diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ca00915
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,26 @@
+# pybuilder
+.pybuilder/
+__pycache__/
+
+# lein
+target/
+.lein-repl-history
+.lein-failures
+pom.*
+
+# cljs
+.shadow-cljs
+.nrepl-*
+package-lock.json
+node_modules/
+public/js/
+
+# ide
+.calva
+
+*.iml
+.idea/
+
+valid-auth.edn
+valid-config.edn
+my-auth.edn
diff --git a/project.clj b/project.clj
new file mode 100644
index 0000000..5a60c57
--- /dev/null
+++ b/project.clj
@@ -0,0 +1,28 @@
+(defproject org.domaindrivenarchitecture/c4k-common "0.1.0-SNAPSHOT"
+  :description "Contains predicates and tools for c4k"
+  :url "https://domaindrivenarchitecture.org"
+  :license {:name "Apache License, Version 2.0"
+            :url "https://www.apache.org/licenses/LICENSE-2.0.html"}
+  :dependencies [[org.clojure/clojure "1.10.3"]
+                 [org.clojure/tools.reader "1.3.4"]
+                 [aero "1.1.6"]
+                 [orchestra "2021.01.01-1"]
+                 [expound "0.8.9"]
+                 [clj-commons/clj-yaml "0.7.106"]]
+  :source-paths ["src/main/cljc"
+                 "src/main/clj"]
+  :resource-paths ["src/main/resources"]
+  :repositories [["snapshots" :clojars]
+                 ["releases" :clojars]]
+  :deploy-repositories [["snapshots" :clojars]
+                        ["releases" :clojars]]
+  :profiles {:test {:test-paths ["src/test/cljc"]
+                    :resource-paths ["src/test/resources"]
+                    :dependencies [[dda/data-test "0.1.1"]]}
+             :dev {:plugins [[lein-shell "0.5.0"]]}}
+  :release-tasks [["vcs" "assert-committed"]
+                  ["change" "version" "leiningen.release/bump-version" "release"]
+                  ["vcs" "commit"]
+                  ["vcs" "tag"]
+                  ["deploy"]
+                  ["change" "version" "leiningen.release/bump-version"]])
diff --git a/src/main/clj/dda/c4k_keycloak/base64.clj b/src/main/clj/dda/c4k_keycloak/base64.clj
new file mode 100644
index 0000000..4f9bb50
--- /dev/null
+++ b/src/main/clj/dda/c4k_keycloak/base64.clj
@@ -0,0 +1,14 @@
+(ns dda.c4k-keycloak.base64
+  (:import (java.util Base64)))
+
+(defn encode
+  [string]
+  (.encodeToString 
+   (Base64/getEncoder) 
+   (.getBytes string "UTF-8"))) 
+
+(defn decode
+  [string]
+  (String. 
+   (.decode (Base64/getDecoder) string) 
+   "UTF-8"))
\ No newline at end of file
diff --git a/src/main/clj/dda/c4k_keycloak/yaml.clj b/src/main/clj/dda/c4k_keycloak/yaml.clj
new file mode 100644
index 0000000..c05db95
--- /dev/null
+++ b/src/main/clj/dda/c4k_keycloak/yaml.clj
@@ -0,0 +1,20 @@
+(ns dda.c4k-keycloak.yaml
+  (:require
+   [clojure.java.io :as io]
+   [clj-yaml.core :as yaml]
+   [clojure.walk]))
+
+(defn cast-lazy-seq-to-vec
+  [lazy-seq]
+  (clojure.walk/postwalk #(if (instance? clojure.lang.LazySeq %)
+                            (into [] %)
+                            %) lazy-seq))
+
+(defn load-resource [resource-name]
+  (slurp (io/resource  resource-name)))
+
+(defn from-string [input]
+  (cast-lazy-seq-to-vec (yaml/parse-string input)))
+
+(defn to-string [edn]
+  (yaml/generate-string edn :dumper-options {:flow-style :block}))
\ No newline at end of file
diff --git a/src/main/cljc/dda/c4k_keycloak/common.cljc b/src/main/cljc/dda/c4k_keycloak/common.cljc
new file mode 100644
index 0000000..7beee60
--- /dev/null
+++ b/src/main/cljc/dda/c4k_keycloak/common.cljc
@@ -0,0 +1,41 @@
+(ns dda.c4k-keycloak.common
+  (:require
+   [clojure.walk]))
+
+(defn bash-env-string?
+  [input]
+  (and (string? input)
+       (not (re-matches #".*['\"\$]+.*" input))))
+
+(defn fqdn-string?
+  [input]
+  (and (string? input)
+       (some? (re-matches #"(?=^.{4,253}$)(^((?!-)[a-zA-Z0-9-]{0,62}[a-zA-Z0-9]\.)+[a-zA-Z]{2,63}$)" input))))
+
+(defn letsencrypt-issuer? 
+  [input]
+  (contains? #{:prod :staging} input))
+
+(defn replace-named-value
+  [coll name value]
+  (clojure.walk/postwalk #(if (and (map? %)
+                                   (= name (:name %)))
+                            {:name name :value value}
+                            %) 
+                         coll))
+
+(defn replace-key-value
+  [coll key value]
+  (clojure.walk/postwalk #(if (and (map? %)
+                                   (contains? % key))
+                            (assoc % key value)
+                            %)
+                         coll))
+
+(defn replace-all-matching-values-by-new-value
+  [coll value-to-match value-to-replace]
+  (clojure.walk/postwalk #(if (and (= (type value-to-match) (type %))
+                                   (= value-to-match %))
+                            value-to-replace
+                            %) 
+                         coll))
diff --git a/src/main/cljs/dda/c4k_keycloak/base64.cljs b/src/main/cljs/dda/c4k_keycloak/base64.cljs
new file mode 100644
index 0000000..8c1caa0
--- /dev/null
+++ b/src/main/cljs/dda/c4k_keycloak/base64.cljs
@@ -0,0 +1,11 @@
+(ns dda.c4k-keycloak.base64
+  (:require
+   ["js-base64" :as b64]))
+
+(defn encode
+  [string]
+  (.encode b64/Base64 string))
+
+(defn decode
+  [string]
+  (.decode b64/Base64 string))
diff --git a/src/main/cljs/dda/c4k_keycloak/browser.cljs b/src/main/cljs/dda/c4k_keycloak/browser.cljs
new file mode 100644
index 0000000..bd0296c
--- /dev/null
+++ b/src/main/cljs/dda/c4k_keycloak/browser.cljs
@@ -0,0 +1,70 @@
+(ns dda.c4k-keycloak.browser
+  (:require
+   [clojure.string :as st]
+   [clojure.spec.alpha :as s]
+   [clojure.tools.reader.edn :as edn]
+   [expound.alpha :as expound]
+   [orchestra.core :refer-macros [defn-spec]]
+   [dda.c4k-keycloak.core :as core]
+   [dda.c4k-keycloak.keycloak :as kc]))
+
+(defn-spec print-debug string?
+  [sth string?]
+  (print "debug " sth)
+  sth)
+
+(defn-spec get-element-by-id any?
+  [name string?]
+  (-> js/document
+      (.getElementById name)))
+
+(s/def ::deserializer fn?)
+(s/def ::optional boolean?)
+(defn-spec get-content-from-element any?
+  [name string?
+   & {:keys [deserializer optional]
+      :or {deserializer nil optional false}} (s/keys :opt-un [::deserializer ::optional])]
+  (let [content (-> (get-element-by-id name)
+                    (.-value))]
+    (cond
+      (and optional (some? deserializer))
+      (when-not (st/blank? content)
+        (apply deserializer [content]))
+      (and (false? optional) (some? deserializer))
+      (apply deserializer [content])
+      :else
+      content)))
+
+(defn-spec set-validation-result! any?
+  [name string?
+   validation-result any?]
+  (-> (get-element-by-id (str name "-validation"))
+      (.-innerHTML)
+      (set! validation-result))
+  (-> (get-element-by-id name)
+      (.setCustomValidity validation-result))
+  validation-result)
+
+(defn-spec validate! any?
+  [name string?
+   spec any?
+   & {:keys [deserializer optional]
+      :or {deserializer nil optional false}} (s/keys :opt-un [::deserializer ::optional])]
+  (let [content (get-content-from-element name :optional optional :deserializer deserializer)]
+    (if (or (and optional (st/blank? content)) 
+            (s/valid? spec content))
+      (set-validation-result! name "")
+      (set-validation-result! name
+       (expound/expound-str spec content {:print-specs? false})))))
+
+(defn set-output!
+  [input]
+  (-> js/document
+      (.getElementById "output")
+      (.-value)
+      (set! input)))
+
+(defn set-validated! []
+  (-> (get-element-by-id "form")
+      (.-classList)
+      (.add "was-validated")))
\ No newline at end of file
diff --git a/src/main/cljs/dda/c4k_keycloak/yaml.cljs b/src/main/cljs/dda/c4k_keycloak/yaml.cljs
new file mode 100644
index 0000000..34ab7a0
--- /dev/null
+++ b/src/main/cljs/dda/c4k_keycloak/yaml.cljs
@@ -0,0 +1,16 @@
+(ns dda.c4k-keycloak.yaml
+  (:require
+   ["js-yaml" :as yaml]
+   [shadow.resource :as rc]))
+
+(defn load-resource [resource-name]
+  (case resource-name
+    "ingress_test.yaml" (rc/inline "ingress_test.yaml")
+    (throw (js/Error. "Undefined Resource!"))))
+
+(defn from-string [input]
+  (js->clj (yaml/load input)
+           :keywordize-keys true))
+
+(defn to-string [edn]
+  (yaml/dump (clj->js  edn)))
\ No newline at end of file
diff --git a/src/test/cljc/dda/c4k_keycloak/yaml_test.cljc b/src/test/cljc/dda/c4k_keycloak/yaml_test.cljc
new file mode 100644
index 0000000..cb31273
--- /dev/null
+++ b/src/test/cljc/dda/c4k_keycloak/yaml_test.cljc
@@ -0,0 +1,45 @@
+(ns dda.c4k-keycloak.yaml-test
+  (:require
+   #?(:clj [clojure.test :refer [deftest is are testing run-tests]]
+      :cljs [cljs.test :refer-macros [deftest is are testing run-tests]])
+   [dda.c4k-keycloak.yaml :as cut]))
+
+(deftest should-parse-yaml-string
+  (is (= {:hallo "welt"}
+         (cut/from-string "hallo: welt"))))
+
+(deftest should-generate-yaml-string
+  (is (= "hallo: welt
+"
+         (cut/to-string {:hallo "welt"}))))
+
+(deftest should-convert-config-yml-to-map
+  (is (= {:apiVersion "networking.k8s.io/v1beta1"
+          :kind "Ingress"
+          :metadata
+          {:name "ingress-cloud"
+           :annotations
+           {:cert-manager.io/cluster-issuer
+            "letsencrypt-staging-issuer"
+            :nginx.ingress.kubernetes.io/proxy-body-size "256m"
+            :nginx.ingress.kubernetes.io/ssl-redirect "true"
+            :nginx.ingress.kubernetes.io/rewrite-target "/"
+            :nginx.ingress.kubernetes.io/proxy-connect-timeout "300"
+            :nginx.ingress.kubernetes.io/proxy-send-timeout "300"
+            :nginx.ingress.kubernetes.io/proxy-read-timeout "300"}
+           :namespace "default"}
+          :spec
+          {:tls [{:hosts ["fqdn"], :secretName "keycloak-secret"}]
+           :rules
+           [{:host "fqdn"
+             :http
+             {:paths
+              [{:backend
+                {:serviceName "keycloak", :servicePort 8080}}]}}
+            {:host "fqdn"
+             :http
+             {:paths
+              [{:backend
+                {:serviceName "another_keycloak"
+                 :servicePort 8081}}]}}]}}
+         (cut/from-string (cut/load-resource "ingress_test.yaml")))))
diff --git a/src/test/resources/ingress_test.yaml b/src/test/resources/ingress_test.yaml
new file mode 100644
index 0000000..ed5d4b0
--- /dev/null
+++ b/src/test/resources/ingress_test.yaml
@@ -0,0 +1,31 @@
+apiVersion: networking.k8s.io/v1beta1
+kind: Ingress
+metadata:
+  name: ingress-cloud
+  annotations:
+    cert-manager.io/cluster-issuer: letsencrypt-staging-issuer
+    nginx.ingress.kubernetes.io/proxy-body-size: "256m"
+    nginx.ingress.kubernetes.io/ssl-redirect: "true"
+    nginx.ingress.kubernetes.io/rewrite-target: /
+    nginx.ingress.kubernetes.io/proxy-connect-timeout: "300"
+    nginx.ingress.kubernetes.io/proxy-send-timeout: "300"
+    nginx.ingress.kubernetes.io/proxy-read-timeout: "300"
+  namespace: default
+spec:
+  tls:
+  - hosts:
+    - fqdn
+    secretName: keycloak-secret
+  rules:
+    - host: fqdn
+      http:
+        paths:
+        - backend:
+            serviceName: keycloak
+            servicePort: 8080
+    - host: fqdn
+      http:
+        paths:
+        - backend:
+            serviceName: another_keycloak
+            servicePort: 8081
\ No newline at end of file