diff --git a/packages/amos-boxes/src/recordMapBox.ts b/packages/amos-boxes/src/recordMapBox.ts
index ddfd35b..e15a28d 100644
--- a/packages/amos-boxes/src/recordMapBox.ts
+++ b/packages/amos-boxes/src/recordMapBox.ts
@@ -23,6 +23,7 @@ export interface RecordMapBox<RM extends RecordMap<any, any> = RecordMap<any, an
     ShapeBox<RM, 'setAll' | 'mergeAll', never, RecordMap<Record<{}>, never>> {
   setItem(key: MapKey<RM>, value: MapValue<RM>): Mutation<RM>;
   setItem(value: MapValue<RM>): Mutation<RM>;
+  /** {@link RecordMap.mergeItem} */
   mergeItem(props: PartialRequiredProps<MapValue<RM>, RecordMapKeyField<RM>>): Mutation<RM>;
   mergeItem(key: MapKey<RM>, props: PartialProps<MapValue<RM>>): Mutation<RM>;
 }
diff --git a/packages/amos-core/src/box.ts b/packages/amos-core/src/box.ts
index 69a978a..def7caf 100644
--- a/packages/amos-core/src/box.ts
+++ b/packages/amos-core/src/box.ts
@@ -87,6 +87,10 @@ export interface BoxFactory<B extends Box = Box> extends BoxFactoryStatic<B> {
   new (key: string, initialState: BoxState<B>): B;
 }
 
+export interface BoxFactoryMutationOptions<B extends Box, A extends any[] = any> {
+  update: (box: B, state: BoxState<B>, ...args: A) => BoxState<B>;
+}
+
 export interface BoxFactorySelectorOptions<S = any, A extends any[] = any, R = any>
   extends Omit<Partial<SelectorOptions<A, R>>, 'type' | 'compute'> {
   derive?: (state: S, ...args: A) => R;
@@ -102,7 +106,10 @@ export interface BoxFactoryOptions<TBox extends Box, TParentBox = {}> {
           ? never
           : P
         : never]: TBox[P] extends MutationFactory<infer A, BoxState<TBox>>
-      ? null | ((state: BoxState<TBox>, ...args: A) => BoxState<TBox>)
+      ?
+          | null
+          | ((state: BoxState<TBox>, ...args: A) => BoxState<TBox>)
+          | BoxFactoryMutationOptions<TBox, A>
       : never;
   };
   selectors: {
@@ -152,12 +159,15 @@ function createBoxFactory<B extends Box, SB = {}>(
         }
       };
   for (const k in mutations) {
-    const fn =
-      typeof mutations[k] === 'function'
-        ? mutations[k]
-        : (state: any, ...args: any[]) => state[k](...args);
     Object.defineProperty(Box.prototype, k, {
-      value: function (this: Box, ...args: any[]): Mutation {
+      value: function (this: B, ...args: any[]): Mutation {
+        const fn: (state: any, ...args: any[]) => any =
+          typeof mutations[k] === 'function'
+            ? mutations[k]
+            : !mutations[k]
+              ? (state: any, ...args: any[]) => state[k](...args)
+              : (state: any, ...args: any[]) =>
+                  (mutations[k] as BoxFactoryMutationOptions<B>).update(this, state, ...args);
         return createAmosObject<Mutation>('mutation', {
           type: `${this.key}/${k as string}`,
           mutator: (state: any) => fn(state, ...args),
@@ -178,7 +188,7 @@ function createBoxFactory<B extends Box, SB = {}>(
           ...resolvedOptions,
           id: this.id,
           type: `${this.key}/${k as string}`,
-          compute: (select: Select, ...args) => derive(select(this), ...args),
+          compute: (select: Select) => derive(select(this), ...args),
           args: args,
         });
       },
@@ -194,7 +204,11 @@ function createBoxFactory<B extends Box, SB = {}>(
 export const Box: BoxFactory = createBoxFactory<Box>({
   name: 'Box',
   mutations: {
-    setState: (state, next) => resolveFuncValue(next, state),
+    setState: {
+      update: (box, state, ...args) => {
+        return args.length ? resolveFuncValue(args[0], state) : box.initialState;
+      },
+    },
   },
   selectors: {},
 });
diff --git a/packages/amos-core/src/selector.spec.ts b/packages/amos-core/src/selector.spec.ts
index ded8be0..4da866c 100644
--- a/packages/amos-core/src/selector.spec.ts
+++ b/packages/amos-core/src/selector.spec.ts
@@ -3,23 +3,31 @@
  * @author acrazing <joking.young@gmail.com>
  */
 
-import { selectUser } from 'amos-testing';
+import { double, fourfold, select, selectUser } from 'amos-testing';
 import { createAmosObject, is } from 'amos-utils';
-import { Selector } from './selector';
+import { Selector, SelectorFactory } from './selector';
 
 describe('selector', () => {
   it('should create selector factory', () => {
-    expect(selectUser).toBe(expect.any(Function));
+    expect(selectUser).toEqual(expect.any(Function));
+    expect({ ...selectUser }).toEqual(
+      createAmosObject<SelectorFactory>('selector_factory', {
+        id: expect.any(String),
+      }),
+    );
   });
   it('should create selector', () => {
-    expect(selectUser()).toEqual(
+    const s = double(3);
+    expect(s).toEqual(
       createAmosObject<Selector>('selector', {
         compute: expect.any(Function),
-        type: '',
+        type: 'amos/double',
         equal: is,
-        args: [],
+        args: [3],
         id: expect.any(String),
       }),
     );
+    expect(s.compute(select)).toEqual(6);
+    expect(fourfold(3).compute(select)).toEqual(12);
   });
 });
diff --git a/packages/amos-core/src/selector.ts b/packages/amos-core/src/selector.ts
index a746a7b..53bd798 100644
--- a/packages/amos-core/src/selector.ts
+++ b/packages/amos-core/src/selector.ts
@@ -18,7 +18,6 @@ export type Compute<A extends any[] = any, R = any> = (select: Select, ...args:
 
 export interface SelectorOptions<A extends any[] = any, R = any> {
   type: string;
-  compute: Compute<A, R>;
 
   /**
    * The equal fn, which is used for check the result is updated or not. If the fn
@@ -50,7 +49,8 @@ export interface SelectorOptions<A extends any[] = any, R = any> {
 export interface Selector<A extends any[] = any, R = any>
   extends AmosObject<'selector'>,
     SelectorOptions<A, R> {
-  args: A;
+  args: readonly unknown[];
+  compute: (select: Select) => R;
 }
 
 export interface SelectorFactory<A extends any[] = any, R = any>
@@ -58,7 +58,7 @@ export interface SelectorFactory<A extends any[] = any, R = any>
   (...args: A): Selector<A, R>;
 }
 
-export const enhanceSelector = enhancerCollector<[SelectorOptions], SelectorFactory>();
+export const enhanceSelector = enhancerCollector<[Compute, SelectorOptions], SelectorFactory>();
 
 export function selector<A extends any[], R>(
   compute: Compute<A, R>,
@@ -67,11 +67,11 @@ export function selector<A extends any[], R>(
   const finalOptions = { ...options } as SelectorOptions;
   finalOptions.type ??= '';
   finalOptions.equal ??= is;
-  finalOptions.compute = compute;
-  return enhanceSelector.apply([finalOptions], (options) => {
+  return enhanceSelector.apply([compute, finalOptions], (compute, options) => {
     const factory = createAmosObject<SelectorFactory>('selector_factory', ((...args: A) => {
       return createAmosObject<Selector<A, R>>('selector', {
         ...options,
+        compute: (select) => compute(select, ...args),
         id: factory.id,
         args,
       });
diff --git a/packages/amos-core/src/signal.spec.ts b/packages/amos-core/src/signal.spec.ts
index d710629..ef36ef9 100644
--- a/packages/amos-core/src/signal.spec.ts
+++ b/packages/amos-core/src/signal.spec.ts
@@ -3,7 +3,7 @@
  * @author acrazing <joking.young@gmail.com>
  */
 
-import { LOGOUT } from 'amos-testing';
+import { LOGOUT, LogoutEvent, select } from 'amos-testing';
 import { isAmosObject } from 'amos-utils';
 import { pick } from 'lodash';
 
@@ -14,13 +14,15 @@ describe('event', () => {
     expect(LOGOUT.dispatch).toBeInstanceOf(Function);
   });
   it('should create signal', () => {
-    const s = LOGOUT({ userId: 1, sessionId: 1 });
+    const e: LogoutEvent = { userId: 1, sessionId: 1 };
+    const s = LOGOUT(e);
     expect(isAmosObject(s, 'signal')).toBe(true);
     expect(pick(s, 'args', 'creator', 'factory', 'type')).toEqual({
-      args: [{ userId: 1, sessionId: 1 }],
+      args: [e],
       creator: expect.any(Function),
       factory: LOGOUT,
       type: 'session.logout',
     });
+    expect(s.creator(select, ...s.args)).toBe(e);
   });
 });
diff --git a/packages/amos-core/src/signal.ts b/packages/amos-core/src/signal.ts
index 8e7dcdb..75fe0e7 100644
--- a/packages/amos-core/src/signal.ts
+++ b/packages/amos-core/src/signal.ts
@@ -9,7 +9,7 @@ import {
   createEventCenter,
   enhancerCollector,
   EventCenter,
-  identity,
+  second,
 } from 'amos-utils';
 import { Dispatch, Select } from './types';
 
@@ -64,7 +64,7 @@ export function signal(a: any, b?: any, c?: any): SignalFactory {
   const bIsFunc = typeof b === 'function';
   const options: SignalOptions = (bIsFunc ? c : b) || {};
   options.type = a;
-  options.creator = (bIsFunc && b) || identity;
+  options.creator = (bIsFunc && b) || second;
   const factory = enhanceSignal.apply([options as SignalOptions], (options) => {
     return Object.assign((...args: any[]) => {
       return createAmosObject<Signal>('signal', {
diff --git a/packages/amos-core/src/store.spec.ts b/packages/amos-core/src/store.spec.ts
index fa28a6a..d01ffc7 100644
--- a/packages/amos-core/src/store.spec.ts
+++ b/packages/amos-core/src/store.spec.ts
@@ -3,7 +3,20 @@
  * @author junbao <junbao@moego.pet>
  */
 
-import { loginAsync, LOGOUT, LogoutEvent, sessionIdBox, sessionMapBox } from 'amos-testing';
+import {
+  addTodo,
+  countBox,
+  LOGIN,
+  loginAsync,
+  loginSync,
+  LOGOUT,
+  LogoutEvent,
+  selectTodoList,
+  sessionIdBox,
+  sessionMapBox,
+  todoMapBox,
+} from 'amos-testing';
+import { pick } from 'lodash';
 import { createStore, Store } from './store';
 
 describe('store', () => {
@@ -37,6 +50,37 @@ describe('store', () => {
     const s4 = store.dispatch(LOGOUT({ userId: 1, sessionId: s3 }));
     expect(s4).toEqual<LogoutEvent>({ userId: 1, sessionId: s3 });
     state[sessionMapBox.key] = sessionMapBox.initialState;
-    expect(store.snapshot()).toEqual(state);
+    expect(pick(store.snapshot(), Object.keys(state))).toMatchObject(state);
+  });
+
+  it('should select base selectable', async () => {
+    const { select, dispatch } = createStore();
+    expect(select(sessionMapBox)).toBe(sessionMapBox.initialState);
+    const id = await dispatch(addTodo({ title: 'Hello', description: 'World' }));
+    expect(pick(select(todoMapBox.getItem(id)).toJSON(), ['id', 'title', 'description'])).toEqual({
+      id: id,
+      title: 'Hello',
+      description: 'World',
+    });
+    expect(select(selectTodoList()).toJSON()).toEqual([id]);
+  });
+
+  it('should dispatch event', () => {
+    const { select, dispatch, subscribe } = createStore();
+    const f1 = jest.fn();
+    const u1 = subscribe(f1);
+    dispatch(loginSync(1));
+    expect(f1).toHaveBeenCalledTimes(1);
+    f1.mockReset();
+    select(countBox);
+    expect(f1).toHaveBeenCalledTimes(0);
+    dispatch(loginSync(1));
+    dispatch(countBox.setState());
+    dispatch(LOGIN({ userId: 1, sessionId: 1 }));
+    expect(f1).toHaveBeenCalledTimes(3);
+    f1.mockReset();
+    u1();
+    dispatch(LOGOUT({ userId: 1, sessionId: 1 }));
+    expect(f1).toHaveBeenCalledTimes(0);
   });
 });
diff --git a/packages/amos-core/src/store.ts b/packages/amos-core/src/store.ts
index 2eaf56a..d240d03 100644
--- a/packages/amos-core/src/store.ts
+++ b/packages/amos-core/src/store.ts
@@ -148,7 +148,7 @@ export function createStore(options: StoreOptions = {}, ...enhancers: StoreEnhan
             }
             return store.state[selectable.key];
           }
-          return selectable.compute(store.select, ...selectable.args);
+          return selectable.compute(store.select);
         },
       };
     },
diff --git a/packages/amos-shapes/src/RecordMap.ts b/packages/amos-shapes/src/RecordMap.ts
index 3daac21..af80f6d 100644
--- a/packages/amos-shapes/src/RecordMap.ts
+++ b/packages/amos-shapes/src/RecordMap.ts
@@ -37,6 +37,7 @@ export class RecordMap<R extends Record<any>, KF extends keyof RecordProps<R>> e
   override mergeItem(a: any, b?: any) {
     const props = b ?? a;
     const key = b ? a : a[this.keyField];
+    props[this.keyField] = key;
     return this.setItem(key, this.getItem(key).merge(props));
   }
 
@@ -69,7 +70,15 @@ export class RecordMap<R extends Record<any>, KF extends keyof RecordProps<R>> e
       | ReadonlyArray<PartialRequiredProps<R, KF> | Entry<IDOf<R[KF]>, PartialProps<R>>>,
   ): this {
     if (Array.isArray(items)) {
-      return super.setAll(items.map((v): any => (Array.isArray(v) ? v : [v[this.keyField], v])));
+      return super.setAll(
+        items.map((v): any => {
+          if (Array.isArray(v)) {
+            v[1][this.keyField] = v[0];
+            return v;
+          }
+          return [v[this.keyField], v];
+        }),
+      );
     } else {
       return super.setAll(
         Object.entries(items).map(([k, v]): any => [k, this.getItem(k as IDOf<R[KF]>).merge(v)]),
diff --git a/packages/amos-testing/src/store/misc.actions.ts b/packages/amos-testing/src/store/misc.actions.ts
index 400583d..32024fb 100644
--- a/packages/amos-testing/src/store/misc.actions.ts
+++ b/packages/amos-testing/src/store/misc.actions.ts
@@ -5,12 +5,15 @@
  * keep atomic boxes
  */
 
-import { action } from 'amos-core';
-import { countBox } from './misc.boxes';
+import { action, selector } from 'amos-core';
 import { sleep } from '../utils';
+import { countBox } from './misc.boxes';
 
 export const addTwiceAsync = action(async (dispatch, select, value: number) => {
   await sleep(1);
   dispatch(countBox.add(value));
   dispatch(countBox.add(value));
 });
+
+export const double = selector((select, v: number) => v * 2);
+export const fourfold = selector((select, v: number) => select(double(v)) * 2);
diff --git a/packages/amos-testing/src/store/session.boxes.ts b/packages/amos-testing/src/store/session.boxes.ts
index d3fbd69..cd6d422 100644
--- a/packages/amos-testing/src/store/session.boxes.ts
+++ b/packages/amos-testing/src/store/session.boxes.ts
@@ -25,6 +25,6 @@ export class SessionRecord extends Record<SessionModel>({
 }
 
 export const sessionMapBox = recordMapBox('sessions', SessionRecord, 'id');
-sessionMapBox.subscribe(LOGOUT, (state, data) => state.removeItem(data.userId));
+sessionMapBox.subscribe(LOGOUT, (state, data) => state.removeItem(data.sessionId));
 
 export const sessionIdBox = box('sessions.currentId', 0);
diff --git a/packages/amos-testing/src/store/todo.actions.ts b/packages/amos-testing/src/store/todo.actions.ts
index 3342f7d..edcf8e6 100644
--- a/packages/amos-testing/src/store/todo.actions.ts
+++ b/packages/amos-testing/src/store/todo.actions.ts
@@ -18,5 +18,6 @@ export const addTodo = action(
     await sleep();
     const id = Math.random();
     dispatch([todoMapBox.mergeItem(id, input), userTodoListBox.unshiftIn(userId, id)]);
+    return id;
   },
 );
diff --git a/packages/amos-utils/src/equals.ts b/packages/amos-utils/src/equals.ts
index 729b3fe..d318e2d 100644
--- a/packages/amos-utils/src/equals.ts
+++ b/packages/amos-utils/src/equals.ts
@@ -19,6 +19,7 @@ export const is: (x: any, y: any) => boolean = Object.is || shimObjectIs;
  * @param v
  */
 export const identity = <T>(v: T) => v;
+export const second = <T>(a: any, b: T) => b;
 export const notNullable = <T>(v: T): v is Exclude<T, undefined | null> => v != null;
 export const isNullable = (v: unknown): v is undefined | null => v == null;
 export const isTruly = <T>(v: T): v is Exclude<T, undefined | null | '' | 0 | false> => !!v;