diff --git a/.air.toml b/.air.toml
new file mode 100644
index 0000000..1809a35
--- /dev/null
+++ b/.air.toml
@@ -0,0 +1,46 @@
+root = "."
+testdata_dir = "testdata"
+tmp_dir = "tmp"
+
+[build]
+  args_bin = []
+  bin = "tmp\\main.exe"
+  cmd = "go build -o ./tmp/main.exe ."
+  delay = 1000
+  exclude_dir = ["assets", "tmp", "vendor", "testdata"]
+  exclude_file = []
+  exclude_regex = ["_test.go"]
+  exclude_unchanged = false
+  follow_symlink = false
+  full_bin = ""
+  include_dir = []
+  include_ext = ["go", "tpl", "tmpl", "html"]
+  include_file = []
+  kill_delay = "0s"
+  log = "build-errors.log"
+  poll = false
+  poll_interval = 0
+  post_cmd = []
+  pre_cmd = ["swag init"]
+  rerun = false
+  rerun_delay = 500
+  send_interrupt = false
+  stop_on_error = false
+
+[color]
+  app = ""
+  build = "yellow"
+  main = "magenta"
+  runner = "green"
+  watcher = "cyan"
+
+[log]
+  main_only = false
+  time = false
+
+[misc]
+  clean_on_exit = false
+
+[screen]
+  clear_on_rebuild = false
+  keep_scroll = true
diff --git a/docs/docs.go b/docs/docs.go
index 88c2812..1c545a7 100644
--- a/docs/docs.go
+++ b/docs/docs.go
@@ -47,6 +47,13 @@ const docTemplate = `{
         "models.Contract": {
             "type": "object",
             "properties": {
+                "locale": {
+                    "type": "string",
+                    "enum": [
+                        "en",
+                        "de"
+                    ]
+                },
                 "runners": {
                     "type": "array",
                     "items": {
diff --git a/docs/swagger.json b/docs/swagger.json
index 2fd44f1..4d57eeb 100644
--- a/docs/swagger.json
+++ b/docs/swagger.json
@@ -38,6 +38,13 @@
         "models.Contract": {
             "type": "object",
             "properties": {
+                "locale": {
+                    "type": "string",
+                    "enum": [
+                        "en",
+                        "de"
+                    ]
+                },
                 "runners": {
                     "type": "array",
                     "items": {
diff --git a/docs/swagger.yaml b/docs/swagger.yaml
index 7da2257..2072fc0 100644
--- a/docs/swagger.yaml
+++ b/docs/swagger.yaml
@@ -1,6 +1,11 @@
 definitions:
   models.Contract:
     properties:
+      locale:
+        enum:
+        - en
+        - de
+        type: string
       runners:
         items:
           $ref: '#/definitions/models.Runner'