diff --git a/.prettierignore b/.prettierignore
new file mode 100644
index 00000000..c24b7182
--- /dev/null
+++ b/.prettierignore
@@ -0,0 +1 @@
+src/templates
diff --git a/src/index.ts b/src/index.ts
index b59d8f46..e25140d7 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -24,9 +24,9 @@ export enum HttpClient {
  * given language it will generate the client, including the typed models, validation schemas,
  * service layer, etc.
  * @param input The relative location of the OpenAPI spec.
- * @param output The relative location of the output directory
- * @param language: The language that should be generated (Typescript or Javascript)
- * @param httpClient: The selected httpClient (fetch or XHR)
+ * @param output The relative location of the output directory.
+ * @param language: The language that should be generated (Typescript or Javascript).
+ * @param httpClient: The selected httpClient (fetch or XHR).
  */
 export function generate(input: string, output: string, language: Language = Language.TYPESCRIPT, httpClient: HttpClient = HttpClient.FETCH): void {
     const inputPath = path.resolve(process.cwd(), input);
@@ -52,13 +52,13 @@ export function generate(input: string, output: string, language: Language = Lan
                 // Generate and write version 2 client
                 if (openApiVersion === OpenApiVersion.V2) {
                     const clientV2 = parseV2(openApi);
-                    writeClient(clientV2, language, templates, outputPath);
+                    writeClient(clientV2, language, httpClient, templates, outputPath);
                 }
 
                 // Generate and write version 3 client
                 if (openApiVersion === OpenApiVersion.V3) {
                     const clientV3 = parseV3(openApi);
-                    writeClient(clientV3, language, templates, outputPath);
+                    writeClient(clientV3, language, httpClient, templates, outputPath);
                 }
         }
     } catch (e) {
diff --git a/src/templates/typescript/core/ApiError.ts b/src/templates/typescript/core/ApiError.ts
index a5d86214..375350de 100644
--- a/src/templates/typescript/core/ApiError.ts
+++ b/src/templates/typescript/core/ApiError.ts
@@ -7,6 +7,7 @@ import { isSuccess } from './isSuccess';
 import { Result } from './Result';
 
 export class ApiError extends Error {
+
     public readonly url: string;
     public readonly status: number;
     public readonly statusText: string;
@@ -41,20 +42,13 @@ export namespace ApiError {
  */
 export function catchGenericError(result: Result): void {
     switch (result.status) {
-        case 400:
-            throw new ApiError(result, ApiError.Message.BAD_REQUEST);
-        case 401:
-            throw new ApiError(result, ApiError.Message.UNAUTHORIZED);
-        case 403:
-            throw new ApiError(result, ApiError.Message.FORBIDDEN);
-        case 404:
-            throw new ApiError(result, ApiError.Message.NOT_FOUND);
-        case 500:
-            throw new ApiError(result, ApiError.Message.INTERNAL_SERVER_ERROR);
-        case 502:
-            throw new ApiError(result, ApiError.Message.BAD_GATEWAY);
-        case 503:
-            throw new ApiError(result, ApiError.Message.SERVICE_UNAVAILABLE);
+        case 400: throw new ApiError(result, ApiError.Message.BAD_REQUEST);
+        case 401: throw new ApiError(result, ApiError.Message.UNAUTHORIZED);
+        case 403: throw new ApiError(result, ApiError.Message.FORBIDDEN);
+        case 404: throw new ApiError(result, ApiError.Message.NOT_FOUND);
+        case 500: throw new ApiError(result, ApiError.Message.INTERNAL_SERVER_ERROR);
+        case 502: throw new ApiError(result, ApiError.Message.BAD_GATEWAY);
+        case 503: throw new ApiError(result, ApiError.Message.SERVICE_UNAVAILABLE);
     }
 
     if (!isSuccess(result.status)) {
diff --git a/src/templates/typescript/core/RequestOptions.ts b/src/templates/typescript/core/RequestOptions.ts
index 7816bf98..08c22fb5 100644
--- a/src/templates/typescript/core/RequestOptions.ts
+++ b/src/templates/typescript/core/RequestOptions.ts
@@ -4,6 +4,7 @@
 /* prettier-ignore */
 
 export interface RequestOptions {
+    type: 'fetch' | 'xhr';
     method: string;
     path: string;
     headers?: { [key: string]: any };
diff --git a/src/templates/typescript/core/request.ts b/src/templates/typescript/core/request.ts
index 84ce4eb8..1c1c2657 100644
--- a/src/templates/typescript/core/request.ts
+++ b/src/templates/typescript/core/request.ts
@@ -8,6 +8,7 @@ import { getQueryString } from './getQueryString';
 import { OpenAPI } from './OpenAPI';
 import { RequestOptions } from './RequestOptions';
 import { requestUsingFetch } from './requestUsingFetch';
+import { requestUsingXHR } from './requestUsingXHR';
 import { Result } from './Result';
 
 /**
@@ -16,6 +17,7 @@ import { Result } from './Result';
  * @returns Result object (see above)
  */
 export async function request<T = any>(options: Readonly<RequestOptions>): Promise<Result<T>> {
+
     // Create the request URL
     let url = `${OpenAPI.BASE}${options.path}`;
 
@@ -46,6 +48,7 @@ export async function request<T = any>(options: Readonly<RequestOptions>): Promi
     if (options.formData) {
         request.body = getFormData(options.formData);
     } else if (options.body) {
+
         // If this is blob data, then pass it directly to the body and set content type.
         // Otherwise we just convert request data to JSON string (needed for fetch api)
         if (options.body instanceof Blob) {
@@ -60,7 +63,12 @@ export async function request<T = any>(options: Readonly<RequestOptions>): Promi
     }
 
     try {
-        return await requestUsingFetch<T>(url, request);
+        switch (options.type) {
+            case 'fetch':
+                return await requestUsingFetch<T>(url, request);
+            case 'xhr':
+                return await requestUsingXHR<T>(url, request);
+        }
     } catch (error) {
         return {
             url,
diff --git a/src/templates/typescript/core/requestUsingFetch.ts b/src/templates/typescript/core/requestUsingFetch.ts
index ef3a1c5a..27d217c9 100644
--- a/src/templates/typescript/core/requestUsingFetch.ts
+++ b/src/templates/typescript/core/requestUsingFetch.ts
@@ -13,6 +13,7 @@ import { Result } from './Result';
  * @param request The request object, containing method, headers, body, etc.
  */
 export async function requestUsingFetch<T = any>(url: string, request: Readonly<RequestInit>): Promise<Result<T>> {
+
     // Fetch response using fetch API.
     const response = await fetch(url, request);
 
diff --git a/src/templates/typescript/core/requestUsingXHR.ts b/src/templates/typescript/core/requestUsingXHR.ts
index acf30e30..79a74d1d 100644
--- a/src/templates/typescript/core/requestUsingXHR.ts
+++ b/src/templates/typescript/core/requestUsingXHR.ts
@@ -31,6 +31,7 @@ export async function requestUsingXHR<T = any>(url: string, request: Readonly<Re
         // Register the readystate handler, this will fire when the request is done.
         xhr.onreadystatechange = () => {
             if (xhr.readyState === XMLHttpRequest.DONE) {
+
                 // Create result object.
                 const result: Result = {
                     url,
diff --git a/src/templates/typescript/service.hbs b/src/templates/typescript/service.hbs
index 03993de6..b41d59c1 100644
--- a/src/templates/typescript/service.hbs
+++ b/src/templates/typescript/service.hbs
@@ -14,6 +14,7 @@ import { OpenAPI } from '../core/OpenAPI';
 import { Result } from '../core/Result';
 
 export class {{{name}}} {
+
     {{#each operations}}
     /**
     {{#if deprecated}}
@@ -30,10 +31,12 @@ export class {{{name}}} {
      * @param {{{name}}} {{{description}}}
     {{/each}}
     {{/if}}
+     * @return {{{result}}}
      */
     public static async {{{name}}}({{#each parameters}}{{{name}}}{{#unless required}}?{{/unless}}: {{{type}}}{{#if nullable}} | null{{/if}}{{#unless @last}}, {{/unless}}{{/each}}): Promise<{{{result}}}> {
 
         const result: Result<{{{result}}}> = await request({
+            type: '{{{../httpClient}}}',
             method: '{{{method}}}',
             path: `{{{path}}}`,
             {{#if parametersHeader}}
diff --git a/src/utils/readHandlebarsTemplates.ts b/src/utils/readHandlebarsTemplates.ts
index 18555d83..1c83c365 100644
--- a/src/utils/readHandlebarsTemplates.ts
+++ b/src/utils/readHandlebarsTemplates.ts
@@ -18,11 +18,13 @@ export interface Templates {
 export function readHandlebarsTemplates(language: Language): Templates {
     try {
         registerHandlebarHelpers();
+
         const templates: Templates = {
             index: readHandlebarsTemplate(path.resolve(__dirname, `../../src/templates/${language}/index.hbs`)),
             model: readHandlebarsTemplate(path.resolve(__dirname, `../../src/templates/${language}/model.hbs`)),
             service: readHandlebarsTemplate(path.resolve(__dirname, `../../src/templates/${language}/service.hbs`)),
         };
+
         Handlebars.registerPartial({
             exportGeneric: readHandlebarsTemplate(path.resolve(__dirname, `../../src/templates/${language}/exportGeneric.hbs`)),
             exportReference: readHandlebarsTemplate(path.resolve(__dirname, `../../src/templates/${language}/exportReference.hbs`)),
@@ -45,6 +47,7 @@ export function readHandlebarsTemplates(language: Language): Templates {
             typeForReference: readHandlebarsTemplate(path.resolve(__dirname, `../../src/templates/${language}/typeForReference.hbs`)),
             typeForGeneric: readHandlebarsTemplate(path.resolve(__dirname, `../../src/templates/${language}/typeForGeneric.hbs`)),
         });
+
         return templates;
     } catch (e) {
         throw e;
diff --git a/src/utils/writeClient.ts b/src/utils/writeClient.ts
index 20c42e8e..8e9e449e 100644
--- a/src/utils/writeClient.ts
+++ b/src/utils/writeClient.ts
@@ -6,18 +6,19 @@ import * as mkdirp from 'mkdirp';
 import * as rimraf from 'rimraf';
 import { Templates } from './readHandlebarsTemplates';
 import { writeClientIndex } from './writeClientIndex';
-import { Language } from '../index';
+import { HttpClient, Language } from '../index';
 import * as fs from 'fs';
 import * as glob from 'glob';
 
 /**
- * Write our OpenAPI client, using the given templates at the given output path
- * @param client: Client object with all the models, services, etc.
- * @param language: The output language (Typescript or javascript).
- * @param templates: Templates wrapper with all loaded Handlebars templates.
+ * Write our OpenAPI client, using the given templates at the given output path.
+ * @param client Client object with all the models, services, etc.
+ * @param language The language that should be generated (Typescript or Javascript).
+ * @param httpClient The selected httpClient (fetch or XHR).
+ * @param templates Templates wrapper with all loaded Handlebars templates.
  * @param outputPath
  */
-export function writeClient(client: Client, language: Language, templates: Templates, outputPath: string): void {
+export function writeClient(client: Client, language: Language, httpClient: HttpClient, templates: Templates, outputPath: string): void {
     const outputPathCore = path.resolve(outputPath, 'core');
     const outputPathModels = path.resolve(outputPath, 'models');
     const outputPathServices = path.resolve(outputPath, 'services');
@@ -52,8 +53,8 @@ export function writeClient(client: Client, language: Language, templates: Templ
     // Write the client files
     try {
         writeClientIndex(client, language, templates, outputPath);
-        writeClientModels(client.models, language, templates, outputPathModels);
-        writeClientServices(client.services, language, templates, outputPathServices);
+        writeClientModels(client.models, language, httpClient, templates, outputPathModels);
+        writeClientServices(client.services, language, httpClient, templates, outputPathServices);
     } catch (e) {
         throw e;
     }
diff --git a/src/utils/writeClientIndex.ts b/src/utils/writeClientIndex.ts
index 80a7e793..902c52a4 100644
--- a/src/utils/writeClientIndex.ts
+++ b/src/utils/writeClientIndex.ts
@@ -11,10 +11,10 @@ import { Templates } from './readHandlebarsTemplates';
  * Generate the OpenAPI client index file using the Handlebar template and write it to disk.
  * The index file just contains all the exports you need to use the client as a standalone
  * library. But yuo can also import individual models and services directly.
- * @param client: Client object, containing, models, schemas and services.
- * @param language: The output language (Typescript or javascript).
- * @param templates: The loaded handlebar templates.
- * @param outputPath:
+ * @param client Client object, containing, models, schemas and services.
+ * @param language The output language (Typescript or javascript).
+ * @param templates The loaded handlebar templates.
+ * @param outputPath
  */
 export function writeClientIndex(client: Client, language: Language, templates: Templates, outputPath: string): void {
     const fileName = getFileName('index', language);
diff --git a/src/utils/writeClientModels.spec.ts b/src/utils/writeClientModels.spec.ts
index 740e44bf..6bb2af26 100644
--- a/src/utils/writeClientModels.spec.ts
+++ b/src/utils/writeClientModels.spec.ts
@@ -1,7 +1,7 @@
 import { writeClientModels } from './writeClientModels';
 import * as fs from 'fs';
 import { Model } from '../client/interfaces/Model';
-import { Language } from '../index';
+import { HttpClient, Language } from '../index';
 import { Templates } from './readHandlebarsTemplates';
 
 jest.mock('fs');
@@ -33,7 +33,7 @@ describe('writeClientModels', () => {
             model: () => 'dummy',
             service: () => 'dummy',
         };
-        writeClientModels(models, Language.TYPESCRIPT, templates, '/');
+        writeClientModels(models, Language.TYPESCRIPT, HttpClient.FETCH, templates, '/');
         expect(fsWriteFileSync).toBeCalledWith('/Item.ts', 'dummy');
     });
 });
diff --git a/src/utils/writeClientModels.ts b/src/utils/writeClientModels.ts
index 6d7c108c..2e70d7a9 100644
--- a/src/utils/writeClientModels.ts
+++ b/src/utils/writeClientModels.ts
@@ -1,7 +1,7 @@
 import * as fs from 'fs';
 import { Model } from '../client/interfaces/Model';
 import * as path from 'path';
-import { Language } from '../index';
+import { HttpClient, Language } from '../index';
 import { getFileName } from './getFileName';
 import { exportModel } from './exportModel';
 import { Templates } from './readHandlebarsTemplates';
@@ -9,17 +9,22 @@ import { format } from './format';
 
 /**
  * Generate Models using the Handlebar template and write to disk.
- * @param models: Array of Models to write.
- * @param language: The output language (Typescript or javascript).
- * @param templates: The loaded handlebar templates.
- * @param outputPath:
+ * @param models Array of Models to write.
+ * @param language The output language (Typescript or javascript).
+ * @param httpClient The selected httpClient (fetch or XHR).
+ * @param templates The loaded handlebar templates.
+ * @param outputPath
  */
-export function writeClientModels(models: Map<string, Model>, language: Language, templates: Templates, outputPath: string): void {
+export function writeClientModels(models: Map<string, Model>, language: Language, httpClient: HttpClient, templates: Templates, outputPath: string): void {
     models.forEach(model => {
         const fileName = getFileName(model.name, language);
         try {
             const templateData = exportModel(model);
-            const templateResult = templates.model(templateData);
+            const templateResult = templates.model({
+                language,
+                httpClient,
+                ...templateData,
+            });
             fs.writeFileSync(path.resolve(outputPath, fileName), format(templateResult));
         } catch (e) {
             throw new Error(`Could not write model: "${fileName}"`);
diff --git a/src/utils/writeClientServices.spec.ts b/src/utils/writeClientServices.spec.ts
index 6b3a8833..cf16df65 100644
--- a/src/utils/writeClientServices.spec.ts
+++ b/src/utils/writeClientServices.spec.ts
@@ -1,7 +1,7 @@
 import { writeClientServices } from './writeClientServices';
 import * as fs from 'fs';
 import { Service } from '../client/interfaces/Service';
-import { Language } from '../index';
+import { HttpClient, Language } from '../index';
 import { Templates } from './readHandlebarsTemplates';
 
 jest.mock('fs');
@@ -21,7 +21,7 @@ describe('writeClientServices', () => {
             model: () => 'dummy',
             service: () => 'dummy',
         };
-        writeClientServices(services, Language.TYPESCRIPT, templates, '/');
+        writeClientServices(services, Language.TYPESCRIPT, HttpClient.FETCH, templates, '/');
         expect(fsWriteFileSync).toBeCalledWith('/Item.ts', 'dummy');
     });
 });
diff --git a/src/utils/writeClientServices.ts b/src/utils/writeClientServices.ts
index 63efd5e8..d8f865f7 100644
--- a/src/utils/writeClientServices.ts
+++ b/src/utils/writeClientServices.ts
@@ -1,7 +1,7 @@
 import * as fs from 'fs';
 import * as path from 'path';
 import { Service } from '../client/interfaces/Service';
-import { Language } from '../index';
+import { HttpClient, Language } from '../index';
 import { getFileName } from './getFileName';
 import { exportService } from './exportService';
 import { Templates } from './readHandlebarsTemplates';
@@ -9,17 +9,22 @@ import { format } from './format';
 
 /**
  * Generate Services using the Handlebar template and write to disk.
- * @param services: Array of Services to write.
- * @param language: The output language (Typescript or javascript).
- * @param templates: The loaded handlebar templates.
- * @param outputPath:
+ * @param services Array of Services to write.
+ * @param language The output language (Typescript or javascript).
+ * @param httpClient The selected httpClient (fetch or XHR).
+ * @param templates The loaded handlebar templates.
+ * @param outputPath
  */
-export function writeClientServices(services: Map<string, Service>, language: Language, templates: Templates, outputPath: string): void {
+export function writeClientServices(services: Map<string, Service>, language: Language, httpClient: HttpClient, templates: Templates, outputPath: string): void {
     services.forEach(service => {
         const fileName = getFileName(service.name, language);
         try {
             const templateData = exportService(service);
-            const templateResult = templates.service(templateData);
+            const templateResult = templates.service({
+                language,
+                httpClient,
+                ...templateData,
+            });
             fs.writeFileSync(path.resolve(outputPath, fileName), format(templateResult));
         } catch (e) {
             throw new Error(`Could not write service: "${fileName}"`);
diff --git a/test/index.js b/test/index.js
index c8c07def..81e21875 100755
--- a/test/index.js
+++ b/test/index.js
@@ -25,12 +25,12 @@ OpenAPI.generate(
 //     OpenAPI.HttpClient.FETCH,
 // );
 //
-OpenAPI.generate(
-    './test/mock/v2/test-sites.json',
-    './test/tmp/v2/ts/test-sites',
-    OpenAPI.Language.TYPESCRIPT,
-    OpenAPI.HttpClient.FETCH,
-);
+// OpenAPI.generate(
+//     './test/mock/v2/test-sites.json',
+//     './test/tmp/v2/ts/test-sites',
+//     OpenAPI.Language.TYPESCRIPT,
+//     OpenAPI.HttpClient.FETCH,
+// );
 //
 // OpenAPI.generate(
 //     './test/mock/v2/test-petstore.yaml',
diff --git a/test/mock/v2/spec.json b/test/mock/v2/spec.json
index 5108c7d3..9908d14c 100644
--- a/test/mock/v2/spec.json
+++ b/test/mock/v2/spec.json
@@ -10,6 +10,14 @@
         "http"
     ],
     "paths": {
+        "/api/v{api-version}/dummy": {
+            "get": {
+                "tags": [
+                    "Service"
+                ],
+                "operationId": "GetCallWithoutParametersAndResponse"
+            }
+        }
     },
     "definitions": {
         "SimpleInteger": {