diff --git a/apps/backend/src/services/claim/session/redeem.js b/apps/backend/src/services/claim/session/redeem.ts
similarity index 66%
rename from apps/backend/src/services/claim/session/redeem.js
rename to apps/backend/src/services/claim/session/redeem.ts
index 96130b72..cb50ecc2 100644
--- a/apps/backend/src/services/claim/session/redeem.js
+++ b/apps/backend/src/services/claim/session/redeem.ts
@@ -1,5 +1,3 @@
-// @ts-check
-
 import { reloadTencentBrowserSession, redeemTencentBrowserSession } from '../../session/session.js'
 import { classifyTencentRedeemResult } from '../../session/session-redeem.js'
 import { createTaskEvent } from '../../../repositories/task-event-repo.js'
@@ -11,14 +9,127 @@ import { reserveInventoryForTask } from '../../order/inventory-service.js'
 import { createHttpError } from '../../../utils/http.js'
 import { nowIso } from '../../../utils/time.js'
 import { maskCode, REDEEM_REPLACEMENT_LIMIT } from './shared.js'
+import type { InventoryItemRow, OrderItemRow, TaskRow } from '../../../types/repository-rows.js'
 
-export async function redeemClaimTaskWithInventoryFallback(context, initialInventoryItem) {
+type ClaimRedeemContext = {
+  task: Pick<TaskRow, 'id' | 'browser_session_id'>
+  orderItem: Pick<OrderItemRow, 'sku_code'>
+}
+
+type TencentRedeemPayload = {
+  [key: string]: unknown
+  iRet?: unknown
+  ret?: unknown
+}
+
+type TencentRedeemSession = {
+  [key: string]: unknown
+  sessionId?: string
+  artifacts?: {
+    [key: string]: unknown
+    hasScreenshot?: boolean
+  } | null
+  redeem?: {
+    final?: {
+      redeem?: TencentRedeemPayload | null
+    } | null
+  } | null
+}
+
+type TencentRedeemClassification = {
+  success: boolean
+  outcome: string
+  message: string
+  retCode?: unknown
+  [key: string]: unknown
+}
+
+type RedeemAttemptSummary = {
+  attempt: number
+  inventoryItemId: number
+  codeMasked: string
+  credentialType: string
+  outcome: string
+  resultCode: string
+  resultMessage: string
+}
+
+type RedeemTaskState = {
+  taskStatus: string
+  inventoryStatus: string
+  deliveryStatus: string
+  lastError: string
+  attempts: RedeemAttemptSummary[]
+  classification: TencentRedeemClassification | null
+}
+
+type RedeemTaskStateError = Error & {
+  statusCode?: number
+  errorCode?: string
+  redeemTaskState: RedeemTaskState
+}
+
+type RedeemTaskStateErrorPayload = {
+  statusCode?: number
+  errorCode?: string
+  taskStatus?: string
+  inventoryStatus?: string
+  deliveryStatus?: string
+  attempts?: RedeemAttemptSummary[]
+  classification?: TencentRedeemClassification | null
+}
+
+type RedeemClaimTaskDeps = {
+  reloadTencentBrowserSession?: (sessionId: string) => Promise<unknown>
+  redeemTencentBrowserSession?: (
+    sessionId: string,
+    payload: { code: string },
+  ) => Promise<TencentRedeemSession>
+  classifyTencentRedeemResult?: (finalRedeem: TencentRedeemPayload | null) => TencentRedeemClassification
+  markInventoryItemConsumed?: (
+    inventoryItemId: number | string,
+    reason: string,
+    consumedAt: string,
+  ) => Promise<InventoryItemRow | null>
+  createTaskEvent?: (
+    taskId: number | string,
+    eventType: string,
+    payload?: unknown,
+    createdAt?: string,
+  ) => Promise<unknown>
+  invalidateReservedInventoryItem?: (
+    inventoryItemId: number | string,
+    reason: string,
+    updatedAt: string,
+  ) => Promise<InventoryItemRow | null>
+  reserveInventoryForTask?: (payload: {
+    skuCode: string
+    taskId: number | string
+    credentialType?: string
+    roleKey?: string
+    inventoryGroupCodes?: string[] | null
+  }) => Promise<InventoryItemRow | null>
+  nowIso?: () => string
+  redeemReplacementLimit?: number
+}
+
+type RedeemClaimTaskResult = {
+  session: TencentRedeemSession
+  inventoryItem: InventoryItemRow
+  classification: TencentRedeemClassification
+  attempts: RedeemAttemptSummary[]
+}
+
+export async function redeemClaimTaskWithInventoryFallback(
+  context: ClaimRedeemContext,
+  initialInventoryItem: InventoryItemRow,
+): Promise<RedeemClaimTaskResult> {
   return redeemClaimTaskWithInventoryFallbackWithDeps(context, initialInventoryItem)
 }
 
 export async function redeemClaimTaskWithInventoryFallbackWithDeps(
-  context,
-  initialInventoryItem,
+  context: ClaimRedeemContext,
+  initialInventoryItem: InventoryItemRow,
   {
     reloadTencentBrowserSession: reloadRedeemSession = reloadTencentBrowserSession,
     redeemTencentBrowserSession: redeemSession = redeemTencentBrowserSession,
@@ -29,9 +140,9 @@ export async function redeemClaimTaskWithInventoryFallbackWithDeps(
     reserveInventoryForTask: reserveReplacementInventory = reserveInventoryForTask,
     nowIso: getNowIso = nowIso,
     redeemReplacementLimit = REDEEM_REPLACEMENT_LIMIT,
-  } = {},
-) {
-  const attempts = []
+  }: RedeemClaimTaskDeps = {},
+): Promise<RedeemClaimTaskResult> {
+  const attempts: RedeemAttemptSummary[] = []
   let currentInventoryItem = initialInventoryItem
   let shouldReloadBeforeNextAttempt = false
 
@@ -156,15 +267,14 @@ export async function redeemClaimTaskWithInventoryFallbackWithDeps(
   })
 }
 
-/**
- * @param {string} message
- * @param {{ statusCode?: number, errorCode?: string, taskStatus?: string, inventoryStatus?: string, deliveryStatus?: string, attempts?: unknown[], classification?: { retCode?: unknown } | null }} [payload]
- */
-function createRedeemTaskStateError(message, payload = {}) {
-  const error = /** @type {Error & import('../../../utils/http.js').HttpErrorLike & { redeemTaskState: { taskStatus: string, inventoryStatus: string, deliveryStatus: string, lastError: string, attempts: unknown[], classification: { retCode?: unknown } | null } }} */ (createHttpError(message, {
+function createRedeemTaskStateError(
+  message: string,
+  payload: RedeemTaskStateErrorPayload = {},
+): RedeemTaskStateError {
+  const error = createHttpError(message, {
     statusCode: payload.statusCode || 409,
     errorCode: payload.errorCode || 'claim_redeem_failed',
-  }))
+  }) as unknown as RedeemTaskStateError
 
   error.redeemTaskState = {
     taskStatus: payload.taskStatus || 'retry_pending',
@@ -178,7 +288,10 @@ function createRedeemTaskStateError(message, payload = {}) {
   return error
 }
 
-export function resolveTencentRedeemResultCode(finalRedeem, classification) {
+export function resolveTencentRedeemResultCode(
+  finalRedeem: TencentRedeemPayload | null,
+  classification: Pick<TencentRedeemClassification, 'retCode'> | null,
+): string {
   if (classification?.retCode != null) {
     return String(classification.retCode)
   }
diff --git a/docs/backend-typescript-migration-plan.md b/docs/backend-typescript-migration-plan.md
index 153c8f96..a654fb59 100644
--- a/docs/backend-typescript-migration-plan.md
+++ b/docs/backend-typescript-migration-plan.md
@@ -264,13 +264,21 @@
     - `npm run typecheck`
     - `npm run build`
     - `npm test` 共 125 个用例通过
+28. claim 换码服务迁移到 `.ts`：
+    - `src/services/claim/session/redeem.ts`
+29. 换码流程的上下文、腾讯兑换返回、分类结果、尝试记录、错误状态、依赖注入函数已显式类型化
+30. Docker 内验证通过：
+    - claim 换码相关 2 个测试文件共 8 个用例通过
+    - `npm run typecheck`
+    - `npm run build`
+    - `npm test` 共 125 个用例通过
 
 ## 下一步建议
 
 第一批继续推进时，建议按这个顺序：
 
 1. 继续迁移服务层中最核心、最常改的订单 / 履约 / claim 模块
-2. 逐步移除服务层 `@ts-nocheck`，优先处理 claim session、webhook service、自动发货
+2. 逐步移除服务层 `@ts-nocheck`，优先处理 webhook service、自动发货
 
 ## 执行原则