s/assert ::recover-password params)
+;;   (us/assert ::recover-password params)
 ;;   (with-open [conn (db/connection)]
 ;;     (db/apply-atomic conn recover-password params)))
 
diff --git a/backend/src/uxbox/services/queries/icons.clj b/backend/src/uxbox/services/queries/icons.clj
index eb7faecf1..36fdffa89 100644
--- a/backend/src/uxbox/services/queries/icons.clj
+++ b/backend/src/uxbox/services/queries/icons.clj
@@ -8,11 +8,11 @@
   (:require
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
+   [uxbox.common.exceptions :as ex]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.services.queries :as sq]
-   [uxbox.util.blob :as blob]
-   [uxbox.util.exceptions :as ex]
-   [uxbox.util.spec :as us]))
+   [uxbox.util.blob :as blob]))
 
 ;; --- Helpers & Specs
 
diff --git a/backend/src/uxbox/services/queries/images.clj b/backend/src/uxbox/services/queries/images.clj
index 17fb9e86d..033b37574 100644
--- a/backend/src/uxbox/services/queries/images.clj
+++ b/backend/src/uxbox/services/queries/images.clj
@@ -9,6 +9,8 @@
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
    [promesa.exec :as px]
+   [uxbox.common.exceptions :as ex]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.media :as media]
    [uxbox.images :as images]
@@ -16,8 +18,6 @@
    [uxbox.services.util :as su]
    [uxbox.util.blob :as blob]
    [uxbox.util.data :as data]
-   [uxbox.util.exceptions :as ex]
-   [uxbox.util.spec :as us]
    [uxbox.util.uuid :as uuid]
    [vertx.core :as vc]))
 
@@ -75,8 +75,9 @@
                 and deleted_at is null;"]
     (db/query-one conn [sql id])))
 
+(s/def ::id ::us/uuid)
 (s/def ::image-by-id
-  (s/keys :req-un [::user ::us/id]))
+  (s/keys :req-un [::user ::id]))
 
 (sq/defquery ::image-by-id
   [params]
diff --git a/backend/src/uxbox/services/queries/project_files.clj b/backend/src/uxbox/services/queries/project_files.clj
index c103cc87b..92df618e7 100644
--- a/backend/src/uxbox/services/queries/project_files.clj
+++ b/backend/src/uxbox/services/queries/project_files.clj
@@ -9,11 +9,11 @@
    [clojure.spec.alpha :as s]
    [cuerdas.core :as str]
    [promesa.core :as p]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.services.queries :as sq]
    [uxbox.services.util :as su]
-   [uxbox.util.blob :as blob]
-   [uxbox.util.spec :as us]))
+   [uxbox.util.blob :as blob]))
 
 (declare decode-row)
 
diff --git a/backend/src/uxbox/services/queries/project_pages.clj b/backend/src/uxbox/services/queries/project_pages.clj
index e19530f95..c2e884609 100644
--- a/backend/src/uxbox/services/queries/project_pages.clj
+++ b/backend/src/uxbox/services/queries/project_pages.clj
@@ -8,11 +8,11 @@
   (:require
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.services.queries :as sq]
    [uxbox.services.util :as su]
    [uxbox.util.blob :as blob]
-   [uxbox.util.spec :as us]
    [uxbox.util.sql :as sql]))
 
 ;; --- Helpers & Specs
diff --git a/backend/src/uxbox/services/queries/projects.clj b/backend/src/uxbox/services/queries/projects.clj
index c47c04479..b428f67be 100644
--- a/backend/src/uxbox/services/queries/projects.clj
+++ b/backend/src/uxbox/services/queries/projects.clj
@@ -8,11 +8,11 @@
   (:require
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.services.queries :as sq]
    [uxbox.services.util :as su]
-   [uxbox.util.blob :as blob]
-   [uxbox.util.spec :as us]))
+   [uxbox.util.blob :as blob]))
 
 (declare decode-row)
 
diff --git a/backend/src/uxbox/services/queries/user_attrs.clj b/backend/src/uxbox/services/queries/user_attrs.clj
index 4498e2a46..8a86c73fe 100644
--- a/backend/src/uxbox/services/queries/user_attrs.clj
+++ b/backend/src/uxbox/services/queries/user_attrs.clj
@@ -8,11 +8,11 @@
   (:require
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.services.queries :as sq]
    [uxbox.services.util :as su]
-   [uxbox.util.blob :as blob]
-   [uxbox.util.spec :as us]))
+   [uxbox.util.blob :as blob]))
 
 (defn decode-row
   [{:keys [val] :as row}]
@@ -20,6 +20,9 @@
     (cond-> row
       val (assoc :val (blob/decode val)))))
 
+(s/def ::key ::us/string)
+(s/def ::user ::us/uuid)
+
 (s/def ::user-attr
   (s/keys :req-un [::key ::user]))
 
diff --git a/backend/src/uxbox/services/queries/users.clj b/backend/src/uxbox/services/queries/users.clj
index 55982c859..e6f228340 100644
--- a/backend/src/uxbox/services/queries/users.clj
+++ b/backend/src/uxbox/services/queries/users.clj
@@ -9,12 +9,12 @@
    [clojure.spec.alpha :as s]
    [promesa.core :as p]
    [promesa.exec :as px]
+   [uxbox.common.spec :as us]
    [uxbox.db :as db]
    [uxbox.images :as images]
    [uxbox.services.queries :as sq]
    [uxbox.services.util :as su]
-   [uxbox.util.blob :as blob]
-   [uxbox.util.spec :as us]))
+   [uxbox.util.blob :as blob]))
 
 ;; --- Helpers & Specs
 
diff --git a/backend/src/uxbox/services/util.clj b/backend/src/uxbox/services/util.clj
index 32ded7296..3b0705ca1 100644
--- a/backend/src/uxbox/services/util.clj
+++ b/backend/src/uxbox/services/util.clj
@@ -10,9 +10,9 @@
    [cuerdas.core :as str]
    [vertx.core :as vc]
    [uxbox.core :refer [system]]
+   [uxbox.common.exceptions :as ex]
    [uxbox.util.uuid :as uuid]
-   [uxbox.util.dispatcher :as uds]
-   [uxbox.util.exceptions :as ex]))
+   [uxbox.util.dispatcher :as uds]))
 
 ;; (def logging-interceptor
 ;;   {:enter (fn [data]
diff --git a/backend/src/uxbox/util/dispatcher.clj b/backend/src/uxbox/util/dispatcher.clj
index db9588b54..4d304e109 100644
--- a/backend/src/uxbox/util/dispatcher.clj
+++ b/backend/src/uxbox/util/dispatcher.clj
@@ -13,8 +13,7 @@
    [expound.alpha :as expound]
    [sieppari.core :as sp]
    [sieppari.context :as spx]
-   [uxbox.util.spec :as us]
-   [uxbox.util.exceptions :as ex])
+   [uxbox.common.exceptions :as ex])
   (:import
    clojure.lang.IDeref
    clojure.lang.MapEntry
diff --git a/backend/src/uxbox/util/emails.clj b/backend/src/uxbox/util/emails.clj
index 02534840a..4b819ccd3 100644
--- a/backend/src/uxbox/util/emails.clj
+++ b/backend/src/uxbox/util/emails.clj
@@ -10,8 +10,8 @@
    [clojure.spec.alpha :as s]
    [cuerdas.core :as str]
    [instaparse.core :as insta]
-   [uxbox.util.exceptions :as ex]
-   [uxbox.util.spec :as us]
+   [uxbox.common.spec :as us]
+   [uxbox.common.exceptions :as ex]
    [uxbox.util.template :as tmpl]))
 
 ;; --- Impl.
@@ -44,9 +44,9 @@
                (rest parts)))
       state)))
 
-(s/def ::subject ::us/string)
-(s/def ::body-text ::us/string)
-(s/def ::body-html ::us/string)
+(s/def ::subject string?)
+(s/def ::body-text string?)
+(s/def ::body-html string?)
 
 (s/def ::parsed-email
   (s/keys :req-un [::subject ::body-html ::body-html]))
@@ -79,7 +79,7 @@
 (s/def ::to ::us/email)
 (s/def ::from ::us/email)
 (s/def ::reply-to ::us/email)
-(s/def ::lang ::us/string)
+(s/def ::lang string?)
 
 (s/def ::context
   (s/keys :req-un [::to]
@@ -90,7 +90,7 @@
   ([id extra-context]
    (s/assert keyword? id)
    (fn [context]
-     (s/assert ::context context)
+     (us/assert ::context context)
      (when-let [spec (s/get-spec id)]
        (s/assert spec context))
 
diff --git a/backend/src/uxbox/util/exceptions.clj b/backend/src/uxbox/util/exceptions.clj
deleted file mode 100644
index f5bdde57b..000000000
--- a/backend/src/uxbox/util/exceptions.clj
+++ /dev/null
@@ -1,34 +0,0 @@
-;; This Source Code Form is subject to the terms of the Mozilla Public
-;; License, v. 2.0. If a copy of the MPL was not distributed with this
-;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
-;;
-;; Copyright (c) 2016 Andrey Antukh <niwi@niwi.nz>
-
-;; WARNING: DEPRECATED: please use uxbox.common.exceptions
-
-(ns uxbox.util.exceptions
-  "A helpers for work with exceptions."
-  (:require [clojure.spec.alpha :as s]))
-
-(s/def ::type keyword?)
-(s/def ::code keyword?)
-(s/def ::mesage string?)
-(s/def ::hint string?)
-(s/def ::cause #(instance? Throwable %))
-(s/def ::error-params
-  (s/keys :req-un [::type]
-          :opt-un [::code
-                   ::hint
-                   ::mesage
-                   ::cause]))
-
-(defn error
-  [& {:keys [type code message hint cause] :as params}]
-  (s/assert ::error-params params)
-  (let [message (or message hint "")
-        payload (dissoc params :cause :message)]
-    (ex-info message payload cause)))
-
-(defmacro raise
-  [& args]
-  `(throw (error ~@args)))
diff --git a/backend/src/uxbox/util/spec.clj b/backend/src/uxbox/util/spec.clj
deleted file mode 100644
index 1fac49aaf..000000000
--- a/backend/src/uxbox/util/spec.clj
+++ /dev/null
@@ -1,145 +0,0 @@
-;; This Source Code Form is subject to the terms of the Mozilla Public
-;; License, v. 2.0. If a copy of the MPL was not distributed with this
-;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
-;;
-;; Copyright (c) 2016-2019 Andrey Antukh <niwi@niwi.nz>
-
-;; WARNING: DEPRECATED: please use uxbox.common.spec
-
-(ns uxbox.util.spec
-  (:refer-clojure :exclude [keyword uuid vector boolean map set])
-  (:require
-   [clojure.spec.alpha :as s]
-   [cuerdas.core :as str]
-   [datoteka.core :as fs]
-   [expound.alpha :as expound]
-   [uxbox.util.exceptions :as ex])
-  (:import java.time.Instant))
-
-(s/check-asserts true)
-
-;; --- Constants
-
-(def email-rx
-  #"^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$")
-
-(def uuid-rx
-  #"^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$")
-
-;; --- Public Api
-
-(defn conform
-  [spec data]
-  (let [result (s/conform spec data)]
-    (when (= result ::s/invalid)
-      (throw (ex/error :type :validation
-                       :code :spec-validation
-                       :explain (with-out-str
-                                  (expound/printer data))
-                       :data (::s/problems data))))
-    result))
-
-;; --- Predicates
-
-(defn email?
-  [v]
-  (and (string? v)
-       (re-matches email-rx v)))
-
-(defn instant?
-  [v]
-  (instance? Instant v))
-
-(defn path?
-  [v]
-  (instance? java.nio.file.Path v))
-
-(defn regex?
-  [v]
-  (instance? java.util.regex.Pattern v))
-
-;; --- Conformers
-
-(defn- uuid-conformer
-  [v]
-  (cond
-    (uuid? v) v
-    (string? v)
-    (cond
-      (re-matches uuid-rx v)
-      (java.util.UUID/fromString v)
-
-      (str/empty? v)
-      nil
-
-      :else
-      ::s/invalid)
-    :else ::s/invalid))
-
-(defn- integer-conformer
-  [v]
-  (cond
-    (integer? v) v
-    (string? v)
-    (if (re-matches #"^[-+]?\d+$" v)
-      (Long/parseLong v)
-      ::s/invalid)
-    :else ::s/invalid))
-
-(defn boolean-conformer
-  [v]
-  (cond
-    (boolean? v) v
-    (string? v)
-    (if (re-matches #"^(?:t|true|false|f|0|1)$" v)
-      (contains? #{"t" "true" "1"} v)
-      ::s/invalid)
-    :else ::s/invalid))
-
-(defn boolean-unformer
-  [v]
-  (if v "true" "false"))
-
-(defn path-conformer
-  [v]
-  (cond
-   (string? v) (fs/path v)
-   (fs/path? v) v
-   :else ::s/invalid))
-
-(defn- number-conformer
-  [v]
-  (cond
-    (number? v) v
-    (str/numeric? v) (Double/parseDouble v)
-    :else ::s/invalid))
-
-
-;; --- Default Specs
-
-(s/def ::string string?)
-(s/def ::integer (s/conformer integer-conformer str))
-(s/def ::uuid (s/conformer uuid-conformer str))
-(s/def ::boolean (s/conformer boolean-conformer boolean-unformer))
-(s/def ::number (s/conformer number-conformer str))
-(s/def ::path (s/conformer path-conformer str))
-
-(s/def ::positive pos?)
-(s/def ::negative neg?)
-(s/def ::uploaded-file any?)
-(s/def ::bytes bytes?)
-(s/def ::email email?)
-(s/def ::file any?)
-
-(s/def ::name ::string)
-(s/def ::size ::integer)
-(s/def ::mtype ::string)
-(s/def ::upload
-  (s/keys :req-un [::name ::path ::size ::mtype]))
-
-;; TODO: deprecated
-(s/def ::id ::uuid)
-(s/def ::username ::string)
-(s/def ::password ::string)
-(s/def ::token ::string)
-
diff --git a/backend/src/uxbox/util/svg.clj b/backend/src/uxbox/util/svg.clj
index f646cad26..7c8147d50 100644
--- a/backend/src/uxbox/util/svg.clj
+++ b/backend/src/uxbox/util/svg.clj
@@ -9,8 +9,8 @@
   (:require
    [clojure.spec.alpha :as s]
    [cuerdas.core :as str]
-   [uxbox.util.spec :as us]
-   [uxbox.util.exceptions :as ex])
+   [uxbox.common.spec :as us]
+   [uxbox.common.exceptions :as ex])
   (:import
    org.jsoup.Jsoup
    org.jsoup.nodes.Attribute
@@ -18,10 +18,10 @@
    org.jsoup.nodes.Document
    java.io.InputStream))
 
-(s/def ::content ::us/string)
+(s/def ::content string?)
 (s/def ::width ::us/number)
 (s/def ::height ::us/number)
-(s/def ::name ::us/string)
+(s/def ::name string?)
 (s/def ::view-box (s/coll-of ::us/number :min-count 4 :max-count 4))
 
 (s/def ::svg-entity
diff --git a/backend/src/uxbox/util/template.clj b/backend/src/uxbox/util/template.clj
index a2ac92915..a48ef1ea1 100644
--- a/backend/src/uxbox/util/template.clj
+++ b/backend/src/uxbox/util/template.clj
@@ -11,7 +11,7 @@
    [clojure.tools.logging :as log]
    [clojure.walk :as walk]
    [clojure.java.io :as io]
-   [uxbox.util.exceptions :as ex])
+   [uxbox.common.exceptions :as ex])
   (:import
    java.io.StringReader
    java.util.HashMap
diff --git a/common/uxbox/common/data.cljc b/common/uxbox/common/data.cljc
index ad5be360a..4774241a5 100644
--- a/common/uxbox/common/data.cljc
+++ b/common/uxbox/common/data.cljc
@@ -15,6 +15,17 @@
 ;; Data Structures Manipulation
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
+(defn dissoc-in
+  [m [k & ks :as keys]]
+  (if ks
+    (if-let [nextmap (get m k)]
+      (let [newmap (dissoc-in nextmap ks)]
+        (if (seq newmap)
+          (assoc m k newmap)
+          (dissoc m k)))
+      m)
+    (dissoc m k)))
+
 (defn concat
   [& colls]
   (loop [result (first colls)
diff --git a/common/uxbox/common/spec.cljc b/common/uxbox/common/spec.cljc
index f3319f733..10ed85db7 100644
--- a/common/uxbox/common/spec.cljc
+++ b/common/uxbox/common/spec.cljc
@@ -98,6 +98,7 @@
 ;; --- Default Specs
 
 (s/def ::inst inst?)
+(s/def ::string string?)
 (s/def ::email (s/conformer email-conformer str))
 (s/def ::color (s/conformer color-conformer str))
 (s/def ::uuid (s/conformer uuid-conformer str))