diff --git a/src/base.ts b/src/base.ts
index f99e13f..d6139fb 100644
--- a/src/base.ts
+++ b/src/base.ts
@@ -1,8 +1,5 @@
 import type { ExecutionContainer } from '@artus/injection';
-import {
-  BaseContext, BaseInput, BaseOutput,
-  ContextStorage, ParamsDictionary, Next
-} from './types';
+import { BaseContext, BaseInput, BaseOutput, ContextStorage, ParamsDictionary, Next } from './types';
 
 const ContextStorageSymbol = Symbol('ARTUS::ContextStorage');
 
@@ -14,7 +11,7 @@ export class Output implements BaseOutput {
   public data: ParamsDictionary = new Map();
 }
 
-export class Storage implements ContextStorage<any>{
+export class Storage implements ContextStorage<any> {
   private storageMap = new Map();
 
   get(key?: string | symbol): any {
@@ -29,8 +26,8 @@ export class Storage implements ContextStorage<any>{
 }
 
 export class Context implements BaseContext {
-  public input: BaseInput = new Input();
-  public output: BaseOutput = new Output();
+  public input: Input = new Input();
+  public output: Output = new Output();
 
   private _container!: ExecutionContainer;
   private storageMap = new Map<string, ContextStorage<any>>();
@@ -66,7 +63,7 @@ export class Context implements BaseContext {
   }
 }
 
-export type Middleware = (context: Context, next: Next) => void;
+export type Middleware<T extends BaseContext = any> = (context: T, next: Next) => void;
 export type Middlewares = Middleware[];
 export type PipelineLike = { middlewares: Middlewares };
 export type MiddlewareInput = Middleware | Middlewares | PipelineLike;
diff --git a/src/pipeline.ts b/src/pipeline.ts
index 4061b07..a6b95ad 100644
--- a/src/pipeline.ts
+++ b/src/pipeline.ts
@@ -1,5 +1,5 @@
-
-import { Context, Middlewares, MiddlewareInput, PipelineLike } from "./base";
+import { Middlewares, MiddlewareInput, PipelineLike } from './base';
+import { BaseContext } from './types';
 
 export class Pipeline implements PipelineLike {
   middlewares: Middlewares = [];
@@ -26,7 +26,7 @@ export class Pipeline implements PipelineLike {
     throw new Error(`${middleware} isn't type MiddlewareInput`);
   }
 
-  dispatch(i: number, ctx: Context, execution = { index: -1 }): Promise<any> {
+  dispatch(i: number, ctx: BaseContext, execution = { index: -1 }): Promise<any> {
     if (i <= execution.index) return Promise.reject(new Error('next() called multiple times'));
     execution.index = i;
     let fn = this.middlewares[i];
@@ -38,7 +38,7 @@ export class Pipeline implements PipelineLike {
     }
   }
 
-  run(ctx: Context): Promise<any> {
+  run(ctx: BaseContext): Promise<any> {
     return this.dispatch(0, ctx);
   }
 }
diff --git a/src/types.ts b/src/types.ts
index f6e4fa9..ba6c91d 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -3,22 +3,22 @@ export interface ParamsDictionary {
 }
 
 export interface BaseInput<P = ParamsDictionary> {
-  params: P
-};
+  params?: P;
+}
 
 export interface BaseOutput<P = ParamsDictionary> {
-  data: P
-};
+  data?: P;
+}
 
 export interface BaseContext extends ParamsDictionary {
-  input: BaseInput,
-  output: BaseOutput,
-  namespace: (namespace: string) => ContextStorage<any>,
-  restore?: () => void,
-};
+  input: BaseInput;
+  output: BaseOutput;
+  namespace?: (namespace: string) => ContextStorage<any>;
+  restore?: () => void;
+}
 
 export type ContextStorage<T> = {
-  set: (value: T, key?: string | symbol) => void,
-  get: (key?: string | symbol) => T
+  set: (value: T, key?: string | symbol) => void;
+  get: (key?: string | symbol) => T;
 };
 export type Next = () => Promise<any>;
diff --git a/test/context_pool.test.ts b/test/context_pool.test.ts
index 05c4a1a..cc9efef 100644
--- a/test/context_pool.test.ts
+++ b/test/context_pool.test.ts
@@ -1,26 +1,26 @@
 import { ContextPool } from '../src/context_pool';
 
-describe("test/context_pool.test.ts", () => {
-    it('should get ok', () => {
-        const ctxPool = new ContextPool(1);
-        const container = new Map();
-        const ctx = ctxPool.get(container as any);
-        expect(ctx.container).toBe(container);
-        expect(ctx.input.params).toBeInstanceOf(Map);
-        expect(ctx.output.data).toBeInstanceOf(Map);
-    });
+describe('test/context_pool.test.ts', () => {
+  it('should get ok', () => {
+    const ctxPool = new ContextPool(1);
+    const container = new Map();
+    const ctx = ctxPool.get(container as any);
+    expect(ctx.container).toBe(container);
+    expect(ctx.input.params).toBeInstanceOf(Map);
+    expect(ctx.output.data).toBeInstanceOf(Map);
+  });
 
-    it('should release ok', () => {
-        const ctxPool = new ContextPool(1);
-        const container = new Map();
-        const ctx = ctxPool.get(container as any);
-        ctx.input.params.set('id', 12);
-        ctx.output.data.set('user', { id: 12 });
-        ctxPool.release(ctx);
-        const container2 = new Map();
-        const ctx2 = ctxPool.get(container2 as any);
-        expect(ctx2.container).toBe(container2);
-        expect(ctx.input.params.has('id')).toBe(false);
-        expect(ctx.output.data.has('user')).toBe(false);
-    });
-});
\ No newline at end of file
+  it('should release ok', () => {
+    const ctxPool = new ContextPool(1);
+    const container = new Map();
+    const ctx = ctxPool.get(container as any);
+    ctx.input.params!.set('id', 12);
+    ctx.output.data!.set('user', { id: 12 });
+    ctxPool.release(ctx);
+    const container2 = new Map();
+    const ctx2 = ctxPool.get(container2 as any);
+    expect(ctx2.container).toBe(container2);
+    expect(ctx.input.params!.has('id')).toBe(false);
+    expect(ctx.output.data!.has('user')).toBe(false);
+  });
+});