diff --git a/Basis/Api.py b/Basis/Api.py
index 66040b3..8761b17 100644
--- a/Basis/Api.py
+++ b/Basis/Api.py
@@ -3,6 +3,7 @@
 
 import json
 from gevent import pywsgi
+from Basis.Manage import Manage
 from Basis.Logger import logging
 from Basis.Constant import Version
 from flask import Flask, Response, request
@@ -37,35 +38,80 @@ def tokenCheck() -> bool:
 def getTaskList() -> Response:
     if not tokenCheck():  # token check
         return tokenError()
-    logging.critical('get task list')
-    return jsonResponse({})
+    try:
+        taskList = Manage.listTask()
+        logging.debug('api get task list -> %s' % taskList)
+        return jsonResponse({
+            'success': True,
+            'task': taskList,
+        })
+    except:
+        return jsonResponse({
+            'success': False,
+            'message': 'Unknown error'
+        })
 
 
 @webApi.route('/task', methods = ['POST'])
 def createTask() -> Response:
     if not tokenCheck():  # token check
         return tokenError()
-    logging.critical('create task')
-    return jsonResponse({})
+    checkList = request.json.get('check')
+    proxyList = request.json.get('proxy')
+    if checkList is None or type(checkList) != list:
+        return jsonResponse({
+            'success': False,
+            'message': 'invalid check list',
+        })
+    if proxyList is None or type(proxyList) != list:
+        return jsonResponse({
+            'success': False,
+            'message': 'invalid proxy list',
+        })
+    logging.debug('api create task -> check: %s | proxy: %s' % (checkList, proxyList))
+
+    # TODO: format check and proxy list
+
+    tasks = []
+    for proxy in proxyList:
+        tasks.append({**proxy, 'check': checkList})
+    checkId = Manage.addTask(tasks)
+    logging.debug('api return check id %s' % checkId)
+
+    return jsonResponse({
+        'success': True,
+        'id': checkId,
+        'check': checkList,
+        'proxy': proxyList,
+    })
 
 
 @webApi.route('/task/<taskId>', methods = ['GET'])
-def getTaskInfo() -> Response:
+def getTaskInfo(taskId: str) -> Response:
     if not tokenCheck():  # token check
         return tokenError()
-    logging.critical('get task info')
-    return jsonResponse({})
+    logging.critical('API get task %s info' % taskId)
+    if not Manage.isTask(taskId):
+        return jsonResponse({
+            'success': False,
+            'message': 'task id not found',
+        })
+    return jsonResponse({
+        'success': True,
+        **Manage.getTask(taskId)
+    })
 
 
 @webApi.route('/version', methods = ['GET'])
 def getVersion() -> Response:
     logging.debug('get version -> %s' + Version)
     return jsonResponse({
-        'version': Version
+        'success': True,
+        'version': Version,
     })
 
 
-def startServer(apiPort: int = 7839, apiToken: str = '') -> None:
+def startServer(apiToken: str = '', apiPort: int = 7839) -> None:
     global token
     token = apiToken
     logging.warning('API server at http://:%i/' % apiPort)
diff --git a/Basis/Check.py b/Basis/Check.py
new file mode 100644
index 0000000..4fc3ec2
--- /dev/null
+++ b/Basis/Check.py
@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import time
+from Basis.Logger import logging
+from Builder import Builder, clientEntry
+
+from ProxyChecker import httpCheck  # TODO: refactor in the future
+
+
+def Check(proxyType: str, proxyInfo: dict, checkInfo: dict) -> dict:
+    # TODO: checkInfo -> [...] (only check http for now)
+    if proxyType not in clientEntry:
+        logging.error('Unknown proxy type %s' % proxyType)
+        raise RuntimeError('Unknown proxy type')
+    try:
+        client = Builder(proxyType, proxyInfo)
+    except Exception as reason:
+        logging.error('Client build error -> %s' % reason)
+        raise RuntimeError('Client build error')
+
+    # TODO: debug combine output
+    logging.debug(client.id)
+    logging.debug(client.proxyType)
+    logging.debug(client.proxyInfo)
+    logging.debug(client.socksAddr)
+    logging.debug(client.socksPort)
+
+    # TODO: wait port occupied
+    time.sleep(1)
+    if not client.status():  # client unexpected exit
+        client.destroy()  # remove file and kill sub process
+        logging.error('Client unexpected exit\n%s', client.output)
+        raise RuntimeError('Client unexpected exit')
+
+    # TODO: check process
+    status, _ = httpCheck(client.socksPort)  # TODO: add socks5 addr
+
+    logging.critical('http check status -> %s' % status)
+
+    client.destroy()  # clean up the client
+
+    return {
+        'http': {
+            'status': status,
+            # TODO: more http check info
+        },
+        # TODO: more check items (from checkInfo list)
+    }
+
diff --git a/Basis/Manage.py b/Basis/Manage.py
index 7f5ee2b..ea59be4 100644
--- a/Basis/Manage.py
+++ b/Basis/Manage.py
@@ -50,9 +50,8 @@ class Task(object):
         if completed < len(subList):  # some sub tasks are not completed
             logging.debug('[%s] task still running' % taskId)
             return {
-                'done': False,
-                'total': len(subList),
-                'finish': completed,
+                'finish': False,
+                'percent': '%i%%' % (completed / len(subList))
             }
         logging.debug('[%s] task work complete' % taskId)  # all sub tasks completed
         result = []
@@ -62,7 +61,7 @@ class Task(object):
             result.append(subTask['data'])
         logging.debug('release sub tasks -> %s' % result)
         return {
-            'done': True,
+            'finish': True,
             'result': result
         }
 
diff --git a/demo.py b/demo.py
index 8696076..a3dae6c 100755
--- a/demo.py
+++ b/demo.py
@@ -132,17 +132,20 @@ proxyHysteria = {
 # client = Builder('trojan', proxyTrojan)
 # client = Builder('trojan-go', proxyTrojanGo)
 # client = Builder('brook', proxyBrook)
-client = Builder('hysteria', proxyHysteria)
+# client = Builder('hysteria', proxyHysteria)
+#
+# logging.critical(client.id)
+# logging.critical(client.proxyType)
+# logging.critical(client.proxyInfo)
+# logging.critical(client.socksAddr)
+# logging.critical(client.socksPort)
+#
+# time.sleep(15)
+# logging.critical(client.status())
+#
+# client.destroy()
+# logging.critical(client.status())
+# logging.critical('Client output:\n' + str(client.output))
 
-logging.critical(client.id)
-logging.critical(client.proxyType)
-logging.critical(client.proxyInfo)
-logging.critical(client.socksAddr)
-logging.critical(client.socksPort)
-
-time.sleep(15)
-logging.critical(client.status())
-
-client.destroy()
-logging.critical(client.status())
-logging.critical('Client output:\n' + str(client.output))
+from Basis.Check import Check
+Check('ss', proxySS, {})
diff --git a/main.py b/main.py
index ae87141..76d78e2 100755
--- a/main.py
+++ b/main.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
-
+import os
 import time
 import _thread
 import subprocess
@@ -9,21 +9,28 @@ from Basis.Api import startServer
 from Basis.Constant import Version
 from Basis.Compile import startCompile
 
+dnsServers = None
+# dnsServers = ['223.5.5.5', '119.28.28.28']
+
 
 def startDnsproxy(command: list) -> subprocess.Popen:
     logging.debug('start dnsproxy -> %s' % command)
     return subprocess.Popen(command, stdout = subprocess.PIPE, stderr = subprocess.STDOUT)
 
 
-def daemonDnsproxy(dnsServers: list, localPort: int = 53, cacheSize: int = 4194304) -> None:  # default cache -> 4MiB
-    logging.info('start dnsproxy at port %i -> %s' % (localPort, dnsServers))
+def daemonDnsproxy(servers: list or None, port: int = 53, cache: int = 4194304) -> None:  # default cache size -> 4MiB
+    if servers is None or len(servers) == 0:
+        logging.info('skip dnsproxy process')
+        return
+    logging.info('start dnsproxy at port %i -> %s' % (port, servers))
+    os.system('echo "nameserver 127.0.0.1" > /etc/resolv.conf')  # system dns settings
     dnsCommand = [
         'dnsproxy', '--all-servers',
-        '--port', str(localPort),
-        '--cache', '--cache-size', str(cacheSize)
+        '--port', str(port),
+        '--cache', '--cache-size', str(cache)
     ]
-    for dnsServer in dnsServers:
-        dnsCommand += ['--upstream', dnsServer]
+    for server in servers:
+        dnsCommand += ['--upstream', server]
     dnsproxy = startDnsproxy(dnsCommand)
     while True:
         time.sleep(2)  # daemon time gap
@@ -33,10 +40,24 @@ def daemonDnsproxy(dnsServers: list, localPort: int = 53, cacheSize: int = 41943
             dnsproxy = startDnsproxy(dnsCommand)
 
 
-logging.warning('ProxyC starts running (%s)' % Version)
+from Basis.Check import Check
+from Basis.Manage import Manage
 
-_thread.start_new_thread(startCompile, ('/usr', ))
+def loopCheck() -> None:
+    while True:
+        time.sleep(2)  # TODO: thread pool working
+        subTaskId, subTask = Manage.popSubTask()
+        if subTaskId is None: continue
+        logging.info('new sub task -> %s', subTask)
+        ret = Check(subTask['type'], subTask['info'], {})
+        logging.info('check result -> %s' % ret)
+        subTask.pop('check')
+        subTask['result'] = ret
+        Manage.updateSubTask(subTaskId, subTask)
 
-_thread.start_new_thread(daemonDnsproxy, (['223.5.5.5', '119.28.28.28'], 53))
 
-startServer(apiToken = 'dnomd343')
+logging.warning('ProxyC starts running (%s)' % Version)
+_thread.start_new_thread(startCompile, ('/usr', ))  # python compile (generate .pyc file)
+_thread.start_new_thread(daemonDnsproxy, (dnsServers, 53))  # set system's dns server
+_thread.start_new_thread(loopCheck, ())  # start loop check
+startServer(apiToken = '')  # start api server