diff --git a/src/core/http.ts b/src/core/http.ts
index a9ae9ef..876a410 100644
--- a/src/core/http.ts
+++ b/src/core/http.ts
@@ -42,6 +42,22 @@ async function request<T>(
   return json.data
 }
 
+export async function uploadFile(file: File): Promise<{ url: string; thumbnailUrl?: string; hash: string; size: number; originalName: string; mimeType: string; ext: string }> {
+  const token = _tokenGetter()
+  const formData = new FormData()
+  formData.append('file', file)
+
+  const res = await fetch(`${_baseUrl}/api/file/upload`, {
+    method: 'POST',
+    headers: token ? { Authorization: `Bearer ${token}` } : {},
+    body: formData,
+  })
+
+  const json: ApiResponse<unknown> = await res.json()
+  if (json.code !== 200) throw new Error(json.message)
+  return json.data as { url: string; thumbnailUrl?: string; hash: string; size: number; originalName: string; mimeType: string; ext: string }
+}
+
 export const http = {
   get: <T>(path: string, query?: Record<string, QueryValue>) => request<T>('GET', path, undefined, query),
   post: <T>(path: string, body?: unknown, query?: Record<string, QueryValue>) => request<T>('POST', path, body, query),
diff --git a/src/im/ImClient.ts b/src/im/ImClient.ts
index cf6d5c5..6fdd89a 100644
--- a/src/im/ImClient.ts
+++ b/src/im/ImClient.ts
@@ -140,6 +140,7 @@ export class ImClient {
             // Don't return early — also emit as message for consistency with old behavior
           }
           this.emit('message', message)
+          this.emit('conversations')
         } catch {
           // ignore malformed frames
         }
diff --git a/src/im/api.ts b/src/im/api.ts
index 3a05062..88b7c61 100644
--- a/src/im/api.ts
+++ b/src/im/api.ts
@@ -1,5 +1,5 @@
 import { getConfig } from '../core/sdk'
-import { http } from '../core/http'
+import { http, uploadFile } from '../core/http'
 import type {
   BlacklistCheckResult,
   BlacklistEntry,
@@ -39,6 +39,48 @@ export function sendMessage(params: { toId: string; chatType: ChatType; msgType:
   return http.post<ImMessage>('/api/im/messages/send', params, appQuery())
 }
 
+export async function sendImageMessage(toId: string, chatType: ChatType, file: File, width?: number, height?: number): Promise<ImMessage> {
+  const result = await uploadFile(file)
+  const content = JSON.stringify({
+    url: result.url,
+    ...(width !== undefined ? { width } : {}),
+    ...(height !== undefined ? { height } : {}),
+    ...(result.thumbnailUrl ? { thumbnailUrl: result.thumbnailUrl } : {}),
+  })
+  return sendMessage({ toId, chatType, msgType: 'IMAGE', content })
+}
+
+export async function sendVideoMessage(toId: string, chatType: ChatType, file: File, width?: number, height?: number, duration?: number): Promise<ImMessage> {
+  const result = await uploadFile(file)
+  const content = JSON.stringify({
+    url: result.url,
+    ...(width !== undefined ? { width } : {}),
+    ...(height !== undefined ? { height } : {}),
+    ...(duration !== undefined ? { duration } : {}),
+    ...(result.thumbnailUrl ? { thumbnailUrl: result.thumbnailUrl } : {}),
+  })
+  return sendMessage({ toId, chatType, msgType: 'VIDEO', content })
+}
+
+export async function sendFileMessage(toId: string, chatType: ChatType, file: File): Promise<ImMessage> {
+  const result = await uploadFile(file)
+  const content = JSON.stringify({
+    url: result.url,
+    name: result.originalName,
+    size: result.size,
+  })
+  return sendMessage({ toId, chatType, msgType: 'FILE', content })
+}
+
+export async function sendAudioMessage(toId: string, chatType: ChatType, file: File, duration?: number): Promise<ImMessage> {
+  const result = await uploadFile(file)
+  const content = JSON.stringify({
+    url: result.url,
+    ...(duration !== undefined ? { duration } : {}),
+  })
+  return sendMessage({ toId, chatType, msgType: 'AUDIO', content })
+}
+
 export function createGroup(params: { name: string; memberIds: string[]; groupType?: string; avatar?: string; announcement?: string }): Promise<ImGroup> {
   return http.post<ImGroup>('/api/im/groups', params, appQuery())
 }
diff --git a/src/im/useIm.ts b/src/im/useIm.ts
index 862ac1a..3e7f17c 100644
--- a/src/im/useIm.ts
+++ b/src/im/useIm.ts
@@ -174,6 +174,9 @@ export function useIm(): UseImReturn {
       markMessageRevoked(msgId)
       void refreshConversations().catch(() => {})
     })
+    im.on('conversations', () => {
+      void refreshConversations().catch(() => {})
+    })
     im.on('error', (e) => { error.value = e })
     im.connect()
     client.value = im
diff --git a/src/index.ts b/src/index.ts
index 7a79124..6589f9c 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -41,6 +41,10 @@ export {
   sendFriendRequest,
   sendGroupJoinRequest,
   sendMessage,
+  sendImageMessage,
+  sendVideoMessage,
+  sendFileMessage,
+  sendAudioMessage,
   setConversationGroup,
   setConversationHidden,
   setConversationMuted,
diff --git a/src/types/index.ts b/src/types/index.ts
index 82567d8..cd77efb 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -1,6 +1,5 @@
 export interface SDKConfig {
   appKey: string
-  appSecret: string
   debug?: boolean
   baseUrl?: string
   wsUrl?: string
@@ -170,6 +169,7 @@ export interface ImEventMap {
   connected: () => void
   disconnected: (code: number, reason: string) => void
   error: (err: Event) => void
+  conversations: () => void
 }
 
 export interface ApiResponse<T> {