diff --git a/example/parallelExecution.ts b/example/parallelExecution.ts
index 1010ee8..73dd8c6 100644
--- a/example/parallelExecution.ts
+++ b/example/parallelExecution.ts
@@ -1,18 +1,19 @@
 
-import { Command, Executor, handleCommand } from 'redux-executor';
+import { Action } from 'redux';
+import { Executor, handleCommand } from 'redux-executor';
 
 /**
  * ParallelCommand is a command that will execute all commands from payload in parallel.
  * As a payload of ParallelCommand is a list of commands, you can put there another
  * ParallelCommand or SequenceCommand and build nested tree of execution.
  */
-interface ParallelCommand extends Command {
-  type: 'PARALLEL';
-  payload: Command[];
+interface ParallelCommand extends Action {
+  type: 'PARALLEL()';
+  payload: Action[];
 }
 
 export const parallelCommandExecutor: Executor<any> = handleCommand<any, ParallelCommand>(
-  'PARALLEL',
+  'PARALLEL()',
   (command, dispatch) => Promise.all(
     command.payload.map(command => dispatch(command).promise || Promise.resolve())
   ).then(() => undefined)
diff --git a/example/sequenceExecution.ts b/example/sequenceExecution.ts
index f03a1b7..32a05a6 100644
--- a/example/sequenceExecution.ts
+++ b/example/sequenceExecution.ts
@@ -1,18 +1,19 @@
 
-import { Command, Executor, handleCommand } from 'redux-executor';
+import { Action } from 'redux';
+import { Executor, handleCommand } from 'redux-executor';
 
 /**
  * SequenceCommand is a command that will execute all commands from payload in given order.
  * As a payload of SequenceCommand is a list of commands, you can put there another
  * SequenceCommand or ParallelCommand and build nested tree of execution.
  */
-interface SequenceCommand extends Command {
-  type: 'SEQUENCE';
-  payload: Command[];
+interface SequenceCommand extends Action {
+  type: 'SEQUENCE()';
+  payload: Action[];
 }
 
 export const sequenceCommandExecutor: Executor<any> = handleCommand<any, SequenceCommand>(
-  'SEQUENCE',
+  'SEQUENCE()',
   (command, dispatch) => command.payload.reduce(
     (promise, command) => promise.then(() => dispatch(command).promise || Promise.resolve()),
     Promise.resolve()
diff --git a/package.json b/package.json
index 9e412d6..94f84f9 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "redux-executor",
-  "version": "0.5.1",
+  "version": "0.5.2",
   "description": "Redux enhancer for handling side effects.",
   "main": "lib/index.js",
   "types": "lib/index.d.ts",
diff --git a/src/Command.ts b/src/Command.ts
deleted file mode 100644
index 05054cb..0000000
--- a/src/Command.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-import { Action } from 'redux';
-
-export interface Command extends Action {
-  command: true;
-}
diff --git a/src/ExecutableDispatch.ts b/src/ExecutableDispatch.ts
index 20c2333..0e560d1 100644
--- a/src/ExecutableDispatch.ts
+++ b/src/ExecutableDispatch.ts
@@ -1,5 +1,9 @@
 import { Dispatch, Action } from 'redux';
 
+/**
+ * Dispatch method that adds promise field for commands dispatches results.
+ * It allows executors to synchronize dispatches.
+ */
 export interface ExecutableDispatch<S> extends Dispatch<S> {
   <A extends Action>(action: A): A & { promise?: Promise<void> };
 }
diff --git a/src/ExecutableStore.ts b/src/ExecutableStore.ts
index 0e3229f..912fab9 100644
--- a/src/ExecutableStore.ts
+++ b/src/ExecutableStore.ts
@@ -2,6 +2,9 @@ import { Store } from 'redux';
 import { Executor } from './Executor';
 import { ExecutableDispatch } from './ExecutableDispatch';
 
+/**
+ * Store that can handle commands and executors.
+ */
 export interface ExecutableStore<S> extends Store<S> {
   dispatch: ExecutableDispatch<S>;
   replaceExecutor(nextExecutor: Executor<S>): void;
diff --git a/src/Executor.ts b/src/Executor.ts
index 0ceb5e1..401149c 100644
--- a/src/Executor.ts
+++ b/src/Executor.ts
@@ -1,5 +1,13 @@
-import { Command } from "./Command";
-import { ExecutableDispatch } from "./ExecutableDispatch";
+import { Action } from 'redux';
+import { ExecutableDispatch } from './ExecutableDispatch';
 
-export type Executor<S> = <C extends Command>(command: C, dispatch: ExecutableDispatch<S>, state: S) => Promise<void> | void;
-export type NarrowExecutor<S, C extends Command> = (command: C, dispatch: ExecutableDispatch<S>, state: S) => Promise<void> | void;
+/**
+ * Executor is an simple function that executes some side effects on given command.
+ * They can return promise if side effect is asynchronous.
+ */
+export type Executor<S> = <A extends Action>(command: A, dispatch: ExecutableDispatch<S>, state: S) => Promise<void> | void;
+
+/**
+ * It's executor limited to given action (command) type.
+ */
+export type NarrowExecutor<S, A extends Action> = (command: A, dispatch: ExecutableDispatch<S>, state: S) => Promise<void> | void;
diff --git a/src/combineExecutors.ts b/src/combineExecutors.ts
index 48ac5fa..875d55e 100644
--- a/src/combineExecutors.ts
+++ b/src/combineExecutors.ts
@@ -1,7 +1,13 @@
-import { Command } from './Command';
+import { Action } from 'redux';
 import { Executor } from './Executor';
 import { ExecutableDispatch } from './ExecutableDispatch';
 
+/**
+ * Combine executors to get one that will call wrapped.
+ *
+ * @param executors Executors to combine
+ * @returns Executor that wraps all given executors
+ */
 export function combineExecutors<S>(...executors: Executor<S>[]): Executor<S> {
   // check executors type in runtime
   const invalidExecutorsIndexes: number[] = executors
@@ -16,7 +22,7 @@ export function combineExecutors<S>(...executors: Executor<S>[]): Executor<S> {
     );
   }
 
-  return function combinedExecutor<C extends Command>(command: C, dispatch: ExecutableDispatch<S>, state: S): Promise<void> {
+  return function combinedExecutor<A extends Action>(command: A, dispatch: ExecutableDispatch<S>, state: S): Promise<void> {
     return Promise.all(
       executors
         .map(executor => executor(command, dispatch, state))
diff --git a/src/createExecutableStore.ts b/src/createExecutableStore.ts
index b45a901..8a7d841 100644
--- a/src/createExecutableStore.ts
+++ b/src/createExecutableStore.ts
@@ -3,6 +3,15 @@ import { Executor } from './Executor';
 import { ExecutableStore } from './ExecutableStore';
 import { createExecutorEnhancer } from './createExecutorEnhancer';
 
+/**
+ * Create store that will be able to handle executors and commands.
+ *
+ * @param reducer Main redux reducer
+ * @param executor Main redux executor
+ * @param preloadedState State that should be initialized
+ * @param enhancer Additional enhancer
+ * @returns Executable Store that will handle commands and executors
+ */
 export function createExecutableStore<S>(
   reducer: Reducer<S>,
   executor: Executor<S>,
diff --git a/src/createExecutorEnhancer.ts b/src/createExecutorEnhancer.ts
index fd758e4..b83b689 100644
--- a/src/createExecutorEnhancer.ts
+++ b/src/createExecutorEnhancer.ts
@@ -3,11 +3,17 @@ import { Executor } from './Executor';
 import { ExecutableStore } from './ExecutableStore';
 import { isCommand } from './isCommand';
 
-export const EXECUTOR_INIT: '@@executor/INIT' = '@@executor/INIT';
+export const EXECUTOR_INIT: string = '@@executor/INIT()';
 
 export type StoreExecutableEnhancer<S> = (next: StoreEnhancerStoreCreator<S>) => StoreEnhancerStoreExecutableCreator<S>;
 export type StoreEnhancerStoreExecutableCreator<S> = (reducer: Reducer<S>, preloadedState: S) => ExecutableStore<S>;
 
+/**
+ * Create enhacer for redux store. This enhancer adds commands and executors support.
+ *
+ * @param executor Main redux executor
+ * @returns Store enhancer
+ */
 export function createExecutorEnhancer<S>(executor: Executor<S>): StoreExecutableEnhancer<S> {
   if (typeof executor !== 'function') {
     throw new Error('Expected the executor to be a function.');
@@ -31,7 +37,7 @@ export function createExecutorEnhancer<S>(executor: Executor<S>): StoreExecutabl
           }
 
           currentExecutor = nextExecutor;
-          executableStore.dispatch({ type: EXECUTOR_INIT, command: true });
+          executableStore.dispatch({ type: EXECUTOR_INIT });
         }
       };
 
diff --git a/src/handleCommand.ts b/src/handleCommand.ts
index c82dc5f..214fdad 100644
--- a/src/handleCommand.ts
+++ b/src/handleCommand.ts
@@ -1,12 +1,27 @@
 
+import { Action } from 'redux';
 import { Executor, NarrowExecutor } from './Executor';
-import { Command } from './Command';
 import { ExecutableDispatch } from './ExecutableDispatch';
 
-export function handleCommand<S, C extends Command>(type: C['type'], executor: NarrowExecutor<S, C>): Executor<S> {
-  return function wideExecutor(command: Command, dispatch: ExecutableDispatch<S>, state: S): Promise<void> | void {
+/**
+ * Wraps executor to handle only one type of command.
+ *
+ * @param type Type which our target commands should have.
+ * @param executor Wrapped executor
+ * @returns Executor that runs wrapped executor only for commands with given type.
+ */
+export function handleCommand<S, A extends Action>(type: string, executor: NarrowExecutor<S, A>): Executor<S> {
+  if (!type || type.length < 3 || ')' !== type[type.length - 1] || '(' !== type[type.length - 2]) {
+    throw new Error(`Expected type to be valid command type with '()' ending. Given '${type}' type. Maybe typo?`);
+  }
+
+  if (typeof executor !== 'function') {
+    throw new Error('Expected the executor to be a function.');
+  }
+
+  return function wideExecutor(command: Action, dispatch: ExecutableDispatch<S>, state: S): Promise<void> | void {
     if (command && command.type === type) {
-      return executor(command as C, dispatch, state);
+      return executor(command as A, dispatch, state);
     }
   };
 }
diff --git a/src/index.ts b/src/index.ts
index f089cc8..78dfaec 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,5 +1,4 @@
 // typings
-export { Command } from './Command';
 export { ExecutableDispatch } from './ExecutableDispatch';
 export { ExecutableStore } from './ExecutableStore';
 export { Executor, NarrowExecutor } from './Executor';
diff --git a/src/isCommand.ts b/src/isCommand.ts
index 5d98568..e14add2 100644
--- a/src/isCommand.ts
+++ b/src/isCommand.ts
@@ -1,4 +1,15 @@
 
-export function isCommand(action: any): boolean {
-  return !!(action && action.type && true === action.command);
+/**
+ * Checks if given object is command (action with type that ends with () substring).
+ *
+ * @param object Object to check
+ */
+export function isCommand(object: any): boolean {
+  return !!(
+    object &&
+    object.type &&
+    object.type.length >= 3 &&
+    ')' === object.type[object.type.length - 1] && // last char is )
+    '(' === object.type[object.type.length - 2] // and before it there is ( char
+  );
 }
diff --git a/src/mountExecutor.ts b/src/mountExecutor.ts
index 173f43a..b8f2f3f 100644
--- a/src/mountExecutor.ts
+++ b/src/mountExecutor.ts
@@ -1,9 +1,24 @@
+import { Action } from 'redux';
 import { Executor } from './Executor';
-import { Command } from './Command';
 import { ExecutableDispatch } from './ExecutableDispatch';
 
+/**
+ * Mount executor to operate on some substate.
+ *
+ * @param selector Selector to map state to substate
+ * @param executor Executor that runs on substate
+ * @returns Executor that runs on state
+ */
 export function mountExecutor<S1, S2>(selector: (state: S1) => S2, executor: Executor<S2>): Executor<S1> {
-  return function mountedExecutor<C extends Command>(command: C, dispatch: ExecutableDispatch<S1>, state: S1): Promise<void> | void {
+  if (typeof selector !== 'function') {
+    throw new Error('Expected the selector to be a function.');
+  }
+
+  if (typeof executor !== 'function') {
+    throw new Error('Expected the executor to be a function.');
+  }
+
+  return function mountedExecutor<A extends Action>(command: A, dispatch: ExecutableDispatch<S1>, state: S1): Promise<void> | void {
     return executor(command, dispatch, selector(state));
   };
 }
diff --git a/test/combineExecutors.spec.ts b/test/combineExecutors.spec.ts
index 4e67f4a..36ef210 100644
--- a/test/combineExecutors.spec.ts
+++ b/test/combineExecutors.spec.ts
@@ -26,7 +26,7 @@ describe('combineExecutors', () => {
     const executorAB = combineExecutors(executorA, executorB);
 
     expect(executorAB).to.be.function;
-    let promise = executorAB({ type: 'FOO', command: true }, () => {}, {});
+    let promise = executorAB({ type: 'FOO()' }, () => {}, {});
 
     let thenSpy = chai.spy();
     let catchSpy = chai.spy();
@@ -67,7 +67,7 @@ describe('combineExecutors', () => {
     const executorAB = combineExecutors(executorA, executorB);
 
     expect(executorAB).to.be.function;
-    let promise = executorAB({ type: 'FOO', command: true }, () => {}, {});
+    let promise = executorAB({ type: 'FOO()' }, () => {}, {});
 
     let thenSpy = chai.spy();
     let catchSpy = chai.spy();
diff --git a/test/createExecutorEnhancer.spec.ts b/test/createExecutorEnhancer.spec.ts
index 4ac9c95..ab8dec8 100644
--- a/test/createExecutorEnhancer.spec.ts
+++ b/test/createExecutorEnhancer.spec.ts
@@ -87,7 +87,7 @@ describe('createExecutorEnhancer', () => {
 
     expect(dispatchSpy).to.not.have.been.called;
 
-    const commandResult = executableStore.dispatch({ type: 'DETECTOR_COMMAND', command: true });
+    const commandResult = executableStore.dispatch({ type: 'DETECTOR_COMMAND()' });
     expect(dispatchSpy).to.not.have.been.called;
     expect(commandResult).to.exist;
     expect(commandResult.promise).to.exist;
@@ -95,15 +95,15 @@ describe('createExecutorEnhancer', () => {
 
     executableStore.replaceExecutor(nextExecutorSpy);
     expect(dispatchSpy).to.not.have.been.called;
-    expect(nextExecutorSpy).to.have.been.called.with({ type: EXECUTOR_INIT, command: true }, executableStore.dispatch, {});
+    expect(nextExecutorSpy).to.have.been.called.with({ type: EXECUTOR_INIT }, executableStore.dispatch, {});
 
-    const nextCommandResult = executableStore.dispatch({ type: 'NEXT_DETECTOR_COMMAND', command: true });
+    const nextCommandResult = executableStore.dispatch({ type: 'NEXT_DETECTOR_COMMAND()' });
     expect(dispatchSpy).to.not.have.been.called;
     expect(nextCommandResult).to.exist;
     expect(nextCommandResult.promise).to.exist;
     expect(nextCommandResult.promise.then).to.be.function;
 
-    expect(nextExecutorSpy).to.have.been.called.with({ type: 'NEXT_DETECTOR_COMMAND', command: true }, executableStore.dispatch, {});
+    expect(nextExecutorSpy).to.have.been.called.with({ type: 'NEXT_DETECTOR_COMMAND()' }, executableStore.dispatch, {});
     expect(dispatchSpy).to.not.have.been.called;
 
     executableStore.dispatch({ type: 'NON_COMMAND' });
diff --git a/test/handleCommand.spec.ts b/test/handleCommand.spec.ts
index c1e8722..4228049 100644
--- a/test/handleCommand.spec.ts
+++ b/test/handleCommand.spec.ts
@@ -16,19 +16,31 @@ describe('combineExecutors', () => {
     const dispatchSpy = chai.spy();
     const dumbState = {};
 
-    const targetedExecutor = handleCommand('COMMAND_TYPE', executorSpy);
+    const targetedExecutor = handleCommand('COMMAND_TYPE()', executorSpy);
 
     expect(targetedExecutor).to.be.function;
     expect(executorSpy).to.not.have.been.called;
 
     // expect that executor will bypass this command
-    targetedExecutor({ type: 'ANOTHER_COMMAND_TYPE', command: true }, dispatchSpy, dumbState);
+    targetedExecutor({ type: 'ANOTHER_COMMAND_TYPE()' }, dispatchSpy, dumbState);
+    expect(executorSpy).to.not.have.been.called;
+    expect(dispatchSpy).to.not.have.been.called;
+
+    // expect that executor will bypass similar non command
+    targetedExecutor({ type: 'COMMAND_TYPE' }, dispatchSpy, dumbState);
     expect(executorSpy).to.not.have.been.called;
     expect(dispatchSpy).to.not.have.been.called;
 
     // expect that executor will call wrapped executor
-    targetedExecutor({ type: 'COMMAND_TYPE', command: true }, dispatchSpy, dumbState);
-    expect(executorSpy).to.have.been.called.with({ type: 'COMMAND_TYPE', command: true }, dispatchSpy, dumbState);
+    targetedExecutor({ type: 'COMMAND_TYPE()' }, dispatchSpy, dumbState);
+    expect(executorSpy).to.have.been.called.with({ type: 'COMMAND_TYPE()' }, dispatchSpy, dumbState);
     expect(dispatchSpy).to.have.been.called;
   });
+
+  it('should throw an exception for call with invalid argument', () => {
+    expect(() => { (handleCommand as any)('TEST()', undefined); }).to.throw(Error);
+    expect(() => { (handleCommand as any)('TEST()', 123); }).to.throw(Error);
+    expect(() => { (handleCommand as any)('TEST', () => {}); }).to.throw(Error);
+    expect(() => { (handleCommand as any)('TEST', undefined); }).to.throw(Error);
+  });
 });
diff --git a/test/isCommand.spec.ts b/test/isCommand.spec.ts
index e8bef0f..9d3b85b 100644
--- a/test/isCommand.spec.ts
+++ b/test/isCommand.spec.ts
@@ -17,9 +17,11 @@ describe('combineExecutors', () => {
     expect(isCommand(0)).to.be.false;
     expect(isCommand({})).to.be.false;
     expect(isCommand({ type: 'SOME_TYPE' })).to.be.false;
-    expect(isCommand({ type: 'SOME_TYPE', payload: { command: true } })).to.be.false;
-    expect(isCommand({ type: 'SOME_TYPE', meta: { command: true } })).to.be.false;
+    expect(isCommand({ type: 'SOME_TYPE( )' })).to.be.false;
+    expect(isCommand({ type: 'SOME_TYPE)' })).to.be.false;
+    expect(isCommand({ type: 'SOME_TYPE(' })).to.be.false;
+    expect(isCommand({ type: 'SOME_TYP(E)' })).to.be.false;
 
-    expect(isCommand({ type: 'SOME_TYPE', command: true })).to.be.true;
+    expect(isCommand({ type: 'SOME_TYPE()' })).to.be.true;
   });
 });
diff --git a/test/mountExecutor.spec.ts b/test/mountExecutor.spec.ts
index b49ede1..8d10503 100644
--- a/test/mountExecutor.spec.ts
+++ b/test/mountExecutor.spec.ts
@@ -23,7 +23,7 @@ describe('mountExecutor', () => {
     function dumbDispatch(action) {
     }
     function executor(command, dispatch, state) {
-      if (state && state.value === 1 && command && command.type === 'COMMAND_THROUGH_MOUNT') {
+      if (state && state.value === 1 && command && command.type === 'COMMAND_THROUGH_MOUNT()') {
         dispatch({type: 'SELECTORS_WORKED'});
       }
     }
@@ -37,11 +37,18 @@ describe('mountExecutor', () => {
     expect(mountedExecutor).to.be.function;
 
     mountedExecutor(
-      { type: 'COMMAND_THROUGH_MOUNT', command: true },
+      { type: 'COMMAND_THROUGH_MOUNT()' },
       dumbDispatchSpy,
       state
     );
 
     expect(dumbDispatchSpy).to.have.been.called.once.with({type: 'SELECTORS_WORKED'});
   });
+
+  it('should throw an exception for call with invalid argument', () => {
+    expect(() => { (mountExecutor as any)(() => {}, undefined); }).to.throw(Error);
+    expect(() => { (mountExecutor as any)(undefined, () => {}); }).to.throw(Error);
+    expect(() => { (mountExecutor as any)({}, () => {}); }).to.throw(Error);
+    expect(() => { (mountExecutor as any)('test', 'test'); }).to.throw(Error);
+  });
 });
diff --git a/webpack.config.js b/webpack.config.js
index e9f44da..10c2600 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -47,7 +47,12 @@ var config = {
   },
 
   externals: {
-    'redux': 'Redux'
+    'redux': {
+      root: 'Redux',
+      commonjs2: 'redux',
+      commonjs: 'redux',
+      amd: 'redux'
+    }
   }
 };