diff --git a/Runware/Runware-base.ts b/Runware/Runware-base.ts
index 86f20f0..edddb53 100644
--- a/Runware/Runware-base.ts
+++ b/Runware/Runware-base.ts
@@ -33,6 +33,7 @@ import {
   TImageMasking,
   TModelSearchResponse,
   TServerError,
+  IOutputType,
 } from "./types";
 import {
   BASE_RUNWARE_URLS,
@@ -144,8 +145,8 @@ export class RunwareBase {
       const arrayErrors = (msg as any)?.[0]?.errors
         ? (msg as any)?.[0]?.errors
         : Array.isArray(msg?.errors)
-        ? msg.errors
-        : [msg.errors];
+          ? msg.errors
+          : [msg.errors];
 
       const filteredMessage = arrayMessage.filter(
         (v) => (v?.taskUUID || v?.taskType) === taskUUID
@@ -372,7 +373,7 @@ export class RunwareBase {
     });
   }
 
-  async requestImages(
+  async requestImages<TOutput extends IOutputType = any, HasCost extends boolean = false>(
     {
       outputType,
       outputFormat,
@@ -407,10 +408,10 @@ export class RunwareBase {
       ipAdapters,
       outpaint,
     }: // imageSize,
-    // gScale,
-    IRequestImage,
+      // gScale,
+      IRequestImage<TOutput, HasCost>,
     moreOptions?: Record<string, any>
-  ): Promise<ITextToImage[] | undefined> {
+  ): Promise<ITextToImage<TOutput, HasCost>[] | undefined> {
     let lis: any = undefined;
     let requestObject: Record<string, any> | undefined = undefined;
     let taskUUIDs: string[] = [];
@@ -661,12 +662,12 @@ export class RunwareBase {
     }
   };
 
-  requestImageToText = async ({
+  requestImageToText = async <HasCost extends boolean = false>({
     inputImage,
     includeCost,
     customTaskUUID,
     retry,
-  }: IRequestImageToText): Promise<IImageToText> => {
+  }: IRequestImageToText<HasCost>): Promise<IImageToText<HasCost>> => {
     const totalRetry = retry || this._globalMaxRetries;
     let lis: any = undefined;
 
@@ -731,9 +732,9 @@ export class RunwareBase {
     }
   };
 
-  removeImageBackground = async (
-    payload: IRemoveImageBackground
-  ): Promise<IRemoveImage> => {
+  removeImageBackground = async<TOutput extends IOutputType = any, HasCost extends boolean = false>(
+    payload: IRemoveImageBackground<TOutput, HasCost>
+  ): Promise<IRemoveImage<TOutput, HasCost>> => {
     return this.baseSingleRequest({
       payload: {
         ...payload,
@@ -830,7 +831,7 @@ export class RunwareBase {
     // }
   };
 
-  upscaleGan = async ({
+  upscaleGan = async<TOutput extends IOutputType = any, HasCost extends boolean = false>({
     inputImage,
     upscaleFactor,
     outputType,
@@ -839,7 +840,7 @@ export class RunwareBase {
     outputQuality,
     customTaskUUID,
     retry,
-  }: IUpscaleGan): Promise<IImage> => {
+  }: IUpscaleGan<TOutput, HasCost>): Promise<IImage<TOutput, HasCost>> => {
     const totalRetry = retry || this._globalMaxRetries;
     let lis: any = undefined;
 
@@ -903,14 +904,14 @@ export class RunwareBase {
     }
   };
 
-  enhancePrompt = async ({
+  enhancePrompt = async<HasCost extends boolean = false> ({
     prompt,
     promptMaxLength = 380,
     promptVersions = 1,
     includeCost,
     customTaskUUID,
     retry,
-  }: IPromptEnhancer): Promise<IEnhancedPrompt[]> => {
+  }: IPromptEnhancer<HasCost>): Promise<IEnhancedPrompt<HasCost>[]> => {
     const totalRetry = retry || this._globalMaxRetries;
     let lis: any = undefined;
 
@@ -1217,7 +1218,7 @@ export class RunwareBase {
         throw this._connectionError;
       }
 
-      return new Promise((resolve, reject) => {
+      return new Promise<void>((resolve, reject) => {
         //  const isConnected =
         let retry = 0;
         const MAX_RETRY = 30;
@@ -1257,7 +1258,7 @@ export class RunwareBase {
 
               if (hasConnected) {
                 clearAllIntervals();
-                resolve(true);
+                resolve();
               } else if (retry >= MAX_RETRY) {
                 clearAllIntervals();
                 reject(new Error("Retry timed out"));
@@ -1279,7 +1280,7 @@ export class RunwareBase {
 
           if (hasConnected) {
             clearAllIntervals();
-            resolve(true);
+            resolve();
             return;
           }
           if (!!this.isInvalidAPIKey()) {
diff --git a/Runware/types.ts b/Runware/types.ts
index 1a0b755..ad48249 100644
--- a/Runware/types.ts
+++ b/Runware/types.ts
@@ -34,23 +34,41 @@ export type RunwareBaseType = {
 export type IOutputType = "base64Data" | "dataURI" | "URL";
 export type IOutputFormat = "JPG" | "PNG" | "WEBP";
 
-export interface IImage {
+
+interface IOutputTypeFieldBase64 {
+  imageBase64Data: string
+}
+
+interface IOutputTypeFieldUrl {
+  imageURL: string;
+}
+
+interface IOutputTypeFieldUri {
+  imageDataURI: string;
+}
+
+type OutputTypeFieldMap = {
+  base64Data: IOutputTypeFieldBase64;
+  dataURI: IOutputTypeFieldUri;
+  URL: IOutputTypeFieldUrl;
+};
+
+type CostField<Value extends boolean> = Value extends true ? { cost: number } : {}
+
+export type IImage<TOutput extends IOutputType = any, HasCost extends boolean = false> = {
   taskType: ETaskType;
   imageUUID: string;
   inputImageUUID?: string;
   taskUUID: string;
-  imageURL?: string;
-  imageBase64Data?: string;
-  imageDataURI?: string;
   NSFWContent?: boolean;
-  cost?: number;
   seed: number;
-}
+} & OutputTypeFieldMap[TOutput] & CostField<HasCost>
 
-export interface ITextToImage extends IImage {
+export type ITextToImage<TOutput extends IOutputType = any, HasCost extends boolean = false> = {
   positivePrompt?: string;
   negativePrompt?: string;
-}
+} & IImage<TOutput> & CostField<HasCost>
+
 export interface IControlNetImage {
   taskUUID: string;
   inputImageUUID: string;
@@ -131,8 +149,8 @@ export interface IError {
 
 export type TPromptWeighting = "compel" | "sdEmbeds";
 
-export interface IRequestImage {
-  outputType?: IOutputType;
+export interface IRequestImage<TOutput extends IOutputType = any, HasCost extends boolean = false> {
+  outputType?: TOutput;
   outputFormat?: IOutputFormat;
   uploadEndpoint?: string;
   checkNSFW?: boolean;
@@ -156,7 +174,7 @@ export interface IRequestImage {
   usePromptWeighting?: boolean;
   promptWeighting?: TPromptWeighting;
   numberResults?: number; // default to 1
-  includeCost?: boolean;
+  includeCost?: HasCost;
   outputQuality?: number;
 
   controlNet?: IControlNet[];
@@ -195,21 +213,20 @@ export interface IRefiner {
   startStep?: number;
   startStepPercentage?: number;
 }
-export interface IRequestImageToText {
+export interface IRequestImageToText<HasCost extends boolean = false> {
   inputImage?: File | string;
-  includeCost?: boolean;
+  includeCost?: HasCost;
   customTaskUUID?: string;
   retry?: number;
 }
-export interface IImageToText {
+export type IImageToText<HasCost extends boolean = false> = {
   taskType: ETaskType;
   taskUUID: string;
   text: string;
-  cost?: number;
-}
+} & CostField<HasCost>
 
-export interface IRemoveImageBackground extends IRequestImageToText {
-  outputType?: IOutputType;
+export type IRemoveImageBackground<TOutput extends IOutputType = any, HasCost extends boolean = false> = {
+  outputType?: TOutput;
   outputFormat?: IOutputFormat;
   model: string;
   settings?: {
@@ -221,41 +238,36 @@ export interface IRemoveImageBackground extends IRequestImageToText {
     alphaMattingBackgroundThreshold?: number;
     alphaMattingErodeSize?: number;
   };
-  includeCost?: boolean;
+  includeCost?: HasCost;
   outputQuality?: number;
   retry?: number;
-}
+} & IRequestImageToText<HasCost>
 
-export interface IRemoveImage {
+export type IRemoveImage<TOutput extends IOutputType = any, HasCost extends boolean = false> = {
   taskType: ETaskType;
   taskUUID: string;
   imageUUID: string;
   inputImageUUID: string;
-  imageURL?: string;
-  imageBase64Data?: string;
-  imageDataURI?: string;
-  cost?: number;
-}
+} & OutputTypeFieldMap[TOutput] & CostField<HasCost>
 
-export interface IPromptEnhancer {
+export interface IPromptEnhancer<HasCost extends boolean = false> {
   promptMaxLength?: number;
   promptVersions?: number;
   prompt: string;
-  includeCost?: boolean;
+  includeCost?: HasCost;
   customTaskUUID?: string;
   retry?: number;
 }
 
-export interface IEnhancedPrompt extends IImageToText {}
+export type IEnhancedPrompt<HasCost extends boolean = false> = IImageToText<HasCost>
 
-export interface IUpscaleGan {
+export interface IUpscaleGan<TOuput extends IOutputType = any, HasCost extends boolean = false> {
   inputImage: File | string;
   upscaleFactor: number;
-  outputType?: IOutputType;
+  outputType?: TOuput;
   outputFormat?: IOutputFormat;
-  includeCost?: boolean;
+  includeCost?: HasCost;
   outputQuality?: number;
-
   customTaskUUID?: string;
   retry?: number;
 }
@@ -355,7 +367,7 @@ export type RequireOnlyOne<T, Keys extends keyof T = keyof T> = Pick<
 > &
   {
     [K in Keys]-?: Required<Pick<T, K>> &
-      Partial<Record<Exclude<Keys, K>, undefined>>;
+    Partial<Record<Exclude<Keys, K>, undefined>>;
   }[Keys];
 
 export type ListenerType = {