Receive notifications about channel events

A webhook is a user-defined callback over HTTP. You use webhooks to notify your app or back-end system when certain Voice Calling events occur. Agora Notifications enables you to subscribe to events and receive notifications about them across multiple product lines.

Using Agora Console you subscribe to specific events for your project and configure the URL of the webhooks to receive these events. Agora sends notifications of your events to your webhook every time they occur. Your server authenticates the notification and returns 200 Ok to confirm reception. You use the information in the JSON payload of each notification to give the best user experience to your users.

The following figure illustrates the workflow when Notifications is enabled for the specific Voice Calling events you subscribe to:

1. A user commits an action that creates an event.
2. Notifications sends an HTTPS POST request to your webhook.
3. Your server validates the request signature, then sends a response to Notifications within 10 seconds. The response body must be in JSON.

If Notifications receives 200 OK within 10 seconds of sending the initial notification, the callback is considered successful. If these conditions are not met, Notifications immediately resends the notification. The interval between notification attempts gradually increases. Notifications stops sending notifications after three retries.

To set up and use Notifications, you must have:

• A valid Agora account.

• An active Agora project.

• A computer with Internet access.

  If your network access is restricted by a firewall, call the IP address query API to retrieve the Notifications IP addresses , then configure the firewall to allow these IP addresses.

In order to handle notifications for the events you subscribe to, you need to:

• Create your webhook
• Enable Notifications
• Verify Notifications signatures

• Handle redundant notifications and abnormal user activity
• Implement online user status tracking

Once Notifications is enabled, Agora SD-RTN™ sends notification callbacks as HTTPS POST requests to your webhook when events that you are subscribed to occur. The data format of the requests is JSON, the character encoding is UTF-8, and the signature algorithm is HMAC/SHA1 or HMAC/SHA256.

For Notifications, a webhook is an endpoint on an HTTP server that handles these requests. In a production environment you write this in your web infrastructure, for development purposes best practice is to create a simple local server and use a service such as ngrok to supply a public URL that you register with Agora SD-RTN™ when you enable Notifications.

To do this, take the following steps:

1. Set up Go

   Ensure you have Go installed on your system. If not, download and install it from the official Go website.

2. Create a Go project for your server

   Create a new directory for your project and navigate into it:

   
   

   _2

   mkdir agora-webhook-server

   _2

   cd agora-webhook-server

   
   

   In the project directory, create a new file main.go. Open the file in your preferred text editor and add the following code:

   
   

   _62

   package main

   _62

   _62

   import (

   _62

   "encoding/json"

   _62

   "fmt"

   _62

   "io"

   _62

   "log"

   _62

   "net/http"

   _62

   )

   _62

   _62

   type WebhookRequest struct {

   _62

   NoticeID string `json:"noticeId"`

   _62

   ProductID int64 `json:"productId"`

   _62

   EventType int `json:"eventType"`

   _62

   Payload Payload `json:"payload"`

   _62

   }

   _62

   _62

   type Payload struct {

   _62

   ClientSeq int64 `json:"clientSeq"`

   _62

   UID int `json:"uid"`

   _62

   ChannelName string `json:"channelName"`

   _62

   }

   _62

   _62

   func rootHandler(w http.ResponseWriter, r *http.Request) {

   _62

   response := `<h1>Agora Notifications demo</h1>`

   _62

   w.WriteHeader(http.StatusOK)

   _62

   w.Write([]byte(response))

   _62

   }

   _62

   _62

   func ncsHandler(w http.ResponseWriter, r *http.Request) {

   _62

   agoraSignature := r.Header.Get("Agora-Signature")

   _62

   fmt.Println("Agora-Signature:", agoraSignature)

   _62

   _62

   body, err := io.ReadAll(r.Body)

   _62

   if err != nil {

   _62

   http.Error(w, "Unable to read request body", http.StatusBadRequest)

   _62

   return

   _62

   }

   _62

   _62

   var req WebhookRequest

   _62

   if err := json.Unmarshal(body, &req); err != nil {

   _62

   http.Error(w, "Invalid JSON", http.StatusBadRequest)

   _62

   return

   _62

   }

   _62

   _62

   fmt.Printf("Event code: %d Uid: %d Channel: %s ClientSeq: %d\n",

   _62

   req.EventType, req.Payload.UID, req.Payload.ChannelName, req.Payload.ClientSeq)

   _62

   _62

   w.WriteHeader(http.StatusOK)

   _62

   w.Write([]byte("Ok"))

   _62

   }

   _62

   _62

   func main() {

   _62

   http.HandleFunc("/", rootHandler)

   _62

   http.HandleFunc("/ncsNotify", ncsHandler)

   _62

   _62

   port := ":8080"

   _62

   fmt.Printf("Notifications webhook server started on port %s\n", port)

   _62

   if err := http.ListenAndServe(port, nil); err != nil {

   _62

   log.Fatalf("Failed to start server: %v", err)

   _62

   }

   _62

   }

   
   

3. Run your Go server

   Run the server using the following command:

   
   

   _1

   go run main.go

   
   

4. Create a public URL for your server

   In this example you use ngrok to create a public URL for your server.

   1. Download and install ngrok. If you have Chocolatey, use the following command:

      
      

      _1

      choco install ngrok

      
      

   2. Add an authtoken to ngrok:

      
      

      _1

      ngrok config add-authtoken <authToken>

      
      

      To obtain an authToken, sign up with ngrok.

   3. Start a tunnel to your local server using the following command:

      
      

      _1

      ngrok http 127.0.0.1:8080

      
      

      You see a Forwarding URL and a Web Interface URL in the console. Open the web interface URL in your browser.

5. Test the server

   Open a web browser and navigate to the public URL provided by ngrok to see the root handler response.

   Use curl, Postman, or another tool to send a POST request to https://<ngrok_url>/ncsNotify with the required JSON payload.

   Example using curl:

   
   

   _13

   curl -X POST <ngrok_url>/ncsNotify \

   _13

   -H "Content-Type: application/json" \

   _13

   -H "Agora-Signature: your_signature" \

   _13

   -d '{

   _13

   "noticeId": "some_notice_id",

   _13

   "productId": 12345,

   _13

   "eventType": 1,

   _13

   "payload": {

   _13

   "clientSeq": 67890,

   _13

   "uid": 123,

   _13

   "channelName": "test_channel"

   _13

   }

   _13

   }'

   
   

   Make sure you replace ngrok_url with the forwarding url.

   Once the HTTP request is successful, you see the following JSON payload in your browser:

   
   

   _10

   {

   _10

   "noticeId": "some_notice_id",

   _10

   "productId": 12345,

   _10

   "eventType": 1,

   _10

   "payload": {

   _10

   "clientSeq": 67890,

   _10

   "uid": 123,

   _10

   "channelName": "test_channel"

   _10

   }

   _10

   }

   
   

To enable Notifications:

1. Log in to Agora Console. On the Projects tab, locate the project for which you want to enable Notifications and click Configure.

2. In the Features section, locate Notifications, and click Enable.

3. On the configuration page, click on the service for which you want to enable notifications. The item expands to show configuration options.

4. Fill in the following information:

   • Event: Select all the events that you want to subscribe to.

     If the selected events generate a high number of queries per second (QPS), ensure that your server has sufficient processing capacity.

   • Receiving Server Region: Select the region where your server that receives the notifications is located. Agora connects to the nearest Agora node server based on your selection.

   • Receiving Server URL Endpoint: The HTTPS public address of your server that receives the notifications. For example, https://1111-123-456-789-99.ap.ngrok.io/ncsNotify.

     info

     For enhanced security, Notifications no longer supports HTTP addresses.

     • To reduce the delay in notification delivery, best practice is to activate HTTP persistent connection (also called HTTP keep-alive) on your server with the following settings:

       • MaxKeepAliveRequests: 100 or more
       • KeepAliveTimeout: 10 seconds or more

   • Whitelist: If your server is behind a firewall, check the box here, and ensure that you call the IP address query API to get the IP addresses of the Agora Notifications server and add them to the firewall's allowed IP list.

5. Copy the Secret displayed against the product name by clicking the copy icon. You use this secret to Add signature verification.

6. Press Save. Agora performs a health test for your configuration as follows:

   1. The Notifications health test generates test events that correspond to your subscribed events, and then sends test event callbacks to your server.

      In test event callbacks, the channelName is test_webhook, and the uid is 12121212.

   2. After receiving each test event callback, your server must respond within 10 seconds with a status code of 200. The response body must be in JSON format.

   3. When the Notifications health test succeeds, read the prompt and press Save Notifications Configuration. After your configuration is saved, the Status of Notifications shows Enabled.

      If the Notifications health test fails, follow the prompt on the Agora Console to troubleshoot the error. Common errors include the following:

      • Request timeout (590): Your server does not return the status code 200 within 10 seconds. Check whether your server responds to the request properly. If your server responds to the request properly, contact Agora Technical Support to check if the network connection between the Agora Notifications server and your server is working.

      • Domain name unreachable (591): The domain name is invalid and cannot be resolved to the target IP address. Check whether your server is properly deployed.

      • Certificate error (592): The Agora Notifications server fails to verify the SSL certificates returned by your server. Check if the SSL certificates of your server are valid. If your server is behind a firewall, check whether you have added all IP addresses of the Agora Notifications server to the firewall's allowed IP list.

      • Other response errors: Your server returns a response with a status code other than 200. See the prompt on the Agora Console for the specific status code and error messages.

To communicate securely between Notifications and your webhook, Agora SD-RTN™ uses signatures for identity verification as follows:

1. When you configure Notifications in Agora Console, Agora SD-RTN™ generates a secret you use for verification.

2. When sending a notification, Notifications generates two signature values from the secret using HMAC/SHA1 and HMAC/SHA256 algorithms. These signatures are added as Agora-Signature and Agora-Signature-V2 to the HTTPS request header.

3. When your server receives a callback, you can verify Agora-Signature or Agora-Signature-V2:

   • To verify Agora-Signature, use the secret, the raw request body, and the crypto/sha1 algorithm.
   • To verify Agora-Signature-V2, use the secret, the raw request body, and the crypto/sha256 algorithm.

The following sample code uses crypto/sha1.

To add signature verification to your server, take the following steps:

1. In the main.go file, replace your imports with with the following:

   
   

   _10

   import (

   _10

   "crypto/hmac"

   _10

   "crypto/sha1"

   _10

   "encoding/hex"

   _10

   "encoding/json"

   _10

   "fmt"

   _10

   "io"

   _10

   "log"

   _10

   "net/http"

   _10

   )

   
   

2. Add the following code after the list of imports:

   
   

   _17

   // Replace with your NCS secret

   _17

   const secret = "<Replace with your secret code>"

   _17

   _17

   // calcSignatureV1 computes the HMAC/SHA256 signature for a given payload and secret

   _17

   func calcSignatureV1(secret, payload string) string {

   _17

   mac := hmac.New(sha1.New, []byte(secret))

   _17

   mac.Write([]byte(payload))

   _17

   return hex.EncodeToString(mac.Sum(nil))

   _17

   }

   _17

   _17

   // verify checks if the provided signature matches the HMAC/SHA256 signature of the request body

   _17

   func verify(requestBody, signature string) bool {

   _17

   calculatedSignature := calcSignatureV1(secret, requestBody)

   _17

   fmt.Println("Calculated Signature:", calculatedSignature)

   _17

   fmt.Println("Received Signature:", signature)

   _17

   return calculatedSignature == signature

   _17

   }

   
   

3. In the main.go file, add the following code after fmt.Println("Request Body:", string(body)):

   
   

   _5

   // Verify the signature

   _5

   if !verify(string(body), agoraSignature) {

   _5

   http.Error(w, "Invalid signature", http.StatusUnauthorized)

   _5

   return

   _5

   }

   
   

4. To test the server, follow the steps given in the Enable notifications section.

5. When you receive an event from the console, and if the signature matches, the event details are displayed in your browser.

When using Notifications to maintain the online status of your app users, your server might experience the following issues:

• Message notifications are redundant. You receive multiple notifications because the Agora Notifications server can send more than one notification callback for each channel event to ensure reliability of the service.

• Message notifications arrive out of order. Network issues cause callbacks to arrive at your server in a different order than the order of event occurrence.

To accurately maintain the online status of users, your server needs to be able to deal with redundant notifications and handle received notifications in the same order as events occur. The following section shows you how to use channel event callbacks to accomplish this.

Agora Notifications sends RTC channel event callbacks to your server. All channel events, except for 101 and 102 events, contain the clientSeq field (Unit64) in payload, which represents the sequence number of an event. This field is used to identify the order in which events occur on the app client. For notification callbacks reporting the activities of the same user, the value of the clientSeq field increases as events happen.

Refer to the following steps to use the clientSeq field to enable your server to handle redundant messages, and messages arriving out of order:

1. Enable Agora Notifications, and subscribe to RTC channel event callbacks. Best practice is to subscribe to the following event types according to your scenario:

   • In the LIVE_BROADCASTING profile: 103, 104, 105, 106, 111, and 112.
   • In the COMMUNICATION profile: 103, 104, 111, and 112.

2. Use the channel event callbacks to get the latest status updates about the following at your server:

   • Channel lists
   • User lists in each channel
   • Data for each user, including the user ID, user role, whether the user is in a channel, and clientSeq of channel events

3. When receiving notification callbacks of a user, search for the user in the user lists. If there is no data for the user, create data specific to the user.

4. Compare the value in the clientSeq field of the latest notification callback you receive with that of the last notification callback handled by your server:

   • If the former is greater than the latter, the notification callback needs to be handled.
   • If the former is less than the latter, the notification callback should be ignored.

5. When receiving notification callbacks reporting a user leaving a channel, wait for one minute before deleting the user data. If it is deleted immediately, your server cannot handle notifications in the same order as channel events happen when receiving redundant notifications or notifications out of order.

When your server receives a notification callback of event 104 with reason as 999, it means that the user is considered to have abnormal activities due to frequent login and logout actions. In this case, best practice is that your server calls the Banning user privileges API to remove the user from the current channel one minute after receiving such notification callback; otherwise, the notification callbacks your server receives about the user's events might be redundant or arrive out of order, which makes it hard for you to accurately maintain the online status of this user.

This section provides sample Go code to show how to use channel event callbacks to maintain online user status at your app server.

To maintain a user registry, take the following steps:

1. Replace the content of the main.go file with the following code:

   
   

   _216

   package main

   _216

   _216

   import (

   _216

   "crypto/hmac"

   _216

   "crypto/sha1"

   _216

   "encoding/hex"

   _216

   "encoding/json"

   _216

   "fmt"

   _216

   "io"

   _216

   "log"

   _216

   "net/http"

   _216

   "sync"

   _216

   "time"

   _216

   )

   _216

   _216

   const secret = "<Add Your secret key here>"

   _216

   _216

   type WebhookRequest struct {

   _216

   NoticeID string `json:"noticeId"`

   _216

   ProductID int64 `json:"productId"`

   _216

   EventType int `json:"eventType"`

   _216

   Payload Payload `json:"payload"`

   _216

   }

   _216

   _216

   type Payload struct {

   _216

   ClientSeq int64 `json:"clientSeq"`

   _216

   UID int `json:"uid"`

   _216

   ChannelName string `json:"channelName"`

   _216

   }

   _216

   _216

   const (

   _216

   EventBroadcasterJoin = 103

   _216

   EventBroadcasterQuit = 104

   _216

   EventAudienceJoin = 105

   _216

   EventAudienceQuit = 106

   _216

   EventChangeRoleToBroadcaster = 111

   _216

   EventChangeRoleToAudience = 112

   _216

   _216

   RoleBroadcaster = 1

   _216

   RoleAudience = 2

   _216

   WaitTimeoutMs = 60 * 1000

   _216

   )

   _216

   _216

   var (

   _216

   channels = make(map[string]*Channel)

   _216

   mu sync.Mutex

   _216

   )

   _216

   _216

   type User struct {

   _216

   UID int

   _216

   Role int

   _216

   IsOnline bool

   _216

   LastClientSeq int64

   _216

   }

   _216

   _216

   type Channel struct {

   _216

   Users map[int]*User

   _216

   }

   _216

   _216

   func handleNCSEvent(channelName string, uid int, eventType int, clientSeq int64) {

   _216

   mu.Lock()

   _216

   defer mu.Unlock()

   _216

   _216

   if !isValidEventType(eventType) {

   _216

   return

   _216

   }

   _216

   _216

   isOnlineInNotice := isUserOnlineInNotice(eventType)

   _216

   roleInNotice := getUserRoleInNotice(eventType)

   _216

   _216

   channel, exists := channels[channelName]

   _216

   if !exists {

   _216

   channel = &Channel{Users: make(map[int]*User)}

   _216

   channels[channelName] = channel

   _216

   fmt.Println("New channel", channelName, "created")

   _216

   }

   _216

   _216

   user, exists := channel.Users[uid]

   _216

   if !exists {

   _216

   user = &User{UID: uid, Role: roleInNotice, IsOnline: isOnlineInNotice, LastClientSeq: clientSeq}

   _216

   channel.Users[uid] = user

   _216

   _216

   if isOnlineInNotice {

   _216

   fmt.Println("New User", uid, "joined channel", channelName)

   _216

   } else {

   _216

   delayedRemoveUserFromChannel(channelName, uid, clientSeq)

   _216

   }

   _216

   } else if clientSeq > user.LastClientSeq {

   _216

   user.Role = roleInNotice

   _216

   user.IsOnline = isOnlineInNotice

   _216

   user.LastClientSeq = clientSeq

   _216

   _216

   if !isOnlineInNotice && user.IsOnline {

   _216

   fmt.Println("User", uid, "quit channel", channelName)

   _216

   delayedRemoveUserFromChannel(channelName, uid, clientSeq)

   _216

   }

   _216

   }

   _216

   }

   _216

   _216

   func delayedRemoveUserFromChannel(channelName string, uid int, clientSeq int64) {

   _216

   time.AfterFunc(WaitTimeoutMs*time.Millisecond, func() {

   _216

   mu.Lock()

   _216

   defer mu.Unlock()

   _216

   _216

   channel, exists := channels[channelName]

   _216

   if !exists {

   _216

   return

   _216

   }

   _216

   _216

   user, exists := channel.Users[uid]

   _216

   if !exists {

   _216

   return

   _216

   }

   _216

   _216

   if user.LastClientSeq != clientSeq {

   _216

   return

   _216

   }

   _216

   _216

   if !user.IsOnline {

   _216

   delete(channel.Users, uid)

   _216

   fmt.Println("Removed user", uid, "from channel", channelName)

   _216

   } else {

   _216

   fmt.Println("User", uid, "is online while delayed removing, cancelled")

   _216

   }

   _216

   _216

   if len(channel.Users) == 0 {

   _216

   delete(channels, channelName)

   _216

   fmt.Println("Removed channel", channelName)

   _216

   }

   _216

   })

   _216

   }

   _216

   _216

   func isValidEventType(eventType int) bool {

   _216

   return eventType == EventBroadcasterJoin ||

   _216

   eventType == EventBroadcasterQuit ||

   _216

   eventType == EventAudienceJoin ||

   _216

   eventType == EventAudienceQuit ||

   _216

   eventType == EventChangeRoleToBroadcaster ||

   _216

   eventType == EventChangeRoleToAudience

   _216

   }

   _216

   _216

   func isUserOnlineInNotice(eventType int) bool {

   _216

   return eventType == EventBroadcasterJoin ||

   _216

   eventType == EventAudienceJoin ||

   _216

   eventType == EventChangeRoleToBroadcaster ||

   _216

   eventType == EventChangeRoleToAudience

   _216

   }

   _216

   _216

   func getUserRoleInNotice(eventType int) int {

   _216

   if eventType == EventBroadcasterJoin ||

   _216

   eventType == EventBroadcasterQuit ||

   _216

   eventType == EventChangeRoleToBroadcaster {

   _216

   return RoleBroadcaster

   _216

   }

   _216

   return RoleAudience

   _216

   }

   _216

   _216

   func calcSignature(secret, payload string) string {

   _216

   mac := hmac.New(sha1.New, []byte(secret))

   _216

   mac.Write([]byte(payload))

   _216

   return hex.EncodeToString(mac.Sum(nil))

   _216

   }

   _216

   _216

   func verifySignature(requestBody, signature string) bool {

   _216

   calculatedSignature := calcSignature(secret, requestBody)

   _216

   fmt.Println("Calculated Signature:", calculatedSignature)

   _216

   fmt.Println("Received Signature:", signature)

   _216

   return calculatedSignature == signature

   _216

   }

   _216

   _216

   func rootHandler(w http.ResponseWriter, r *http.Request) {

   _216

   response := `<h1>Agora Notifications demo</h1><h2>Port: 80</h2>`

   _216

   w.WriteHeader(http.StatusOK)

   _216

   w.Write([]byte(response))

   _216

   }

   _216

   _216

   func ncsHandler(w http.ResponseWriter, r *http.Request) {

   _216

   agoraSignature := r.Header.Get("Agora-Signature")

   _216

   fmt.Println("Agora-Signature:", agoraSignature)

   _216

   _216

   body, err := ioutil.ReadAll(r.Body)

   _216

   if err != nil {

   _216

   http.Error(w, "Unable to read request body", http.StatusBadRequest)

   _216

   return

   _216

   }

   _216

   _216

   if !verifySignature(string(body), agoraSignature) {

   _216

   http.Error(w, "Invalid signature", http.StatusUnauthorized)

   _216

   return

   _216

   }

   _216

   _216

   var req WebhookRequest

   _216

   if err := json.Unmarshal(body, &req); err != nil {

   _216

   http.Error(w, "Invalid JSON", http.StatusBadRequest)

   _216

   return

   _216

   }

   _216

   _216

   fmt.Printf("Event code: %d Uid: %d Channel: %s ClientSeq: %d\n",

   _216

   req.EventType, req.Payload.UID, req.Payload.ChannelName, req.Payload.ClientSeq)

   _216

   _216

   handleNCSEvent(req.Payload.ChannelName, req.Payload.UID, req.EventType, req.Payload.ClientSeq)

   _216

   _216

   w.WriteHeader(http.StatusOK)

   _216

   w.Write([]byte("Ok"))

   _216

   }

   _216

   _216

   func main() {

   _216

   http.HandleFunc("/", rootHandler)

   _216

   http.HandleFunc("/ncsNotify", ncsHandler)

   _216

   _216

   port := ":80"

   _216

   fmt.Printf("Notifications webhook server started on port %s\n", port)

   _216

   if err := http.ListenAndServe(port, nil); err != nil {

   _216

   log.Fatalf("Failed to start server: %v", err)

   _216

   }

   _216

   }

   
   

2. To test signature verification, follow the steps given in the Enable notifications section.

When adopting the solutions recommended by Agora to maintain user online status, you need to recognize the following:

• The solutions only guarantee eventual consistency of user status.

• To improve accuracy, notification callbacks specific to one channel must be handled in a single process.

This section contains in depth information about Notifications.

The header of notification callbacks contains the following fields:

Field name	Value
Content-Type	application/json
Agora-Signature	The signature generated by Agora using the Secret and the HMAC/SHA1 algorithm. You need to use the Secret and HMAC/SHA1 algorithm to verify the signature value. For details, see Signature verification.
Agora-Signature-V2	The signature generated by Agora using the Secret and the HMAC/SHA256 algorithm. You need to use the Secret and the HMAC/SHA256 algorithm to verify the signature value. For details, see Signature verification.

The request body of notification callbacks contains the following fields:

Field name	Type	Description
noticeId	String	The notification ID, identifying the notification callback when the event occurs.
productId	Number	The product ID: 1: Realtime Communication (RTC) service 3: Cloud Recording 4: Media Pull 5: Media Push
eventType	Number	The type of event being notified. For details, see event types.
notifyMs	Number	The Unix timestamp (ms) when Notifications sends a callback to your server. This value is updated when Notifications resends the notification callback.
payload	JSON Object	The content of the event being notified. The payload varies with event type.

_9

{

_9

"noticeId":"2000001428:4330:107",

_9

"productId":1,

_9

"eventType":101,

_9

"notifyMs":1611566412672,

_9

"payload":{

_9

...

_9

}

_9

}

The Agora Notifications server notifies your server of the following RTC channel event types when you use the RTC service:

eventType	Event name	Description
101	channel create	Initializes the channel.
102	channel destroy	Destroys the channel.
103	broadcaster join channel	In the streaming profile, the host joins the channel.
104	broadcaster leave channel	In the streaming profile, the host leaves the channel.
105	audience join channel	In the streaming profile, an audience member joins the channel.
106	audience leave channel	In the streaming profile, an audience member leaves the channel.
107	user join channel with communication mode	In the communication profile, a user joins the channel.
108	user leave channel with communication mode	In the communication profile, a user leaves the channel.
111	client role change to broadcaster	In the communication profile in RTC v4. x products or in the streaming profile, an audience member switches their user role to host.
112	client role change to audience	In the communication profile in RTC v4. x products or in the streaming profile, a host switches their user role to audience member.

This event type indicates that a channel is initialized (when the first user joins the channel). The payload contains the following fields:

Field name	Type	Description
channelName	String	The name of the channel.
ts	Number	The Unix timestamp (s) when the event occurs on the Agora RTC server.

_4

{

_4

"channelName":"test_webhook",

_4

"ts":1560399999

_4

}

This event type indicates that the last user in the channel leaves the channel and the channel is destroyed. The payload contains the following fields:

Field name	Type	Description
channelName	String	The name of the channel.
ts	Number	The Unix timestamp (s) when the event occurs on the Agora RTC server.

_4

{

_4

"channelName":"test_webhook",

_4

"ts":1560399999

_4

}

This event type indicates that a host joins the channel in the streaming profile. The payload contains the following fields:

Field name	Type	Description
channelName	String	The name of the channel.
uid	Number	The user ID of the host in the channel.
platform	Number	The platform type of the host's device: 1: Android 2: iOS 5: Windows 6: Linux 7: Web 8: macOS 0: Other platform
clientType	Number	The type of services used by the host on Linux. Common return values include: 3: On-premise Recording 10: Cloud Recording This field is only returned when platform is 6.
clientSeq	Number	The sequence number, which is used to identify the order in which events occur on the app client. You can use the value of this field to sort the events of a user into chronological order.
ts	Number	The Unix timestamp (s) when the event occurs on the Agora RTC server.

_7

{

_7

"channelName":"test_webhook",

_7

"uid":12121212,

_7

"platform":1,

_7

"clientSeq":1625051030746,

_7

"ts":1560396843

_7

}

This event type indicates that a host leaves the channel in the streaming profile. The payload contains the following fields:

Field name	Type	Description
channelName	String	The name of the channel.
uid	Number	The user ID of the host in the channel.
platform	Number	The platform type of the host's device: 1: Android 2: iOS 5: Windows 6: Linux 7: Web 8: macOS 0: Other platform
clientType	Number	The type of services used by the host on Linux. Common return values include: 3: On-premise Recording 10: Cloud Recording This field is only returned when platform is 6.
clientSeq	Number	The sequence number, which is used to identify the order in which events occur on the app client. You can use the value of this field to sort the events of a user into chronological order.
reason	Number	The reason why the host leaves the channel: 1: The host quits the call. 2: The connection between the app client and the Agora RTC server times out, which occurs when the Agora SD-RTN does not receive any data packets from the app client for more than 10 seconds. 3: Permission issues. For example, the host is kicked out of the channel by the administrator through the Banning user privileges RESTful API. 4: Internal issues with the Agora RTC server. For example, the Agora RTC server disconnects from the app client for a short period of time for load balancing. When the load balancing is finished, the Agora RTC server reconnects with the client. 5: The host uses a new device to join the channel, which forces the old device to leave the channel. 9: The app client has multiple IP addresses, therefore the SDK actively disconnects from the Agora RTC server and reconnects. The user is not aware of this process. Check whether the app client has multiple public IP addresses or uses a VPN 10: Due to network connection issues, for example, the SDK does not receive any data packets from the Agora RTC server for more than 4 seconds or the socket connection error occurs, the SDK actively disconnects from the Agora server and reconnects. The user is not aware of this process. Check the network connection status. 999: The user has unusual activities, such as frequent login and logout actions. 60 seconds after receiving the 104 or 106 event callback with reason as 999, your app server needs to call the Banning user privileges API to remove the user from the current channel; otherwise, your server could fail to receive any notification callbacks about the user's events if the user rejoins the channel. 0: Other reasons.
ts	Number	The Unix timestamp (s) when the event occurs on the Agora RTC server.
duration	Number	The length of time (s) that the host stays in the channel.

_9

{

_9

"channelName":"test_webhook",

_9

"uid":12121212,

_9

"platform":1,

_9

"clientSeq":1625051030789,

_9

"reason":1,

_9

"ts":1560396943,

_9

"duration":600

_9

}

This event type indicates that an audience member joins the channel in the streaming profile The payload includes the following fields:

Field name	Type	Description
channelName	String	The name of the channel.
uid	Number	The user ID of the audience member in the channel.
platform	Number	The platform type of the audience member's device: 1: Android 2: iOS 5: Windows 6: Linux 7: Web 8: macOS 0: Other platform
clientType	Number	The type of services used by the host on Linux. Common return values include: 3: On-premise Recording 10: Cloud Recording This field is only returned when platform is 6.
clientSeq	Number	The sequence number, which is used to identify the order in which events occur on the app client. You can use the value of this field to sort the events of a user into chronological order.
ts	Number	The Unix timestamp (s) when the event occurs on the Agora RTC server.

_7

{

_7

"channelName":"test_webhook",

_7

"uid":12121212,

_7

"platform":1,

_7

"clientSeq":1625051035346,

_7

"ts":1560396843

_7

}

This event type indicates that an audience member leaves the channel in the streaming profile. The payload includes the following fields:

Field name	Type	Description
channelName	String	The name of the channel.
uid	Number	The user ID of the audience member in the channel.
platform	Number	The platform type of the audience member's device: 1: Android 2: iOS 5: Windows 6: Linux 7: Web 8: macOS 0: Other platform
clientType	Number	The type of services used by the audience member on Linux. Common return values include: 3: On-premise Recording 10: Cloud Recording This field is only returned when platform is 6.
clientSeq	Number	The sequence number, which is used to identify the order in which events occur on the app client. You can use the value of this field to sort the events of a user into chronological order.
reason	Number	The reason why the audience member leaves the channel: 1: The audience member quits the call. 2: The connection between the app client and the Agora RTC server times out, which occurs when the Agora SD-RTN does not receive any data packets from the app client for more than 10 seconds. 3: Permission issues. For example, the audience member is kicked out of the channel by the administrator through the Banning user privileges RESTful API. 4: Internal issues with the Agora RTC server. For example, the Agora RTC server disconnects from the app client for a short period of time for load balancing. When the load balancing is finished, the Agora RTC server reconnects with the client. 5: The audience member uses a new device to join the channel, which forces the old device to leave the channel. 9: The app client has multiple IP addresses, therefore the SDK actively disconnects from the Agora RTC server and reconnects. The user is not aware of this process. Check whether the app client has multiple public IP addresses or uses a VPN 10: Due to network connection issues, for example, the SDK does not receive any data packets from the Agora RTC server for more than 4 seconds or the socket connection error occurs, the SDK actively disconnects from the Agora server and reconnects. The user is not aware of this process. Check the network connection status. 999: The user has unusual activities, such as frequent login and logout actions. 60 seconds after receiving the 104 or 106 event callback with reason as 999, your app server needs to call the Banning user privileges API to remove the user from the current channel; otherwise, your server could fail to receive any notification callbacks about the user's events if the user rejoins the channel. 0: Other reasons.
ts	Number	The Unix timestamp (s) when the event occurs on the Agora RTC server.
duration	Number	The length of time (s) that the audience member stays in the channel.

_9

{

_9

"channelName":"test_webhook",

_9

"uid":12121212,

_9

"platform":1,

_9

"clientSeq":1625051035390,

_9

"reason":1,

_9

"ts":1560396943,

_9

"duration":600

_9

}

This event type indicates that a user joins the channel in the communication profile. The payload includes the following fields:

Field name	Type	Description
channelName	String	The name of the channel.
uid	Number	The user ID of the user in the channel.
platform	Number	The platform type of the host's device: 1: Android 2: iOS 5: Windows 6: Linux 7: Web 8: macOS 0: Other platform
clientSeq	Number	The sequence number, which is used to identify the order in which events occur on the app client. You can use the value of this field to sort the events of a user into chronological order.
ts	Number	The Unix timestamp (s) when the event occurs on the Agora RTC server.

_7

{

_7

"channelName":"test_webhook",

_7

"uid":12121212,

_7

"platform":1,

_7

"clientSeq":1625051035369,

_7

"ts":1560396834

_7

}

This event type indicates that a user leaves the channel in the communication profile. The payload includes the following fields:

Field name	Type	Description
channelName	String	The name of the channel.
uid	Number	The user ID of the user in the channel.
platform	Number	The platform type of the user's device: 1: Android 2: iOS 5: Windows 6: Linux 7: Web 8: macOS 0: Other platform
clientSeq	Number	The sequence number, which is used to identify the order in which events occur on the app client. You can use the value of this field to sort the events of a user into chronological order.
reason	Number	The reason why a user leaves the channel: 1: The user quits the call. 2: The connection between the app client and the Agora RTC server times out, which occurs when the Agora SD-RTN does not receive any data packets from the app client for more than 10 seconds. 3: Permission issues. For example, the user is kicked out of the channel by the administrator through the Banning user privileges RESTful API. 4: Internal issues with the Agora RTC server. For example, the Agora RTC server disconnects from the app client for a short period of time for load balancing. When the load balancing is finished, the Agora RTC server reconnects with the client. 5: The user uses a new device to join the channel, which forces the old device to leave the channel. 9: The app client has multiple IP addresses, therefore the SDK actively disconnects from the Agora RTC server and reconnects. The user is not aware of this process. Check whether the app client has multiple public IP addresses or uses a VPN 10: Due to network connection issues, for example, the SDK does not receive any data packets from the Agora RTC server for more than 4 seconds or the socket connection error occurs, the SDK actively disconnects from the Agora server and reconnects. The user is not aware of this process. Check the network connection status. 999: The user has unusual activities, such as frequent login and logout actions. 60 seconds after receiving the 104 or 106 event callback with reason as 999, your app server needs to call the Banning user privileges API to remove the user from the current channel; otherwise, your server could fail to receive any notification callbacks about the user's events if the user rejoins the channel. 0: Other reasons.
ts	Number	The Unix timestamp (s) when the event occurs on the Agora RTC server.
duration	Number	The length of time (s) that the user stays in the channel.

_9

{

_9

"channelName":"test_webhook",

_9

"uid":12121212,

_9

"platform":1,

_9

"clientSeq":1625051037369,

_9

"reason":1,

_9

"ts":1560496834,

_9

"duration":600

_9

}

This event type indicates that an audience member calls setClientRole to switch their user role to host in the streaming profile. The payload includes the following fields:

Field name	Type	Description
channelName	String	The name of the channel.
uid	Number	The user ID of the user in the channel.
clientSeq	Number	The sequence number, which is used to identify the order in which events occur on the app client. You can use the value of this field to sort the events of a user into chronological order.
ts	Number	The Unix timestamp (s) when the event occurs on the Agora RTC server.

_6

{

_6

"channelName":"test_webhook",

_6

"uid":12121212,

_6

"clientSeq":1625051035469,

_6

"ts":1560396834

_6

}

This event type indicates that a host call setClientRole to switch their user role to audience member in the streaming profile. The payload contains the following fields:

Field name	Type	Description
channelName	String	The name of the channel.
uid	Number	The user ID of the user in the channel.
clientSeq	Number	The sequence number, which is used to identify the order in which events occur on the app client. You can use the value of this field to sort the events of a user into chronological order.
ts	Number	The Unix timestamp (s) when the event occurs on the Agora RTC server.

_6

{

_6

"channelName":"test_webhook",

_6

"uid":12121212,

_6

"clientSeq":16250510358369,

_6

"ts":1560496834

_6

}

If your server that receives notification callbacks is behind a firewall, call the IP address query API to retrieve the IP addresses of Notifications and configure your firewall to trust all these IP addresses.

Agora occasionally adjusts the Notifications IP addresses. Best practice is to call this endpoint at least every 24 hours and automatically update the firewall configuration.

• Method: GET
• Endpoint: https://api.agora.io/v2/ncs/ip

Authorization: You must generate a Base64-encoded credential with the Customer ID and Customer Secret provided by Agora, and then pass the credential to the Authorization field in the HTTP request header.

This API has no body parameters.

When the request succeeds, the response body looks like the following:

_14

{

_14

"data": {

_14

"service": {

_14

"hosts": [

_14

{

_14

"primaryIP": "xxx.xxx.xxx.xxx"

_14

},

_14

{

_14

"primaryIP": "xxx.xxx.xxx.xxx"

_14

}

_14

]

_14

}

_14

}

_14

}

Each primary IP field shows an IP address of Notifications server. When you receive a response, you need to note the primary IP fields and add all these IP addresses to your firewall's allowed IP list.

• Notifications does not guarantee that notification callbacks arrive at your server in the same order as events occur. Implement a strategy to handle messages arriving out of order.

• For improved reliability of Notifications, your server may receive more than one notification callback for a single event. Your server must be able to handle repeated messages.

  Tip

  To implement a strategy to ensure that you log only one callback event and ignore duplicate events, use a combination of the noticeId and notifyMs fields in the response body.