diff --git a/CI/circle_parallel.sh b/CI/circle_parallel.sh
index 9c55aeea28c..f10d419eca0 100755
--- a/CI/circle_parallel.sh
+++ b/CI/circle_parallel.sh
@@ -74,8 +74,8 @@ elif [ "$NODE_INDEX" = "3" ]; then
   [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
   #nvm install stable
   # install v16 instead of the latest stable version
-  nvm install 16
-  nvm alias default 16
+  nvm install 18
+  nvm alias default 18
   node --version
 
   # Each step uses the same `$BASH_ENV`, so need to modify it
diff --git a/bin/configs/typescript-angular-v19-deep-object.yaml b/bin/configs/typescript-angular-v19-deep-object.yaml
new file mode 100644
index 00000000000..e588d61a68c
--- /dev/null
+++ b/bin/configs/typescript-angular-v19-deep-object.yaml
@@ -0,0 +1,8 @@
+generatorName: typescript-angular
+outputDir: samples/client/petstore/typescript-angular-v19/builds/deep-object
+inputSpec: modules/openapi-generator/src/test/resources/3_0/deep-object-query.yaml
+templateDir: modules/openapi-generator/src/main/resources/typescript-angular
+additionalProperties:
+  ngVersion: 19.0.0
+  npmName: sample-angular-19-0-0-deep-object
+  supportsES6: true
diff --git a/modules/openapi-generator/src/main/resources/typescript-angular/api.base.service.mustache b/modules/openapi-generator/src/main/resources/typescript-angular/api.base.service.mustache
index 311fd1aa079..70e4601cbf8 100644
--- a/modules/openapi-generator/src/main/resources/typescript-angular/api.base.service.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-angular/api.base.service.mustache
@@ -29,22 +29,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/modules/openapi-generator/src/main/resources/typescript-angular/api.service.mustache b/modules/openapi-generator/src/main/resources/typescript-angular/api.service.mustache
index 31184b79de2..c48a2b6b6f0 100644
--- a/modules/openapi-generator/src/main/resources/typescript-angular/api.service.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-angular/api.service.mustache
@@ -130,7 +130,7 @@ export class {{classname}} extends BaseService {
         {{/isArray}}
         {{^isArray}}
         localVarQueryParameters = this.addToHttpParams(localVarQueryParameters,
-          <any>{{paramName}}, '{{baseName}}');
+          <any>{{paramName}}, '{{baseName}}'{{#isDeepObject}}, true{{/isDeepObject}});
         {{/isArray}}
 {{/queryParams}}
 
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/typescriptangular/TypeScriptAngularClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/typescriptangular/TypeScriptAngularClientCodegenTest.java
index fc169b604fc..c1935f26ac9 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/typescriptangular/TypeScriptAngularClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/typescriptangular/TypeScriptAngularClientCodegenTest.java
@@ -464,4 +464,29 @@ public class TypeScriptAngularClientCodegenTest {
         assertThat(fileContents).containsOnlyOnce("} as const;");
         assertThat(fileContents).doesNotContain(" as Type");
     }
+
+    @Test
+    public void testDeepObject() throws IOException {
+        // GIVEN
+        final String specPath = "src/test/resources/3_0/deepobject.yaml";
+
+        File output = Files.createTempDirectory("test").toFile();
+        output.deleteOnExit();
+
+        // WHEN
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+            .setGeneratorName("typescript-angular")
+            .setInputSpec(specPath)
+            .setOutputDir(output.getAbsolutePath().replace("\\", "/"));
+
+        final ClientOptInput clientOptInput = configurator.toClientOptInput();
+
+        Generator generator = new DefaultGenerator();
+        generator.opts(clientOptInput).generate();
+
+        // THEN
+        final String fileContents = Files.readString(Paths.get(output + "/api/default.service.ts"));
+        assertThat(fileContents).containsOnlyOnce("<any>options, 'options', true);");
+        assertThat(fileContents).containsOnlyOnce("<any>inputOptions, 'inputOptions', true);");
+    }
 }
diff --git a/modules/openapi-generator/src/test/resources/3_0/deep-object-query.yaml b/modules/openapi-generator/src/test/resources/3_0/deep-object-query.yaml
new file mode 100644
index 00000000000..ee263a4768e
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/deep-object-query.yaml
@@ -0,0 +1,49 @@
+openapi: 3.0.0
+info:
+  title: deepobject-query
+  version: 1.0.0
+paths:
+  /car:
+    get:
+      operationId: getCars
+      parameters:
+        - name: filter
+          in: query
+          required: false
+          style: deepObject
+          schema:
+            $ref: '#/components/schemas/CarFilter'
+          explode: true
+      responses:
+        '200':
+          description: OK
+          content:
+            text/plain:
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/Car'
+components:
+  schemas:
+    Car:
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+          example: 1
+        make:
+          type: string
+          example: Toyota
+        model:
+          type: string
+          example: Camry
+    CarFilter:
+      type: object
+      properties:
+        make:
+          type: string
+          example: Toyota
+        model:
+          type: string
+          example: Camry
diff --git a/samples/client/others/typescript-angular/builds/composed-schemas-tagged-unions/api.base.service.ts b/samples/client/others/typescript-angular/builds/composed-schemas-tagged-unions/api.base.service.ts
index b4e99170329..5800e940ea6 100644
--- a/samples/client/others/typescript-angular/builds/composed-schemas-tagged-unions/api.base.service.ts
+++ b/samples/client/others/typescript-angular/builds/composed-schemas-tagged-unions/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/others/typescript-angular/builds/composed-schemas/api.base.service.ts b/samples/client/others/typescript-angular/builds/composed-schemas/api.base.service.ts
index b4e99170329..5800e940ea6 100644
--- a/samples/client/others/typescript-angular/builds/composed-schemas/api.base.service.ts
+++ b/samples/client/others/typescript-angular/builds/composed-schemas/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v12-oneOf/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v12-oneOf/builds/default/api.base.service.ts
index 14cc2405f03..9ed72856f87 100644
--- a/samples/client/petstore/typescript-angular-v12-oneOf/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v12-oneOf/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v12-provided-in-any/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v12-provided-in-any/builds/default/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v12-provided-in-any/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v12-provided-in-any/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v12-provided-in-root/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v12-provided-in-root/builds/default/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v12-provided-in-root/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v12-provided-in-root/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v12-provided-in-root/builds/with-npm/api.base.service.ts b/samples/client/petstore/typescript-angular-v12-provided-in-root/builds/with-npm/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v12-provided-in-root/builds/with-npm/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v12-provided-in-root/builds/with-npm/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v13-oneOf/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v13-oneOf/builds/default/api.base.service.ts
index 14cc2405f03..9ed72856f87 100644
--- a/samples/client/petstore/typescript-angular-v13-oneOf/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v13-oneOf/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v13-provided-in-any/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v13-provided-in-any/builds/default/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v13-provided-in-any/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v13-provided-in-any/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v13-provided-in-root/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v13-provided-in-root/builds/default/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v13-provided-in-root/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v13-provided-in-root/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v13-provided-in-root/builds/with-npm/api.base.service.ts b/samples/client/petstore/typescript-angular-v13-provided-in-root/builds/with-npm/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v13-provided-in-root/builds/with-npm/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v13-provided-in-root/builds/with-npm/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v14-provided-in-root/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v14-provided-in-root/builds/default/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v14-provided-in-root/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v14-provided-in-root/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v14-query-param-object-format/api.base.service.ts b/samples/client/petstore/typescript-angular-v14-query-param-object-format/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v14-query-param-object-format/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v14-query-param-object-format/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v15-provided-in-root/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v15-provided-in-root/builds/default/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v15-provided-in-root/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v15-provided-in-root/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v16-provided-in-root/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v16-provided-in-root/builds/default/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v16-provided-in-root/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v16-provided-in-root/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v16-provided-in-root/tests/default/src/test/api.spec.ts b/samples/client/petstore/typescript-angular-v16-provided-in-root/tests/default/src/test/api.spec.ts
index d1b1583e6f7..75bd04b513f 100644
--- a/samples/client/petstore/typescript-angular-v16-provided-in-root/tests/default/src/test/api.spec.ts
+++ b/samples/client/petstore/typescript-angular-v16-provided-in-root/tests/default/src/test/api.spec.ts
@@ -142,4 +142,4 @@ describe('API (functionality)', () => {
       )
     }))
   })
-})
+})
\ No newline at end of file
diff --git a/samples/client/petstore/typescript-angular-v17-provided-in-root/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v17-provided-in-root/builds/default/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v17-provided-in-root/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v17-provided-in-root/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v18-provided-in-root/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v18-provided-in-root/builds/default/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v18-provided-in-root/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v18-provided-in-root/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v19-with-angular-dependency-params/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v19-with-angular-dependency-params/builds/default/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v19-with-angular-dependency-params/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v19-with-angular-dependency-params/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/.gitignore b/samples/client/petstore/typescript-angular-v19/builds/deep-object/.gitignore
new file mode 100644
index 00000000000..149b5765472
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/.gitignore
@@ -0,0 +1,4 @@
+wwwroot/*.js
+node_modules
+typings
+dist
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/.openapi-generator-ignore b/samples/client/petstore/typescript-angular-v19/builds/deep-object/.openapi-generator-ignore
new file mode 100644
index 00000000000..7484ee590a3
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/.openapi-generator-ignore
@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/.openapi-generator/FILES b/samples/client/petstore/typescript-angular-v19/builds/deep-object/.openapi-generator/FILES
new file mode 100644
index 00000000000..ccf56e44302
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/.openapi-generator/FILES
@@ -0,0 +1,18 @@
+.gitignore
+README.md
+api.base.service.ts
+api.module.ts
+api/api.ts
+api/default.service.ts
+configuration.ts
+encoder.ts
+git_push.sh
+index.ts
+model/car.ts
+model/carFilter.ts
+model/models.ts
+ng-package.json
+package.json
+param.ts
+tsconfig.json
+variables.ts
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/.openapi-generator/VERSION b/samples/client/petstore/typescript-angular-v19/builds/deep-object/.openapi-generator/VERSION
new file mode 100644
index 00000000000..4c631cf217a
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/.openapi-generator/VERSION
@@ -0,0 +1 @@
+7.14.0-SNAPSHOT
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/README.md b/samples/client/petstore/typescript-angular-v19/builds/deep-object/README.md
new file mode 100644
index 00000000000..6ba9dab015b
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/README.md
@@ -0,0 +1,236 @@
+# sample-angular-19-0-0-deep-object@1.0.0
+
+No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+
+The version of the OpenAPI document: 1.0.0
+
+## Building
+
+To install the required dependencies and to build the typescript sources run:
+
+```console
+npm install
+npm run build
+```
+
+## Publishing
+
+First build the package then run `npm publish dist` (don't forget to specify the `dist` folder!)
+
+## Consuming
+
+Navigate to the folder of your consuming project and run one of next commands.
+
+_published:_
+
+```console
+npm install sample-angular-19-0-0-deep-object@1.0.0 --save
+```
+
+_without publishing (not recommended):_
+
+```console
+npm install PATH_TO_GENERATED_PACKAGE/dist.tgz --save
+```
+
+_It's important to take the tgz file, otherwise you'll get trouble with links on windows_
+
+_using `npm link`:_
+
+In PATH_TO_GENERATED_PACKAGE/dist:
+
+```console
+npm link
+```
+
+In your project:
+
+```console
+npm link sample-angular-19-0-0-deep-object
+```
+
+__Note for Windows users:__ The Angular CLI has troubles to use linked npm packages.
+Please refer to this issue <https://github.com/angular/angular-cli/issues/8284> for a solution / workaround.
+Published packages are not effected by this issue.
+
+### General usage
+
+In your Angular project:
+
+```typescript
+// without configuring providers
+import { ApiModule } from 'sample-angular-19-0-0-deep-object';
+import { HttpClientModule } from '@angular/common/http';
+
+@NgModule({
+    imports: [
+        ApiModule,
+        // make sure to import the HttpClientModule in the AppModule only,
+        // see https://github.com/angular/angular/issues/20575
+        HttpClientModule
+    ],
+    declarations: [ AppComponent ],
+    providers: [],
+    bootstrap: [ AppComponent ]
+})
+export class AppModule {}
+```
+
+```typescript
+// configuring providers
+import { ApiModule, Configuration, ConfigurationParameters } from 'sample-angular-19-0-0-deep-object';
+
+export function apiConfigFactory (): Configuration {
+  const params: ConfigurationParameters = {
+    // set configuration parameters here.
+  }
+  return new Configuration(params);
+}
+
+@NgModule({
+    imports: [ ApiModule.forRoot(apiConfigFactory) ],
+    declarations: [ AppComponent ],
+    providers: [],
+    bootstrap: [ AppComponent ]
+})
+export class AppModule {}
+```
+
+```typescript
+// configuring providers with an authentication service that manages your access tokens
+import { ApiModule, Configuration } from 'sample-angular-19-0-0-deep-object';
+
+@NgModule({
+    imports: [ ApiModule ],
+    declarations: [ AppComponent ],
+    providers: [
+      {
+        provide: Configuration,
+        useFactory: (authService: AuthService) => new Configuration(
+          {
+            basePath: environment.apiUrl,
+            accessToken: authService.getAccessToken.bind(authService)
+          }
+        ),
+        deps: [AuthService],
+        multi: false
+      }
+    ],
+    bootstrap: [ AppComponent ]
+})
+export class AppModule {}
+```
+
+```typescript
+import { DefaultApi } from 'sample-angular-19-0-0-deep-object';
+
+export class AppComponent {
+    constructor(private apiGateway: DefaultApi) { }
+}
+```
+
+Note: The ApiModule is restricted to being instantiated once app wide.
+This is to ensure that all services are treated as singletons.
+
+### Using multiple OpenAPI files / APIs / ApiModules
+
+In order to use multiple `ApiModules` generated from different OpenAPI files,
+you can create an alias name when importing the modules
+in order to avoid naming conflicts:
+
+```typescript
+import { ApiModule } from 'my-api-path';
+import { ApiModule as OtherApiModule } from 'my-other-api-path';
+import { HttpClientModule } from '@angular/common/http';
+
+@NgModule({
+  imports: [
+    ApiModule,
+    OtherApiModule,
+    // make sure to import the HttpClientModule in the AppModule only,
+    // see https://github.com/angular/angular/issues/20575
+    HttpClientModule
+  ]
+})
+export class AppModule {
+
+}
+```
+
+### Set service base path
+
+If different than the generated base path, during app bootstrap, you can provide the base path to your service.
+
+```typescript
+import { BASE_PATH } from 'sample-angular-19-0-0-deep-object';
+
+bootstrap(AppComponent, [
+    { provide: BASE_PATH, useValue: 'https://your-web-service.com' },
+]);
+```
+
+or
+
+```typescript
+import { BASE_PATH } from 'sample-angular-19-0-0-deep-object';
+
+@NgModule({
+    imports: [],
+    declarations: [ AppComponent ],
+    providers: [ provide: BASE_PATH, useValue: 'https://your-web-service.com' ],
+    bootstrap: [ AppComponent ]
+})
+export class AppModule {}
+```
+
+### Using @angular/cli
+
+First extend your `src/environments/*.ts` files by adding the corresponding base path:
+
+```typescript
+export const environment = {
+  production: false,
+  API_BASE_PATH: 'http://127.0.0.1:8080'
+};
+```
+
+In the src/app/app.module.ts:
+
+```typescript
+import { BASE_PATH } from 'sample-angular-19-0-0-deep-object';
+import { environment } from '../environments/environment';
+
+@NgModule({
+  declarations: [
+    AppComponent
+  ],
+  imports: [ ],
+  providers: [{ provide: BASE_PATH, useValue: environment.API_BASE_PATH }],
+  bootstrap: [ AppComponent ]
+})
+export class AppModule { }
+```
+
+### Customizing path parameter encoding
+
+Without further customization, only [path-parameters][parameter-locations-url] of [style][style-values-url] 'simple'
+and Dates for format 'date-time' are encoded correctly.
+
+Other styles (e.g. "matrix") are not that easy to encode
+and thus are best delegated to other libraries (e.g.: [@honoluluhenk/http-param-expander]).
+
+To implement your own parameter encoding (or call another library),
+pass an arrow-function or method-reference to the `encodeParam` property of the Configuration-object
+(see [General Usage](#general-usage) above).
+
+Example value for use in your Configuration-Provider:
+
+```typescript
+new Configuration({
+    encodeParam: (param: Param) => myFancyParamEncoder(param),
+})
+```
+
+[parameter-locations-url]: https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#parameter-locations
+[style-values-url]: https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#style-values
+[@honoluluhenk/http-param-expander]: https://www.npmjs.com/package/@honoluluhenk/http-param-expander
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/api.base.service.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/api.base.service.ts
new file mode 100644
index 00000000000..c78251fdde1
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/api.base.service.ts
@@ -0,0 +1,83 @@
+/**
+ * deepobject-query
+ *
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+import { HttpHeaders, HttpParams, HttpParameterCodec } from '@angular/common/http';
+import { CustomHttpParameterCodec } from './encoder';
+import { Configuration } from './configuration';
+
+export class BaseService {
+    protected basePath = 'http://localhost';
+    public defaultHeaders = new HttpHeaders();
+    public configuration: Configuration;
+    public encoder: HttpParameterCodec;
+
+    constructor(basePath?: string|string[], configuration?: Configuration) {
+        this.configuration = configuration || new Configuration();
+        if (typeof this.configuration.basePath !== 'string') {
+            const firstBasePath = Array.isArray(basePath) ? basePath[0] : undefined;
+            if (firstBasePath != undefined) {
+                basePath = firstBasePath;
+            }
+
+            if (typeof basePath !== 'string') {
+                basePath = this.basePath;
+            }
+            this.configuration.basePath = basePath;
+        }
+        this.encoder = this.configuration.encoder || new CustomHttpParameterCodec();
+    }
+
+    protected canConsumeForm(consumes: string[]): boolean {
+        return consumes.indexOf('multipart/form-data') !== -1;
+    }
+
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
+        // If the value is an object (but not a Date), recursively add its keys.
+        if (typeof value === 'object' && !(value instanceof Date)) {
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
+        }
+        return this.addToHttpParamsRecursive(httpParams, value, key);
+    }
+
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
+        if (value === null || value === undefined) {
+            return httpParams;
+        }
+        if (typeof value === 'object') {
+            // If JSON format is preferred, key must be provided.
+            if (key != null) {
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
+            }
+            // Otherwise, if it's an array, add each element.
+            if (Array.isArray(value)) {
+                value.forEach(elem => httpParams = this.addToHttpParamsRecursive(httpParams, elem, key));
+            } else if (value instanceof Date) {
+                if (key != null) {
+                    httpParams = httpParams.append(key, value.toISOString());
+                } else {
+                    throw Error("key may not be null if value is Date");
+                }
+            } else {
+                Object.keys(value).forEach(k => {
+                    const paramKey = key ? `${key}.${k}` : k;
+                    httpParams = this.addToHttpParamsRecursive(httpParams, value[k], paramKey);
+                });
+            }
+            return httpParams;
+        } else if (key != null) {
+            return httpParams.append(key, value);
+        }
+        throw Error("key may not be null if value is not object or array");
+    }
+}
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/api.module.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/api.module.ts
new file mode 100644
index 00000000000..58d341fbd2e
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/api.module.ts
@@ -0,0 +1,30 @@
+import { NgModule, ModuleWithProviders, SkipSelf, Optional } from '@angular/core';
+import { Configuration } from './configuration';
+import { HttpClient } from '@angular/common/http';
+
+
+@NgModule({
+  imports:      [],
+  declarations: [],
+  exports:      [],
+  providers: []
+})
+export class ApiModule {
+    public static forRoot(configurationFactory: () => Configuration): ModuleWithProviders<ApiModule> {
+        return {
+            ngModule: ApiModule,
+            providers: [ { provide: Configuration, useFactory: configurationFactory } ]
+        };
+    }
+
+    constructor( @Optional() @SkipSelf() parentModule: ApiModule,
+                 @Optional() http: HttpClient) {
+        if (parentModule) {
+            throw new Error('ApiModule is already loaded. Import in your base AppModule only.');
+        }
+        if (!http) {
+            throw new Error('You need to import the HttpClientModule in your AppModule! \n' +
+            'See also https://github.com/angular/angular/issues/20575');
+        }
+    }
+}
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/api/api.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/api/api.ts
new file mode 100644
index 00000000000..8e76619647f
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/api/api.ts
@@ -0,0 +1,3 @@
+export * from './default.service';
+import { DefaultService } from './default.service';
+export const APIS = [DefaultService];
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/api/default.service.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/api/default.service.ts
new file mode 100644
index 00000000000..0ac4548210b
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/api/default.service.ts
@@ -0,0 +1,95 @@
+/**
+ * deepobject-query
+ *
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+/* tslint:disable:no-unused-variable member-ordering */
+
+import { Inject, Injectable, Optional }                      from '@angular/core';
+import { HttpClient, HttpHeaders, HttpParams,
+         HttpResponse, HttpEvent, HttpParameterCodec, HttpContext 
+        }       from '@angular/common/http';
+import { CustomHttpParameterCodec }                          from '../encoder';
+import { Observable }                                        from 'rxjs';
+
+// @ts-ignore
+import { Car } from '../model/car';
+// @ts-ignore
+import { CarFilter } from '../model/carFilter';
+
+// @ts-ignore
+import { BASE_PATH, COLLECTION_FORMATS }                     from '../variables';
+import { Configuration }                                     from '../configuration';
+import { BaseService } from '../api.base.service';
+
+
+
+@Injectable({
+  providedIn: 'root'
+})
+export class DefaultService extends BaseService {
+
+    constructor(protected httpClient: HttpClient, @Optional() @Inject(BASE_PATH) basePath: string|string[], @Optional() configuration?: Configuration) {
+        super(basePath, configuration);
+    }
+
+    /**
+     * @param filter 
+     * @param observe set whether or not to return the data Observable as the body, response or events. defaults to returning the body.
+     * @param reportProgress flag to report request and response progress.
+     */
+    public getCars(filter?: CarFilter, observe?: 'body', reportProgress?: boolean, options?: {httpHeaderAccept?: 'text/plain', context?: HttpContext, transferCache?: boolean}): Observable<Array<Car>>;
+    public getCars(filter?: CarFilter, observe?: 'response', reportProgress?: boolean, options?: {httpHeaderAccept?: 'text/plain', context?: HttpContext, transferCache?: boolean}): Observable<HttpResponse<Array<Car>>>;
+    public getCars(filter?: CarFilter, observe?: 'events', reportProgress?: boolean, options?: {httpHeaderAccept?: 'text/plain', context?: HttpContext, transferCache?: boolean}): Observable<HttpEvent<Array<Car>>>;
+    public getCars(filter?: CarFilter, observe: any = 'body', reportProgress: boolean = false, options?: {httpHeaderAccept?: 'text/plain', context?: HttpContext, transferCache?: boolean}): Observable<any> {
+
+        let localVarQueryParameters = new HttpParams({encoder: this.encoder});
+        localVarQueryParameters = this.addToHttpParams(localVarQueryParameters,
+          <any>filter, 'filter', true);
+
+        let localVarHeaders = this.defaultHeaders;
+
+        const localVarHttpHeaderAcceptSelected: string | undefined = options?.httpHeaderAccept ?? this.configuration.selectHeaderAccept([
+            'text/plain'
+        ]);
+        if (localVarHttpHeaderAcceptSelected !== undefined) {
+            localVarHeaders = localVarHeaders.set('Accept', localVarHttpHeaderAcceptSelected);
+        }
+
+        const localVarHttpContext: HttpContext = options?.context ?? new HttpContext();
+
+        const localVarTransferCache: boolean = options?.transferCache ?? true;
+
+
+        let responseType_: 'text' | 'json' | 'blob' = 'json';
+        if (localVarHttpHeaderAcceptSelected) {
+            if (localVarHttpHeaderAcceptSelected.startsWith('text')) {
+                responseType_ = 'text';
+            } else if (this.configuration.isJsonMime(localVarHttpHeaderAcceptSelected)) {
+                responseType_ = 'json';
+            } else {
+                responseType_ = 'blob';
+            }
+        }
+
+        let localVarPath = `/car`;
+        const { basePath, withCredentials } = this.configuration;
+        return this.httpClient.request<Array<Car>>('get', `${basePath}${localVarPath}`,
+            {
+                context: localVarHttpContext,
+                params: localVarQueryParameters,
+                responseType: <any>responseType_,
+                ...(withCredentials ? { withCredentials } : {}),
+                headers: localVarHeaders,
+                observe: observe,
+                transferCache: localVarTransferCache,
+                reportProgress: reportProgress
+            }
+        );
+    }
+
+}
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/configuration.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/configuration.ts
new file mode 100644
index 00000000000..2a128451c08
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/configuration.ts
@@ -0,0 +1,184 @@
+import { HttpHeaders, HttpParams, HttpParameterCodec } from '@angular/common/http';
+import { Param } from './param';
+
+export interface ConfigurationParameters {
+    /**
+     *  @deprecated Since 5.0. Use credentials instead
+     */
+    apiKeys?: {[ key: string ]: string};
+    username?: string;
+    password?: string;
+    /**
+     *  @deprecated Since 5.0. Use credentials instead
+     */
+    accessToken?: string | (() => string);
+    basePath?: string;
+    withCredentials?: boolean;
+    /**
+     * Takes care of encoding query- and form-parameters.
+     */
+    encoder?: HttpParameterCodec;
+    /**
+     * Override the default method for encoding path parameters in various
+     * <a href="https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#style-values">styles</a>.
+     * <p>
+     * See {@link README.md} for more details
+     * </p>
+     */
+    encodeParam?: (param: Param) => string;
+    /**
+     * The keys are the names in the securitySchemes section of the OpenAPI
+     * document. They should map to the value used for authentication
+     * minus any standard prefixes such as 'Basic' or 'Bearer'.
+     */
+    credentials?: {[ key: string ]: string | (() => string | undefined)};
+}
+
+export class Configuration {
+    /**
+     *  @deprecated Since 5.0. Use credentials instead
+     */
+    apiKeys?: {[ key: string ]: string};
+    username?: string;
+    password?: string;
+    /**
+     *  @deprecated Since 5.0. Use credentials instead
+     */
+    accessToken?: string | (() => string);
+    basePath?: string;
+    withCredentials?: boolean;
+    /**
+     * Takes care of encoding query- and form-parameters.
+     */
+    encoder?: HttpParameterCodec;
+    /**
+     * Encoding of various path parameter
+     * <a href="https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#style-values">styles</a>.
+     * <p>
+     * See {@link README.md} for more details
+     * </p>
+     */
+    encodeParam: (param: Param) => string;
+    /**
+     * The keys are the names in the securitySchemes section of the OpenAPI
+     * document. They should map to the value used for authentication
+     * minus any standard prefixes such as 'Basic' or 'Bearer'.
+     */
+    credentials: {[ key: string ]: string | (() => string | undefined)};
+
+constructor({ accessToken, apiKeys, basePath, credentials, encodeParam, encoder, password, username, withCredentials }: ConfigurationParameters = {}) {
+        if (apiKeys) {
+            this.apiKeys = apiKeys;
+        }
+        if (username !== undefined) {
+            this.username = username;
+        }
+        if (password !== undefined) {
+            this.password = password;
+        }
+        if (accessToken !== undefined) {
+            this.accessToken = accessToken;
+        }
+        if (basePath !== undefined) {
+            this.basePath = basePath;
+        }
+        if (withCredentials !== undefined) {
+            this.withCredentials = withCredentials;
+        }
+        if (encoder) {
+            this.encoder = encoder;
+        }
+        this.encodeParam = encodeParam ?? (param => this.defaultEncodeParam(param));
+        this.credentials = credentials ?? {};
+    }
+
+    /**
+     * Select the correct content-type to use for a request.
+     * Uses {@link Configuration#isJsonMime} to determine the correct content-type.
+     * If no content type is found return the first found type if the contentTypes is not empty
+     * @param contentTypes - the array of content types that are available for selection
+     * @returns the selected content-type or <code>undefined</code> if no selection could be made.
+     */
+    public selectHeaderContentType (contentTypes: string[]): string | undefined {
+        if (contentTypes.length === 0) {
+            return undefined;
+        }
+
+        const type = contentTypes.find((x: string) => this.isJsonMime(x));
+        if (type === undefined) {
+            return contentTypes[0];
+        }
+        return type;
+    }
+
+    /**
+     * Select the correct accept content-type to use for a request.
+     * Uses {@link Configuration#isJsonMime} to determine the correct accept content-type.
+     * If no content type is found return the first found type if the contentTypes is not empty
+     * @param accepts - the array of content types that are available for selection.
+     * @returns the selected content-type or <code>undefined</code> if no selection could be made.
+     */
+    public selectHeaderAccept(accepts: string[]): string | undefined {
+        if (accepts.length === 0) {
+            return undefined;
+        }
+
+        const type = accepts.find((x: string) => this.isJsonMime(x));
+        if (type === undefined) {
+            return accepts[0];
+        }
+        return type;
+    }
+
+    /**
+     * Check if the given MIME is a JSON MIME.
+     * JSON MIME examples:
+     *   application/json
+     *   application/json; charset=UTF8
+     *   APPLICATION/JSON
+     *   application/vnd.company+json
+     * @param mime - MIME (Multipurpose Internet Mail Extensions)
+     * @return True if the given MIME is JSON, false otherwise.
+     */
+    public isJsonMime(mime: string): boolean {
+        const jsonMime: RegExp = new RegExp('^(application\/json|[^;/ \t]+\/[^;/ \t]+[+]json)[ \t]*(;.*)?$', 'i');
+        return mime !== null && (jsonMime.test(mime) || mime.toLowerCase() === 'application/json-patch+json');
+    }
+
+    public lookupCredential(key: string): string | undefined {
+        const value = this.credentials[key];
+        return typeof value === 'function'
+            ? value()
+            : value;
+    }
+
+    public addCredentialToHeaders(credentialKey: string, headerName: string, headers: HttpHeaders, prefix?: string): HttpHeaders {
+        const value = this.lookupCredential(credentialKey);
+        return value
+            ? headers.set(headerName, (prefix ?? '') + value)
+            : headers;
+    }
+
+    public addCredentialToQuery(credentialKey: string, paramName: string, query: HttpParams): HttpParams {
+        const value = this.lookupCredential(credentialKey);
+        return value
+            ? query.set(paramName, value)
+            : query;
+    }
+
+    private defaultEncodeParam(param: Param): string {
+        // This implementation exists as fallback for missing configuration
+        // and for backwards compatibility to older typescript-angular generator versions.
+        // It only works for the 'simple' parameter style.
+        // Date-handling only works for the 'date-time' format.
+        // All other styles and Date-formats are probably handled incorrectly.
+        //
+        // But: if that's all you need (i.e.: the most common use-case): no need for customization!
+
+        const value = param.dataFormat === 'date-time' && param.value instanceof Date
+            ? (param.value as Date).toISOString()
+            : param.value;
+
+        return encodeURIComponent(String(value));
+    }
+}
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/encoder.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/encoder.ts
new file mode 100644
index 00000000000..138c4d5cf2c
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/encoder.ts
@@ -0,0 +1,20 @@
+import { HttpParameterCodec } from '@angular/common/http';
+
+/**
+ * Custom HttpParameterCodec
+ * Workaround for https://github.com/angular/angular/issues/18261
+ */
+export class CustomHttpParameterCodec implements HttpParameterCodec {
+    encodeKey(k: string): string {
+        return encodeURIComponent(k);
+    }
+    encodeValue(v: string): string {
+        return encodeURIComponent(v);
+    }
+    decodeKey(k: string): string {
+        return decodeURIComponent(k);
+    }
+    decodeValue(v: string): string {
+        return decodeURIComponent(v);
+    }
+}
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/git_push.sh b/samples/client/petstore/typescript-angular-v19/builds/deep-object/git_push.sh
new file mode 100644
index 00000000000..f53a75d4fab
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/git_push.sh
@@ -0,0 +1,57 @@
+#!/bin/sh
+# ref: https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/
+#
+# Usage example: /bin/sh ./git_push.sh wing328 openapi-petstore-perl "minor update" "gitlab.com"
+
+git_user_id=$1
+git_repo_id=$2
+release_note=$3
+git_host=$4
+
+if [ "$git_host" = "" ]; then
+    git_host="github.com"
+    echo "[INFO] No command line input provided. Set \$git_host to $git_host"
+fi
+
+if [ "$git_user_id" = "" ]; then
+    git_user_id="GIT_USER_ID"
+    echo "[INFO] No command line input provided. Set \$git_user_id to $git_user_id"
+fi
+
+if [ "$git_repo_id" = "" ]; then
+    git_repo_id="GIT_REPO_ID"
+    echo "[INFO] No command line input provided. Set \$git_repo_id to $git_repo_id"
+fi
+
+if [ "$release_note" = "" ]; then
+    release_note="Minor update"
+    echo "[INFO] No command line input provided. Set \$release_note to $release_note"
+fi
+
+# Initialize the local directory as a Git repository
+git init
+
+# Adds the files in the local repository and stages them for commit.
+git add .
+
+# Commits the tracked changes and prepares them to be pushed to a remote repository.
+git commit -m "$release_note"
+
+# Sets the new remote
+git_remote=$(git remote)
+if [ "$git_remote" = "" ]; then # git remote not defined
+
+    if [ "$GIT_TOKEN" = "" ]; then
+        echo "[INFO] \$GIT_TOKEN (environment variable) is not set. Using the git credential in your environment."
+        git remote add origin https://${git_host}/${git_user_id}/${git_repo_id}.git
+    else
+        git remote add origin https://${git_user_id}:"${GIT_TOKEN}"@${git_host}/${git_user_id}/${git_repo_id}.git
+    fi
+
+fi
+
+git pull origin master
+
+# Pushes (Forces) the changes in the local repository up to the remote repository
+echo "Git pushing to https://${git_host}/${git_user_id}/${git_repo_id}.git"
+git push origin master 2>&1 | grep -v 'To https'
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/index.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/index.ts
new file mode 100644
index 00000000000..104dd3d21e3
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/index.ts
@@ -0,0 +1,6 @@
+export * from './api/api';
+export * from './model/models';
+export * from './variables';
+export * from './configuration';
+export * from './api.module';
+export * from './param';
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/model/car.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/model/car.ts
new file mode 100644
index 00000000000..fe7337898dc
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/model/car.ts
@@ -0,0 +1,17 @@
+/**
+ * deepobject-query
+ *
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+export interface Car { 
+    id?: number;
+    make?: string;
+    model?: string;
+}
+
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/model/carFilter.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/model/carFilter.ts
new file mode 100644
index 00000000000..9780e598f00
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/model/carFilter.ts
@@ -0,0 +1,16 @@
+/**
+ * deepobject-query
+ *
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+export interface CarFilter { 
+    make?: string;
+    model?: string;
+}
+
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/model/models.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/model/models.ts
new file mode 100644
index 00000000000..b249b9550ab
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/model/models.ts
@@ -0,0 +1,2 @@
+export * from './car';
+export * from './carFilter';
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/ng-package.json b/samples/client/petstore/typescript-angular-v19/builds/deep-object/ng-package.json
new file mode 100644
index 00000000000..3b17900dc9c
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/ng-package.json
@@ -0,0 +1,6 @@
+{
+  "$schema": "./node_modules/ng-packagr/ng-package.schema.json",
+  "lib": {
+    "entryFile": "index.ts"
+  }
+}
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/package.json b/samples/client/petstore/typescript-angular-v19/builds/deep-object/package.json
new file mode 100644
index 00000000000..71f619b0dea
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/package.json
@@ -0,0 +1,33 @@
+{
+  "name": "sample-angular-19-0-0-deep-object",
+  "version": "1.0.0",
+  "description": "OpenAPI client for sample-angular-19-0-0-deep-object",
+  "author": "OpenAPI-Generator Contributors",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/GIT_USER_ID/GIT_REPO_ID.git"
+  },
+  "keywords": [
+    "openapi-client",
+    "openapi-generator"
+  ],
+  "license": "Unlicense",
+  "scripts": {
+    "build": "ng-packagr -p ng-package.json"
+  },
+  "peerDependencies": {
+    "@angular/core": "^19.0.0",
+    "rxjs": "^7.4.0"
+  },
+  "devDependencies": {
+    "@angular/common": "^19.0.0",
+    "@angular/compiler": "^19.0.0",
+    "@angular/compiler-cli": "^19.0.0",
+    "@angular/core": "^19.0.0",
+    "@angular/platform-browser": "^19.0.0",
+    "ng-packagr": "^19.0.0",
+    "reflect-metadata": "^0.1.3",
+    "rxjs": "^7.4.0",
+    "typescript": ">=5.5.0 <5.7.0",
+    "zone.js": "^0.15.0"
+  }}
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/param.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/param.ts
new file mode 100644
index 00000000000..78a2d20a643
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/param.ts
@@ -0,0 +1,69 @@
+/**
+ * Standard parameter styles defined by OpenAPI spec
+ */
+export type StandardParamStyle =
+  | 'matrix'
+  | 'label'
+  | 'form'
+  | 'simple'
+  | 'spaceDelimited'
+  | 'pipeDelimited'
+  | 'deepObject'
+  ;
+
+/**
+ * The OpenAPI standard {@link StandardParamStyle}s may be extended by custom styles by the user.
+ */
+export type ParamStyle = StandardParamStyle | string;
+
+/**
+ * Standard parameter locations defined by OpenAPI spec
+ */
+export type ParamLocation = 'query' | 'header' | 'path' | 'cookie';
+
+/**
+ * Standard types as defined in <a href="https://swagger.io/specification/#data-types">OpenAPI Specification: Data Types</a>
+ */
+export type StandardDataType =
+  | "integer"
+  | "number"
+  | "boolean"
+  | "string"
+  | "object"
+  | "array"
+  ;
+
+/**
+ * Standard {@link DataType}s plus your own types/classes.
+ */
+export type DataType = StandardDataType | string;
+
+/**
+ * Standard formats as defined in <a href="https://swagger.io/specification/#data-types">OpenAPI Specification: Data Types</a>
+ */
+export type StandardDataFormat =
+  | "int32"
+  | "int64"
+  | "float"
+  | "double"
+  | "byte"
+  | "binary"
+  | "date"
+  | "date-time"
+  | "password"
+  ;
+
+export type DataFormat = StandardDataFormat | string;
+
+/**
+ * The parameter to encode.
+ */
+export interface Param {
+  name: string;
+  value: unknown;
+  in: ParamLocation;
+  style: ParamStyle,
+  explode: boolean;
+  dataType: DataType;
+  dataFormat: DataFormat | undefined;
+}
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/tsconfig.json b/samples/client/petstore/typescript-angular-v19/builds/deep-object/tsconfig.json
new file mode 100644
index 00000000000..b3049e9eee6
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/tsconfig.json
@@ -0,0 +1,29 @@
+{
+    "compilerOptions": {
+        "emitDecoratorMetadata": true,
+        "experimentalDecorators": true,
+        "noImplicitAny": false,
+        "target": "es6",
+        "module": "es6",
+        "moduleResolution": "node",
+        "removeComments": true,
+        "strictNullChecks": true,
+        "exactOptionalPropertyTypes": true,
+        "sourceMap": true,
+        "outDir": "./dist",
+        "noLib": false,
+        "declaration": true,
+        "lib": [ "es6", "dom" ],
+        "typeRoots": [
+            "node_modules/@types"
+        ]
+    },
+    "exclude": [
+        "node_modules",
+        "dist"
+    ],
+    "filesGlob": [
+        "./model/*.ts",
+        "./api/*.ts"
+    ]
+}
diff --git a/samples/client/petstore/typescript-angular-v19/builds/deep-object/variables.ts b/samples/client/petstore/typescript-angular-v19/builds/deep-object/variables.ts
new file mode 100644
index 00000000000..6fe58549f39
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/builds/deep-object/variables.ts
@@ -0,0 +1,9 @@
+import { InjectionToken } from '@angular/core';
+
+export const BASE_PATH = new InjectionToken<string>('basePath');
+export const COLLECTION_FORMATS = {
+    'csv': ',',
+    'tsv': '   ',
+    'ssv': ' ',
+    'pipes': '|'
+}
diff --git a/samples/client/petstore/typescript-angular-v19/builds/default/api.base.service.ts b/samples/client/petstore/typescript-angular-v19/builds/default/api.base.service.ts
index c81bd085271..e2e57d08322 100644
--- a/samples/client/petstore/typescript-angular-v19/builds/default/api.base.service.ts
+++ b/samples/client/petstore/typescript-angular-v19/builds/default/api.base.service.ts
@@ -37,22 +37,27 @@ export class BaseService {
         return consumes.indexOf('multipart/form-data') !== -1;
     }
 
-    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string): HttpParams {
+    protected addToHttpParams(httpParams: HttpParams, value: any, key?: string, isDeep: boolean = false): HttpParams {
         // If the value is an object (but not a Date), recursively add its keys.
         if (typeof value === 'object' && !(value instanceof Date)) {
-            return this.addToHttpParamsRecursive(httpParams, value);
+            return this.addToHttpParamsRecursive(httpParams, value, isDeep ? key : undefined, isDeep);
         }
         return this.addToHttpParamsRecursive(httpParams, value, key);
     }
 
-    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string): HttpParams {
+    protected addToHttpParamsRecursive(httpParams: HttpParams, value?: any, key?: string, isDeep: boolean = false): HttpParams {
         if (value === null || value === undefined) {
             return httpParams;
         }
         if (typeof value === 'object') {
             // If JSON format is preferred, key must be provided.
             if (key != null) {
-                return httpParams.append(key, JSON.stringify(value));
+                return isDeep
+                    ? Object.keys(value as Record<string, any>).reduce(
+                        (hp, k) => hp.append(`${key}[${k}]`, value[k]),
+                        httpParams,
+                    )
+                    : httpParams.append(key, JSON.stringify(value));
             }
             // Otherwise, if it's an array, add each element.
             if (Array.isArray(value)) {
diff --git a/samples/client/petstore/typescript-angular-v19/src/api.spec.ts b/samples/client/petstore/typescript-angular-v19/src/api.spec.ts
new file mode 100644
index 00000000000..1b8efe77d76
--- /dev/null
+++ b/samples/client/petstore/typescript-angular-v19/src/api.spec.ts
@@ -0,0 +1,24 @@
+import { TestBed } from '@angular/core/testing'
+import { provideHttpClient } from '@angular/common/http'
+import { HttpTestingController, provideHttpClientTesting } from '@angular/common/http/testing'
+import { DefaultService } from '@swagger/typescript-angular-deepobject'
+
+describe('DeepObject Query Param testing', () => {
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      providers: [
+        provideHttpClient(),
+        provideHttpClientTesting(),
+        DefaultService,
+      ],
+    }).compileComponents();
+  });
+
+  it('should generate the deepObject query with the correct parameters', async () => {
+    const httpTesting = TestBed.inject(HttpTestingController);
+    const carService = TestBed.inject(DefaultService)
+    carService.getCars({ make: 'bmw', model: '319' }).subscribe()
+    const req = httpTesting.expectOne('http://localhost/car?filter%5Bmake%5D=bmw&filter%5Bmodel%5D=319')
+    expect(req.request.method).toEqual('GET')
+  });
+});
\ No newline at end of file
diff --git a/samples/client/petstore/typescript-angular-v19/src/app/app.component.spec.ts b/samples/client/petstore/typescript-angular-v19/src/app/app.component.spec.ts
index 18272ecef2a..3098fb8fddb 100644
--- a/samples/client/petstore/typescript-angular-v19/src/app/app.component.spec.ts
+++ b/samples/client/petstore/typescript-angular-v19/src/app/app.component.spec.ts
@@ -39,4 +39,4 @@ describe('AppComponent', () => {
     fixture.detectChanges();
     expect(fixture.componentInstance.pets![0]).toEqual(pet)
   });
-});
+});
\ No newline at end of file
diff --git a/samples/client/petstore/typescript-angular-v19/tsconfig.json b/samples/client/petstore/typescript-angular-v19/tsconfig.json
index 72afd12ed3d..709258e9d55 100644
--- a/samples/client/petstore/typescript-angular-v19/tsconfig.json
+++ b/samples/client/petstore/typescript-angular-v19/tsconfig.json
@@ -18,7 +18,8 @@
     "target": "ES2022",
     "module": "ES2022",
     "paths": {
-      "@swagger/typescript-angular-petstore": ["./builds/default"]
+      "@swagger/typescript-angular-petstore": ["./builds/default"],
+      "@swagger/typescript-angular-deepobject": ["./builds/deep-object"]
     }
   },
   "angularCompilerOptions": {