diff --git a/clients/algoliasearch-client-go/algolia/utils/utils.go b/clients/algoliasearch-client-go/algolia/utils/utils.go
index a7fd0a4338..317a2eb975 100644
--- a/clients/algoliasearch-client-go/algolia/utils/utils.go
+++ b/clients/algoliasearch-client-go/algolia/utils/utils.go
@@ -26,7 +26,7 @@ func (v Nullable[T]) Get() *T {
 
 func (v *Nullable[T]) Set(val *T) {
 	v.value = val
-	v.isSet = true
+	v.isSet = val != nil
 }
 
 func (v Nullable[T]) IsSet() bool {
@@ -39,7 +39,7 @@ func (v *Nullable[T]) Unset() {
 }
 
 func NewNullable[T any](val *T) *Nullable[T] {
-	return &Nullable[T]{value: val, isSet: true}
+	return &Nullable[T]{value: val, isSet: val != nil}
 }
 
 func (v Nullable[T]) MarshalJSON() ([]byte, error) {
@@ -47,8 +47,10 @@ func (v Nullable[T]) MarshalJSON() ([]byte, error) {
 }
 
 func (v *Nullable[T]) UnmarshalJSON(src []byte) error {
-	v.isSet = true
-	return json.Unmarshal(src, &v.value)
+	err := json.Unmarshal(src, &v.value)
+	v.isSet = v.value != nil
+
+	return err
 }
 
 // IsNilOrEmpty checks if an input is nil or empty.
diff --git a/scripts/install.sh b/scripts/install.sh
index 521af27296..c4063dabba 100755
--- a/scripts/install.sh
+++ b/scripts/install.sh
@@ -19,7 +19,7 @@ apic() {
 export apic
 
 _list_languages() {
-  cat $ROOT/config/clients.config.json | jq -r 'keys[]'
+  cat $ROOT/config/clients.config.json | jq -r 'keys[] | select(. != "$schema")'
 }
 
 _list_languages_all() {
diff --git a/specs/ingestion/common/schemas/event.yml b/specs/ingestion/common/schemas/event.yml
index e7f69350ef..c8083ad51b 100644
--- a/specs/ingestion/common/schemas/event.yml
+++ b/specs/ingestion/common/schemas/event.yml
@@ -18,8 +18,10 @@ Event:
       minimum: 0
       multipleOf: 1
     data:
-      type: object
-      additionalProperties: true
+      oneOf:
+        - type: object
+          additionalProperties: true
+        - type: 'null'
     publishedAt:
       $ref: './common.yml#/publishedAt'
   required:
@@ -31,8 +33,10 @@ Event:
     - publishedAt
 
 EventStatus:
-  type: string
-  enum: [created, started, retried, failed, succeeded, critical]
+  oneOf:
+    - type: string
+      enum: [created, started, retried, failed, succeeded, critical]
+    - type: 'null'
 
 EventType:
   type: string
diff --git a/specs/ingestion/common/schemas/source.yml b/specs/ingestion/common/schemas/source.yml
index 92c142bc85..d72fa7778c 100644
--- a/specs/ingestion/common/schemas/source.yml
+++ b/specs/ingestion/common/schemas/source.yml
@@ -352,7 +352,7 @@ SourceDocker:
   properties:
     image:
       type: string
-      description: Shortname of the image, as returned by the referential.
+      description: Name of the connector.
       example: zendesk
     configuration:
       type: object
diff --git a/templates/go/model_simple.mustache b/templates/go/model_simple.mustache
index 7b9593233a..8c28c2c0aa 100644
--- a/templates/go/model_simple.mustache
+++ b/templates/go/model_simple.mustache
@@ -274,16 +274,26 @@ func (o {{classname}}) MarshalJSON() ([]byte, error) {
 	}
 	{{/vendorExtensions.x-golang-is-container}}
 	{{^vendorExtensions.x-golang-is-container}}
-	if {{#required}}true{{/required}}{{^required}}o.{{name}}.IsSet(){{/required}} {
+  {{#required}}
+  toSerialize["{{baseName}}"] = o.{{name}}.Get()
+  {{/required}}
+  {{^required}}
+  if o.{{name}}.IsSet() {
 		toSerialize["{{baseName}}"] = o.{{name}}.Get()
 	}
+  {{/required}}
 	{{/vendorExtensions.x-golang-is-container}}
 	{{/isNullable}}
 	{{! if argument is not nullable, don't set it if it is nil}}
 	{{^isNullable}}
-	if {{#required}}true{{/required}}{{^required}}o.{{name}} != nil{{/required}} {
+  {{#required}}
+  toSerialize["{{baseName}}"] = o.{{name}}
+  {{/required}}
+  {{^required}}
+  if o.{{name}} != nil {
 		toSerialize["{{baseName}}"] = o.{{name}}
 	}
+  {{/required}}
 	{{/isNullable}}
 	{{/vars}}
 	{{#isAdditionalPropertiesTrue}}
@@ -443,4 +453,4 @@ func (o {{classname}}) String() string {
 	}
 	{{/isAdditionalPropertiesTrue}}
   return fmt.Sprintf("{{classname}} {\n%s}", out)
-}
\ No newline at end of file
+}
diff --git a/templates/python/model_generic.mustache b/templates/python/model_generic.mustache
index 605ef476be..25defe31eb 100644
--- a/templates/python/model_generic.mustache
+++ b/templates/python/model_generic.mustache
@@ -12,7 +12,7 @@ class {{classname}}({{#parent}}{{{.}}}{{/parent}}{{^parent}}BaseModel{{/parent}}
 {{> model_description}}
 
 {{#vars}}
-    {{name}}: {{^required}}Optional[{{/required}}{{{dataType}}}{{^required}}]{{/required}}{{^required}} = None{{/required}}
+    {{name}}: {{^required}}Optional[{{/required}}{{#required}}{{#isNullable}}Union[{{/isNullable}}{{/required}}{{{dataType}}}{{#required}}{{#isNullable}}, None]{{/isNullable}}{{/required}}{{^required}}]{{/required}}{{^required}} = None{{/required}}
     {{#description}}
     """ {{{.}}} """
     {{/description}}
diff --git a/tests/CTS/client/ingestion/api.json b/tests/CTS/client/ingestion/api.json
index f0ec2abdc5..b5c9f063cf 100644
--- a/tests/CTS/client/ingestion/api.json
+++ b/tests/CTS/client/ingestion/api.json
@@ -102,7 +102,9 @@
         },
         "expected": {
           "type": "response",
-          "match": {"message":"OK"}
+          "match": {
+            "message": "OK"
+          }
         }
       }
     ]