diff --git a/apps/backend/src/services/session/session-activity.js b/apps/backend/src/services/session/session-activity.ts
similarity index 68%
rename from apps/backend/src/services/session/session-activity.js
rename to apps/backend/src/services/session/session-activity.ts
index 5572f6fa..5010cf5a 100644
--- a/apps/backend/src/services/session/session-activity.js
+++ b/apps/backend/src/services/session/session-activity.ts
@@ -1,9 +1,83 @@
-// @ts-nocheck
+/// <reference lib="dom" />
 
 import { extractHostState, reloadActivityPageForPresentation } from './session-page.js'
 import { shouldRefreshLoggedInPresentation } from './session-state.js'
 
-export function createEmptyActivityInfo() {
+type BrowserPageLike = {
+  evaluate: <T = any>(callback: any) => Promise<T>
+  waitForTimeout: (milliseconds: number) => Promise<void>
+}
+
+type HostState = {
+  loginText?: string
+  unloginVisible?: boolean
+  loginedVisible?: boolean
+}
+
+export type ActivityInfo = {
+  nickname: string
+  role: {
+    ready: boolean
+    roleName: string
+    roleId: string
+    area: string
+    partition: string
+    platId: string
+    md5str: string
+    checkparam: string
+  }
+  form: {
+    cdkeyInputId: string
+    cdkeyValue: string
+    verifyInputId: string
+    verifyValue: string
+    verifyImgId: string
+    submitId: string
+  }
+  verify: {
+    visible: boolean
+    src: string
+    naturalWidth: number
+    naturalHeight: number
+  }
+  popup: {
+    visible: boolean
+    text: string
+    detail: string
+  }
+}
+
+type SessionForPresentation = {
+  page: BrowserPageLike
+  presentationSyncAttempts: number
+}
+
+type EnsureLoggedInPresentationOptions = {
+  hostState?: HostState | null
+  credentialReady?: boolean
+  activityUrl?: string
+  extractHostState?: (page: BrowserPageLike) => Promise<HostState>
+  reloadActivityPageForPresentation?: (page: BrowserPageLike, activityUrl: string) => Promise<unknown>
+  shouldRefreshLoggedInPresentation?: (hostState: HostState) => boolean
+}
+
+type EnsureActivityInfoReadyOptions = {
+  triggerRender?: boolean
+  timeoutMs?: number
+  extractActivityInfo?: (page: BrowserPageLike) => Promise<ActivityInfo>
+  triggerActivityRoleRender?: (page: BrowserPageLike) => Promise<unknown>
+  now?: () => number
+}
+
+declare global {
+  interface Window {
+    renderCdkey?: () => void
+    roleData?: Record<string, unknown>
+    isRole?: unknown
+  }
+}
+
+export function createEmptyActivityInfo(): ActivityInfo {
   return {
     nickname: '',
     role: {
@@ -39,7 +113,7 @@ export function createEmptyActivityInfo() {
 }
 
 export async function ensureLoggedInPresentation(
-  session,
+  session: SessionForPresentation,
   {
     hostState = null,
     credentialReady = false,
@@ -47,8 +121,8 @@ export async function ensureLoggedInPresentation(
     extractHostState: extractHostStateImpl = extractHostState,
     reloadActivityPageForPresentation: reloadActivityPageForPresentationImpl = reloadActivityPageForPresentation,
     shouldRefreshLoggedInPresentation: shouldRefreshLoggedInPresentationImpl = shouldRefreshLoggedInPresentation,
-  } = {},
-) {
+  }: EnsureLoggedInPresentationOptions = {},
+): Promise<{ reloaded: boolean; hostState: HostState }> {
   let nextHostState = hostState || (await extractHostStateImpl(session.page))
 
   if (!credentialReady || !shouldRefreshLoggedInPresentationImpl(nextHostState)) {
@@ -76,15 +150,15 @@ export async function ensureLoggedInPresentation(
 }
 
 export async function ensureActivityInfoReady(
-  page,
+  page: BrowserPageLike,
   {
     triggerRender = false,
     timeoutMs = 8_000,
     extractActivityInfo: extractActivityInfoImpl = extractActivityInfo,
     triggerActivityRoleRender: triggerActivityRoleRenderImpl = triggerActivityRoleRender,
     now = () => Date.now(),
-  } = {},
-) {
+  }: EnsureActivityInfoReadyOptions = {},
+): Promise<ActivityInfo> {
   if (triggerRender) {
     await triggerActivityRoleRenderImpl(page)
   }
@@ -104,7 +178,7 @@ export async function ensureActivityInfoReady(
   return lastInfo
 }
 
-export async function triggerActivityRoleRender(page) {
+export async function triggerActivityRoleRender(page: BrowserPageLike): Promise<void> {
   try {
     await page.evaluate(() => {
       const maybeRender = window.renderCdkey
@@ -118,11 +192,11 @@ export async function triggerActivityRoleRender(page) {
   }
 }
 
-export async function extractActivityInfo(page) {
+export async function extractActivityInfo(page: BrowserPageLike): Promise<ActivityInfo> {
   try {
     return await page.evaluate(() => {
-      const asString = (value) => (typeof value === 'string' ? value.trim() : '')
-      const isVisible = (element) => {
+      const asString = (value: unknown) => (typeof value === 'string' ? value.trim() : '')
+      const isVisible = (element: Element | null) => {
         if (!element) {
           return false
         }
@@ -131,8 +205,11 @@ export async function extractActivityInfo(page) {
         return style.display !== 'none' && style.visibility !== 'hidden' && style.opacity !== '0'
       }
 
-      const pick = (selector) => document.querySelector(selector)
-      const pickBest = (selector, predicate = null) => {
+      const pick = (selector: string) => document.querySelector(selector)
+      const pickBest = (
+        selector: string,
+        predicate: ((element: Element) => boolean) | null = null,
+      ): Element | null => {
         const matches = [...document.querySelectorAll(selector)]
         const preferred = matches.find((element) => {
           if (predicate && !predicate(element)) {
@@ -170,7 +247,7 @@ export async function extractActivityInfo(page) {
       const roleSelector = pick('[id^="milo_role_selector_"]')
       const roleNameText =
         textOf('#role_name') ||
-        asString(roleSelector?.selectedOptions?.[0]?.textContent || '')
+        asString(roleSelector instanceof HTMLSelectElement ? roleSelector.selectedOptions?.[0]?.textContent || '' : '')
       const verifyImg = pickBest('[id^="milo_verifyImg_"]', (node) => node instanceof HTMLImageElement)
       const popup = pick('#pop2')
       const cdkeyInput = pickBest(
@@ -215,8 +292,8 @@ export async function extractActivityInfo(page) {
         verify: {
           visible: isVisible(verifyImg),
           src: asString(verifyImg?.getAttribute('src')),
-          naturalWidth: Number(verifyImg?.naturalWidth || 0),
-          naturalHeight: Number(verifyImg?.naturalHeight || 0),
+          naturalWidth: verifyImg instanceof HTMLImageElement ? Number(verifyImg.naturalWidth || 0) : 0,
+          naturalHeight: verifyImg instanceof HTMLImageElement ? Number(verifyImg.naturalHeight || 0) : 0,
         },
         popup: {
           visible: isVisible(popup),
diff --git a/docs/backend-typescript-migration-plan.md b/docs/backend-typescript-migration-plan.md
index 0caa7fe7..08930aea 100644
--- a/docs/backend-typescript-migration-plan.md
+++ b/docs/backend-typescript-migration-plan.md
@@ -488,6 +488,14 @@
     - `npm run typecheck`
     - `npm run build`
     - `npm test` 共 139 个用例通过
+104. 腾讯浏览器会话 activity 信息模块迁移到 `.ts`：
+    - `src/services/session/session-activity.ts`
+105. 活动角色 / 表单 / 验证码 / 弹窗信息结构、登录态 presentation 同步、角色渲染触发与轮询已显式类型化
+106. Docker 内验证通过：
+    - `src/services/session/session.test.js` 共 14 个用例通过
+    - `npm run typecheck`
+    - `npm run build`
+    - `npm test` 共 139 个用例通过
 
 ## 下一步建议