diff --git a/doc/acid/apiutil.md b/doc/acid/apiutil.md
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+<!-- START doctoc generated TOC please keep comment here to allow auto update -->
+<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
+#   Table of Content
+
+- [Name](#name)
+- [Status](#status)
+- [Description](#description)
+- [Synopsis](#synopsis)
+- [Methods](#methods)
+  - [apiutil.output](#apiutiloutput)
+- [Author](#author)
+- [Copyright and License](#copyright-and-license)
+
+<!-- END doctoc generated TOC please keep comment here to allow auto update -->
+
+#   Name
+
+acid.apiutil
+
+#   Status
+
+This library is considered production ready.
+
+#   Description
+
+It provides common ngx output functions.
+
+#   Synopsis
+
+```lua
+local apiutil = require("acid.apiutil")
+
+code = 200
+headers = {['Content-Type']='application/json'}
+body = 'hello'
+
+apiutil.output(code,headers,body)
+```
+
+#   Methods
+
+
+##  apiutil.output
+
+**syntax**:
+`apiutil.output(code, headers, body)`
+
+**arguments**:
+
+-   `code`:
+    is a integer.
+
+-   `headers`:
+    is a table.
+
+    like `{["X-My-Header"] = 'blah blah', ['Set-Cookie'] = {'a=32; path=/', 'b=4; path=/'}}`.
+
+-   `body`:
+    can be str or nil or boolean or nested array table.
+
+    See also [ngx.print](https://github.com/openresty/lua-nginx-module#ngxprint)
+
+**return**:
+Nothing
+
+#   Author
+
+Liu Tongwei(刘桐伟) <tongwei.liu@baishancloud.com>
+
+#   Copyright and License
+
+The MIT License (MIT)
+
+Copyright (c) 2017 Liu Tongwei(刘桐伟) <tongwei.liu@baishancloud.com>
diff --git a/lib/acid/apiutil.lua b/lib/acid/apiutil.lua
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+++ b/lib/acid/apiutil.lua
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+local _M = {}
+
+local ngx = ngx
+
+function _M.output(code, headers, body)
+
+    ngx.status = code
+
+    for k, v in pairs(headers) do
+        ngx.header[k] = v
+    end
+
+    ngx.print(body)
+    ngx.eof()
+
+    ngx.exit(ngx.HTTP_OK)
+end
+
+return _M
diff --git a/t/apiutil.t b/t/apiutil.t
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+# vim:set ft=lua ts=4 sw=4 et ft=perl:
+
+################################################################################
+# DO NOT EDIT THIS FILE.                                                       #
+# Use ./t/build_ngx_ut.sh to regenerate this wrapper file.                     #
+################################################################################
+
+use Test::Nginx::Socket "no_plan";
+
+no_long_string();
+
+# Env TEST_VERBOSE is set by command "prove"
+#
+# Only env var starting with TEST_NGINX_ will be evaluated in the "--- config"
+# block.
+$ENV{TEST_NGINX_ACID_UT_VERBOSE} = $ENV{TEST_VERBOSE} || 0;
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: apiutil
+--- http_config
+    lua_shared_dict        shared_dict_lock 1m;
+    lua_shared_dict        test_shared      10m;
+    lua_check_client_abort on;
+
+    lua_package_path "./lib/?.lua;;";
+    lua_package_cpath "./lib/?.so;;";
+--- config
+    location /t {
+        content_by_lua_block {
+             local apiutil = require("acid.apiutil")
+             local strutil = require("acid.strutil")
+             local args = ngx.req.get_uri_args()
+             code = args['code']
+             body = args['body']
+             headers_split = strutil.split(args['headers'],",")
+             headers = {}
+             for i, v in ipairs(headers_split) do
+                key, value = unpack(strutil.split(v,"="))
+                headers[key] = value
+             end
+             ngx.log(ngx.ERROR,apiutil.output(code,headers,body))
+        }
+    }
+--- pipelined_requests eval
+['GET /t?code=200&headers=Content-Type=application/json,Content-Encoding=gzip,a=b&body=123456',
+'GET /t?code=500&headers=Content-Type=application/xml&body=12345aaa6',
+'GET /t?code=404&headers=Content-Type=application/xml&body=123456']
+--- response_body eval
+['123456',
+'12345aaa6',
+'123456']
+--- error_code eval
+[200,
+500,
+404]
+--- response_headers eval
+['Content-Type: application/json
+Content-Encoding: gzip
+a=b',
+'Content-Type: application/xml',
+'Content-Type: application/xml']