Instant Messaging (IM) is a stable messaging service based on the communication technology provided by CommsEase. You can use IM to build robust chatting features for your apps. NIM SDK for Flutter offers a full-fledged instant messaging framework using Flutter, encapsulates internal complexitiess, and provideseasy-to-use APIs to facilitate quickly integration with third-party applications. You can use NIM SDK for Flutter to build Android, iOS, Windows, and macOS applications.

• NimCore Class can initialize the SDK and get functionalities of other subclasses.
• AuthService class provides the authentication interface, including login and logout.
• UserService class provides the user service.
• MessageService class provides the messaging service.
• EventSubscribeService class manages the event subscription service.
• SystemMessageService class provides the system notification service.
• TeamService class provides the group chat service.
• ChatroomService class contains APIs for the chat room service.
• NOSService class provides the NOS storage service.
• AudioService class provides the audio service.
• SettingsService class provides interfaces for settings.
• PassThroughService class provides the data transmission service in pass-through mode.

The SDK may return error codes and warning codes during API calls. For more information, see Error codes and warning codes.

NimCore

Method/property	Description	SDK version
instance	Get a global SDK instance.	V1.0.0
initialize	Initialize the SDK	V1.0.0
authService	Get the authentication service	V1.0.0
userService	Get the user service	V1.0.0
messageService	Get the messaging service	V1.0.0
eventSubscribeService	Get the event subscription service	V1.0.0
chatroomService	Get the chat room service	V1.0.0
audioService	Get the audio service.	V1.0.0
teamService	Get the group chat service.	V1.0.0
systemMessageService	Get the system messaging service.	V1.0.0
settingsService	Get the settings service.	V1.0.0
nosService	Get the NOS storage service.	V1.0.0
passThroughService	Get the data transmission service in pass-through mode.	V1.0.0

AuthService

Method/property	Description	SDK version
login	Log in to the system	V1.0.0
logout	Log out of the system	V1.0.0
kickOutOtherOnlineClient	Invalidate login sessions on other clients.	V1.0.0
authStatus	Login status event stream	V1.0.0
onlineClients	Multi-device login event stream	V1.0.0
dynamicTokenProvider	Set the token provider for dynamic login	V1.0.0

UserService

Method/property	Description	SDK version
addFriend	Add a friend	V1.0.0
deleteFriend	Delete a friend	V1.0.0
getFriendList	Get the friends list	V1.0.0
updateMyUserInfo	Update the profile	V1.0.0

MessageService

Method/property	Description	SDK version
sendMessage	Send a message	V1.0.0
searchMessage	Search for a message	V1.0.0
replyMessage	Reply a message.	V1.0.0
revokeMessage	Recall a message	V1.0.0
pullMessageHistory	Retrieve the message history.	V1.0.0
onMessage	Event stream of receiving a message	V1.0.0
onMessageStatus	Event stream of message status changes	V1.0.0

TeamService

Method/property	Description	SDK version
createTeam	Create a group chat	V1.0.0
dismissTeam	Dismiss a group	V1.0.0
queryTeam	Query the group profile	V1.0.0
applyJoinTeam	Request to join a group	V1.0.0
acceptInvite	Accept an invitation to join a group.	V1.0.0
quitTeam	Leave a group	V1.0.0
passApply	Approve a join request	V1.0.0
removeMembers	Remove members from a group	V1.0.0

ChatroomService

Method/property	Description	SDK version
enterChatroom	Join a chat room	V1.0.0
exitChatroom	Leave a chat room	V1.0.0
fetchChatroomInfo	Get the profile of a chat room	V1.0.0
fetchChatroomMembers	Get the members of a chat room.	V1.0.0
fetchMessageHistory	Retrieve the message history of a chat room.	V1.0.0
sendChatroomMessage	Send a message in a chat room	V1.0.0
onMessageReceived	Event stream of receiving messages in a chat room	V1.0.0

EventSubscribeService

Method/property	Description	SDK version
registerEventSubscribe	Register the event of subscribing to the online status of a specified account.	V1.0.0
unregisterEventSubscribe	Unregister the event of subscribing to the online status of a specified account.	V1.0.0
publishEvent	Publish the event to subscribers	V1.0.0
eventSubscribeStream	Event stream of receiving events	V1.0.0

SystemMessageService

Method/property	Description	SDK version
querySystemMessageUnread	Get the unread system messages.	V1.0.0
clearSystemMessages	Delete all system messages.	V1.0.0
sendCustomNotification	Send a custom system notification	V1.0.0
onCustomNotification	Called when receiving a system notification	V1.0.0

NOSService

Method/property	Description	SDK version
upload	Upload an attachment	V1.0.0
onNOSTransferProgress	Event stream of transfer progress	V1.0.0
onNOSTransferStatus	Status event stream	V1.0.0

AudioService

Method/property	Description	SDK version
startRecord	Start audio recording	V1.0.0
stopRecord	Stop audio recording	V1.0.0
onAudioRecordStatus	Event stream of recording status	V1.0.0

SettingsService

Method/property	Description	SDK version
enableNotificationAndroid	Message alert configuration (Android)	V1.0.0
enablePushServiceAndroid	Enable or disable push notifications (Android)	V1.0.0
updateAPNSToken	Update iOS deviceToken	V1.0.0
uploadLogs	Upload logs	V1.0.0

PassThroughService

Method/property	Description	SDK version
httpProxy	Send an HTTP proxy request	V1.0.0