服务端 API/应用信息/事件/首次启用应用
# 首次启用应用
**注意事项**：了解事件订阅的使用场景和配置流程，请点击查看 [事件订阅概述](https://open.larksuite.com/document/ukTMukTMukTM/uUTNz4SN1MjL1UzM)
当租户第一次安装并启用此应用时触发此事件，启用应用包含以下场景：
- 当租户管理员后台首次开通应用
- 租户内的普通成员首次安装此应用
只有应用商店应用才能订阅此事件。自建应用无此事件。

**回调示例：**
```json
{ 
    "ts": "1502199207.7171419", //  事件发送的时间，一般近似于事件发生的时间。 
    "uuid": "bc447199585340d1f3728d26b1c0297a",  // 事件的唯一标识
    "token": "41a9425ea7df4536a7623e38fa321bae", // 即Verification Token 
    "type": "event_callback", // 此事件此处始终为event_callback
    "event": { 
        "app_id": "cli_xxx",  // 开通的应用ID
        "tenant_key":"xxx",   // 开通应用的企业唯一标识
        "type":"app_open",     // 事件类型
        "applicants": [ // 应用的申请者，可能有多个
            {
                "open_id":"xxx" ,  // 用户对此应用的唯一标识，同一用户对不同应用的open_id不同
            }
        ],
        "installer": {	// 当应用被管理员安装时，返回此字段。如果是自动安装或由普通成员获取时，没有此字段
             "open_id":"xxx" ,  // 用户对此应用的唯一标识，同一用户对不同应用的open_id不同
        },
        "installer_employee": {  // 当应用被普通成员安装时，返回此字段
             "open_id":"xxx" ,  // 用户对此应用的唯一标识，同一用户对不同应用的open_id不同
		}
    } 
}
```

### 事件订阅示例代码

事件订阅流程可参考：[事件订阅概述](https://open.larksuite.com/document/ukTMukTMukTM/uUTNz4SN1MjL1UzM)，新手入门可参考：[教程](https://open.larksuite.com/document/uAjLw4CM/uMzNwEjLzcDMx4yM3ATM/develop-an-echo-bot/introduction)

**

package main

import (
	"context"
	"fmt"

larkcore "github.com/larksuite/oapi-sdk-go/v3/core"
	larkevent "github.com/larksuite/oapi-sdk-go/v3/event"
	"github.com/larksuite/oapi-sdk-go/v3/event/dispatcher"
	"github.com/larksuite/oapi-sdk-go/v3/service/application/old"
	larkws "github.com/larksuite/oapi-sdk-go/v3/ws"
)

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/golang-sdk-guide/preparations
func main() {
	// 注册事件 Register event
	eventHandler := dispatcher.NewEventDispatcher("", "").
		OnCustomizedEvent("app_open", func(ctx context.Context, event *larkevent.EventReq) error {
			fmt.Printf("[ OnCustomizedEvent access ], type: message, data: %s\n", string(event.Body))
			return nil
		})

// 构建 client Build client
	cli := larkws.NewClient("YOUR_APP_ID", "YOUR_APP_SECRET",
		larkws.WithEventHandler(eventHandler),
		larkws.WithLogLevel(larkcore.LogLevelDebug),
	)

// 建立长连接 Establish persistent connection
	err := cli.Start(context.Background())

if err != nil {
		panic(err)
	}
}

# SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/python--sdk/preparations-before-development
import lark_oapi as lark

def do_customized_event(data: lark.CustomizedEvent) -> None:
    print(f'[ do_customized_event access ], type: message, data: {lark.JSON.marshal(data, indent=4)}')

# 注册事件 Register event
event_handler = lark.EventDispatcherHandler.builder("", "") \
    .register_p1_customized_event("app_open", do_customized_event) \
    .build()

def main():
    # 构建 client Build client
    cli = lark.ws.Client("APP_ID", "APP_SECRET",
                        event_handler=event_handler, log_level=lark.LogLevel.DEBUG)
    # 建立长连接 Establish persistent connection
    cli.start()

if __name__ == "__main__":
    main()

package com.example.sample;

import java.nio.charset.StandardCharsets;
import com.lark.oapi.core.request.EventReq;
import com.lark.oapi.event.CustomEventHandler;
import com.lark.oapi.event.EventDispatcher;
import com.lark.oapi.ws.Client;

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/java-sdk-guide/preparations
public class Sample {
    // 注册事件 Register event
    private static final EventDispatcher EVENT_HANDLER = EventDispatcher.newBuilder("", "")
            .onCustomizedEvent("app_open", new CustomEventHandler() {
                @Override
                public void handle(EventReq event) throws Exception {
                    System.out.printf("[ onCustomizedEvent access ], type: message, data: %s\n", new String(event.getBody(), StandardCharsets.UTF_8));
                }
            })
            .build();

public static void main(String[] args) {
        // 构建 client Build client
        Client client = new Client.Builder("APP_ID", "APP_SECRET")
                .eventHandler(EVENT_HANDLER)
                .build();
        // 建立长连接 Establish persistent connection
        client.start();
    }
}

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/nodejs-sdk/preparation-before-development
import * as Lark from '@larksuiteoapi/node-sdk';
const baseConfig = {
    appId: 'APP_ID',
    appSecret: 'APP_SECRET'
}
// 构建 client Build client
const wsClient = new Lark.WSClient(baseConfig);
// 建立长连接 Establish persistent connection
wsClient.start({
    // 注册事件 Register event
    eventDispatcher: new Lark.EventDispatcher({}).register({
        'app_open': async (data) => {
            console.log(data);
        }
    })
});

package main

import (
	"context"
	"fmt"
	"net/http"

larkcore "github.com/larksuite/oapi-sdk-go/v3/core"
	"github.com/larksuite/oapi-sdk-go/v3/core/httpserverext"
	larkevent "github.com/larksuite/oapi-sdk-go/v3/event"
	"github.com/larksuite/oapi-sdk-go/v3/event/dispatcher"
	"github.com/larksuite/oapi-sdk-go/v3/service/application/old"
)

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/golang-sdk-guide/preparations
func main() {
	// 注册事件 Register event
	eventHandler := dispatcher.NewEventDispatcher("", "").
		OnCustomizedEvent("app_open", func(ctx context.Context, event *larkevent.EventReq) error {
			fmt.Printf("[ OnCustomizedEvent access ], type: message, data: %s\n", string(event.Body))
			return nil
		})

// 创建路由处理器 Create route handler
	http.HandleFunc("/webhook/event", httpserverext.NewEventHandlerFunc(handler, larkevent.WithLogLevel(larkcore.LogLevelDebug)))

err := http.ListenAndServe(":7777", nil)

if err != nil {
		panic(err)
	}
}

# SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/python--sdk/preparations-before-development
from flask import Flask
from lark_oapi.adapter.flask import *
import lark_oapi as lark

app = Flask(__name__)

def do_customized_event(data: lark.CustomizedEvent) -> None:
    print(f'[ do_customized_event access ], type: message, data: {lark.JSON.marshal(data, indent=4)}')

# 注册事件 Register event
event_handler = lark.EventDispatcherHandler.builder("", "") \
    .register_p1_customized_event("app_open", do_customized_event) \
    .build()

# 创建路由处理器 Create route handler
@app.route("/webhook/event", methods=["POST"])
def event():
    resp = event_handler.do(parse_req())
    return parse_resp(resp)

if __name__ == "__main__":
    app.run(port=7777)

package com.lark.oapi.sample.event;

import java.nio.charset.StandardCharsets;
import com.lark.oapi.core.request.EventReq;
import com.lark.oapi.event.CustomEventHandler;
import com.lark.oapi.sdk.servlet.ext.ServletAdapter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/java-sdk-guide/preparations
@RestController
public class EventController {

// 注册事件 Register event
    private static final EventDispatcher EVENT_HANDLER = EventDispatcher.newBuilder("verificationToken", "encryptKey")
            .onCustomizedEvent("app_open", new CustomEventHandler() {
                @Override
                public void handle(EventReq event) throws Exception {
                    System.out.printf("[ onCustomizedEvent access ], type: message, data: %s\n", new String(event.getBody(), StandardCharsets.UTF_8));
                }
            })
            .build();

// 注入 ServletAdapter 实例 Inject ServletAdapter instance
    @Autowired
    private ServletAdapter servletAdapter;

// 创建路由处理器 Create route handler
    @RequestMapping("/webhook/event")
    public void event(HttpServletRequest request, HttpServletResponse response)
            throws Throwable {
        // 回调扩展包提供的事件回调处理器 Callback handler provided by the extension package
        servletAdapter.handleEvent(request, response, EVENT_DISPATCHER);
    }
}

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/nodejs-sdk/preparation-before-development
import http from 'http';
import * as lark from '@larksuiteoapi/node-sdk';

// 注册事件 Register event
const eventDispatcher = new lark.EventDispatcher({
    encryptKey: '',
    verificationToken: '',
}).register({
    'app_open': async (data) => {
        console.log(data);
        return 'success';
    },
});

const server = http.createServer();
// 创建路由处理器 Create route handler
server.on('request', lark.adaptDefault('/webhook/event', eventDispatcher));
server.listen(3000);