diff --git a/electron/main/database/sessionCache.ts b/electron/main/database/sessionCache.ts
index f44a2c62..24bc0bf6 100644
--- a/electron/main/database/sessionCache.ts
+++ b/electron/main/database/sessionCache.ts
@@ -1,187 +1,20 @@
 /**
- * 会话级通用 JSON 缓存模块
+ * Session cache — Electron re-export layer.
  *
- * 每个 session 对应一个 {sessionId}.cache.json，内部按 key 分区存储。
- * 与数据库 schema 完全解耦，读取失败自动重建，无需版本管理。
- *
- * 文件路径: {cacheDir}/{sessionId}.cache.json
+ * All logic has been extracted to @openchatlab/node-runtime/cache.
+ * This file provides backward-compatible imports for existing Electron code.
  */
 
-import * as fs from 'fs'
-import * as path from 'path'
-import type Database from 'better-sqlite3'
+export {
+  getCachePath,
+  getCache,
+  setCache,
+  invalidateCache,
+  deleteSessionCache,
+  computeAndSetOverviewCache,
+  computeAndSetMembersCache,
+  CACHE_KEY_OVERVIEW,
+  CACHE_KEY_MEMBERS,
+} from '@openchatlab/node-runtime'
 
-// ==================== 通用缓存基础设施 ====================
-
-interface CacheEntry<T = unknown> {
-  data: T
-  ts: number
-}
-
-type CacheFile = Record<string, CacheEntry>
-
-export function getCachePath(sessionId: string, cacheDir: string): string {
-  return path.join(cacheDir, `${sessionId}.cache.json`)
-}
-
-function readCacheFile(cachePath: string): CacheFile | null {
-  try {
-    if (!fs.existsSync(cachePath)) return null
-    return JSON.parse(fs.readFileSync(cachePath, 'utf-8')) as CacheFile
-  } catch {
-    return null
-  }
-}
-
-function writeCacheFile(cachePath: string, content: CacheFile): void {
-  try {
-    const dir = path.dirname(cachePath)
-    if (!fs.existsSync(dir)) {
-      fs.mkdirSync(dir, { recursive: true })
-    }
-    fs.writeFileSync(cachePath, JSON.stringify(content), 'utf-8')
-  } catch {
-    // 写入失败不影响主流程
-  }
-}
-
-/**
- * 读取缓存分区
- */
-export function getCache<T>(sessionId: string, key: string, cacheDir: string): T | null {
-  const cachePath = getCachePath(sessionId, cacheDir)
-  const file = readCacheFile(cachePath)
-  if (!file || !file[key]) return null
-  return file[key].data as T
-}
-
-/**
- * 写入缓存分区
- */
-export function setCache<T>(sessionId: string, key: string, data: T, cacheDir: string): void {
-  const cachePath = getCachePath(sessionId, cacheDir)
-  const file = readCacheFile(cachePath) ?? {}
-  file[key] = { data, ts: Math.floor(Date.now() / 1000) }
-  writeCacheFile(cachePath, file)
-}
-
-/**
- * 使缓存失效（不传 key 则清空整个文件）
- */
-export function invalidateCache(sessionId: string, cacheDir: string, key?: string): void {
-  const cachePath = getCachePath(sessionId, cacheDir)
-  try {
-    if (!key) {
-      if (fs.existsSync(cachePath)) fs.unlinkSync(cachePath)
-    } else {
-      const file = readCacheFile(cachePath)
-      if (file && file[key]) {
-        delete file[key]
-        writeCacheFile(cachePath, file)
-      }
-    }
-  } catch {
-    // 忽略失败
-  }
-}
-
-/**
- * 删除 session 的所有缓存
- */
-export function deleteSessionCache(sessionId: string, cacheDir: string): void {
-  const cachePath = getCachePath(sessionId, cacheDir)
-  try {
-    if (fs.existsSync(cachePath)) fs.unlinkSync(cachePath)
-  } catch {
-    // 忽略删除失败
-  }
-}
-
-// ==================== Overview 缓存（聚合统计） ====================
-
-export const CACHE_KEY_OVERVIEW = 'overview'
-
-export interface OverviewCache {
-  totalMessages: number
-  totalMembers: number
-  firstMessageTs: number | null
-  lastMessageTs: number | null
-}
-
-/**
- * 从数据库计算概览统计并写入缓存
- */
-export function computeAndSetOverviewCache(db: Database.Database, sessionId: string, cacheDir: string): OverviewCache {
-  const msgStats = db.prepare('SELECT MIN(ts) as first_ts, MAX(ts) as last_ts FROM message').get() as {
-    first_ts: number | null
-    last_ts: number | null
-  }
-
-  const totalMessages = (
-    db
-      .prepare(
-        `SELECT COUNT(*) as count FROM message msg
-         JOIN member m ON msg.sender_id = m.id
-         WHERE COALESCE(m.account_name, '') != '系统消息'`
-      )
-      .get() as { count: number }
-  ).count
-
-  const totalMembers = (
-    db.prepare(`SELECT COUNT(*) as count FROM member WHERE COALESCE(account_name, '') != '系统消息'`).get() as {
-      count: number
-    }
-  ).count
-
-  const data: OverviewCache = {
-    totalMessages,
-    totalMembers,
-    firstMessageTs: msgStats.first_ts,
-    lastMessageTs: msgStats.last_ts,
-  }
-
-  setCache(sessionId, CACHE_KEY_OVERVIEW, data, cacheDir)
-
-  // 同步生成成员缓存
-  computeAndSetMembersCache(db, sessionId, cacheDir)
-
-  return data
-}
-
-// ==================== Members 缓存（成员维度） ====================
-
-export const CACHE_KEY_MEMBERS = 'members'
-
-export interface MemberStat {
-  name: string
-  count: number
-}
-
-export interface MembersCache {
-  /** member.id -> { name, count } */
-  members: Record<number, MemberStat>
-}
-
-/**
- * 从数据库计算成员统计并写入缓存
- */
-export function computeAndSetMembersCache(db: Database.Database, sessionId: string, cacheDir: string): MembersCache {
-  const rows = db
-    .prepare(
-      `SELECT msg.sender_id, COUNT(*) as count,
-              COALESCE(m.group_nickname, m.account_name, m.platform_id) as name
-       FROM message msg
-       JOIN member m ON msg.sender_id = m.id
-       GROUP BY msg.sender_id`
-    )
-    .all() as Array<{ sender_id: number; count: number; name: string }>
-
-  const members: Record<number, MemberStat> = {}
-  for (const row of rows) {
-    members[row.sender_id] = { name: row.name, count: row.count }
-  }
-
-  const data: MembersCache = { members }
-  setCache(sessionId, CACHE_KEY_MEMBERS, data, cacheDir)
-  return data
-}
+export type { OverviewCache, MembersCache, MemberStat } from '@openchatlab/node-runtime'
diff --git a/electron/main/worker/import/incrementalImport.ts b/electron/main/worker/import/incrementalImport.ts
index dbea25bc..e2547098 100644
--- a/electron/main/worker/import/incrementalImport.ts
+++ b/electron/main/worker/import/incrementalImport.ts
@@ -44,7 +44,7 @@ function buildDeps(requestId: string): IncrementalImportDeps {
         const { computeAndSetOverviewCache } = await import('../../database/sessionCache')
         const dbPath = getDbPath(sessionId)
         const rawDb = new Database(dbPath)
-        computeAndSetOverviewCache(rawDb, sessionId, getCacheDir())
+        computeAndSetOverviewCache(new BetterSqliteAdapter(rawDb), sessionId, getCacheDir())
         rawDb.close()
       } catch {
         /* non-fatal */
diff --git a/electron/main/worker/import/streamImport.ts b/electron/main/worker/import/streamImport.ts
index 3f5dd049..93533612 100644
--- a/electron/main/worker/import/streamImport.ts
+++ b/electron/main/worker/import/streamImport.ts
@@ -72,7 +72,7 @@ function buildStreamImportDeps(requestId: string): StreamImportDeps {
         const { computeAndSetOverviewCache } = await import('../../database/sessionCache')
         const dbPath = getDbPath(sessionId)
         const rawDb = new Database(dbPath)
-        computeAndSetOverviewCache(rawDb, sessionId, getCacheDir())
+        computeAndSetOverviewCache(new BetterSqliteAdapter(rawDb), sessionId, getCacheDir())
         rawDb.close()
       } catch {
         /* non-fatal */
diff --git a/electron/main/worker/query/sessions.ts b/electron/main/worker/query/sessions.ts
index ea08b59c..e6ab7814 100644
--- a/electron/main/worker/query/sessions.ts
+++ b/electron/main/worker/query/sessions.ts
@@ -8,6 +8,7 @@
  */
 
 import Database from 'better-sqlite3'
+import { BetterSqliteAdapter } from '@openchatlab/node-runtime'
 import * as fs from 'fs'
 import * as path from 'path'
 import { openDatabase, getDbDir, getDbPath, getCacheDir } from '../core'
@@ -89,7 +90,7 @@ function resolveOverview(db: Database.Database, sessionId: string, cacheDir: str
   let cached = cacheDir ? getCache<OverviewCache>(sessionId, CACHE_KEY_OVERVIEW, cacheDir) : null
   if (!cached && cacheDir) {
     try {
-      cached = computeAndSetOverviewCache(db, sessionId, cacheDir)
+      cached = computeAndSetOverviewCache(new BetterSqliteAdapter(db), sessionId, cacheDir)
     } catch {
       // cache compute failure — fall through to live query
     }
@@ -197,7 +198,7 @@ export function getChatOverview(sessionId: string, topN: number = 10) {
   let membersCache = getCache<MembersCache>(sessionId, CACHE_KEY_MEMBERS, cacheDir)
   if (!membersCache) {
     try {
-      membersCache = computeAndSetMembersCache(db, sessionId, cacheDir)
+      membersCache = computeAndSetMembersCache(new BetterSqliteAdapter(db), sessionId, cacheDir)
     } catch {
       // fallback: no member data
     }
diff --git a/packages/node-runtime/src/cache/index.ts b/packages/node-runtime/src/cache/index.ts
new file mode 100644
index 00000000..99952267
--- /dev/null
+++ b/packages/node-runtime/src/cache/index.ts
@@ -0,0 +1,12 @@
+export {
+  getCachePath,
+  getCache,
+  setCache,
+  invalidateCache,
+  deleteSessionCache,
+  computeAndSetOverviewCache,
+  computeAndSetMembersCache,
+  CACHE_KEY_OVERVIEW,
+  CACHE_KEY_MEMBERS,
+} from './session-cache'
+export type { OverviewCache, MembersCache, MemberStat } from './session-cache'
diff --git a/packages/node-runtime/src/cache/session-cache.ts b/packages/node-runtime/src/cache/session-cache.ts
new file mode 100644
index 00000000..14343793
--- /dev/null
+++ b/packages/node-runtime/src/cache/session-cache.ts
@@ -0,0 +1,167 @@
+/**
+ * Session-level JSON cache module (platform-agnostic).
+ *
+ * Extracted from electron/main/database/sessionCache.ts.
+ * Each session has a {sessionId}.cache.json file partitioned by key.
+ * Decoupled from DB schema — reads auto-rebuild on failure, no versioning needed.
+ *
+ * File path: {cacheDir}/{sessionId}.cache.json
+ */
+
+import * as fs from 'fs'
+import * as path from 'path'
+import type { DatabaseAdapter } from '@openchatlab/core'
+
+// ==================== Generic cache infrastructure ====================
+
+interface CacheEntry<T = unknown> {
+  data: T
+  ts: number
+}
+
+type CacheFile = Record<string, CacheEntry>
+
+export function getCachePath(sessionId: string, cacheDir: string): string {
+  return path.join(cacheDir, `${sessionId}.cache.json`)
+}
+
+function readCacheFile(cachePath: string): CacheFile | null {
+  try {
+    if (!fs.existsSync(cachePath)) return null
+    return JSON.parse(fs.readFileSync(cachePath, 'utf-8')) as CacheFile
+  } catch {
+    return null
+  }
+}
+
+function writeCacheFile(cachePath: string, content: CacheFile): void {
+  try {
+    const dir = path.dirname(cachePath)
+    if (!fs.existsSync(dir)) {
+      fs.mkdirSync(dir, { recursive: true })
+    }
+    fs.writeFileSync(cachePath, JSON.stringify(content), 'utf-8')
+  } catch {
+    // Write failure is non-fatal
+  }
+}
+
+export function getCache<T>(sessionId: string, key: string, cacheDir: string): T | null {
+  const cachePath = getCachePath(sessionId, cacheDir)
+  const file = readCacheFile(cachePath)
+  if (!file || !file[key]) return null
+  return file[key].data as T
+}
+
+export function setCache<T>(sessionId: string, key: string, data: T, cacheDir: string): void {
+  const cachePath = getCachePath(sessionId, cacheDir)
+  const file = readCacheFile(cachePath) ?? {}
+  file[key] = { data, ts: Math.floor(Date.now() / 1000) }
+  writeCacheFile(cachePath, file)
+}
+
+export function invalidateCache(sessionId: string, cacheDir: string, key?: string): void {
+  const cachePath = getCachePath(sessionId, cacheDir)
+  try {
+    if (!key) {
+      if (fs.existsSync(cachePath)) fs.unlinkSync(cachePath)
+    } else {
+      const file = readCacheFile(cachePath)
+      if (file && file[key]) {
+        delete file[key]
+        writeCacheFile(cachePath, file)
+      }
+    }
+  } catch {
+    // Ignore
+  }
+}
+
+export function deleteSessionCache(sessionId: string, cacheDir: string): void {
+  const cachePath = getCachePath(sessionId, cacheDir)
+  try {
+    if (fs.existsSync(cachePath)) fs.unlinkSync(cachePath)
+  } catch {
+    // Ignore
+  }
+}
+
+// ==================== Overview cache (aggregate stats) ====================
+
+export const CACHE_KEY_OVERVIEW = 'overview'
+
+export interface OverviewCache {
+  totalMessages: number
+  totalMembers: number
+  firstMessageTs: number | null
+  lastMessageTs: number | null
+}
+
+export function computeAndSetOverviewCache(db: DatabaseAdapter, sessionId: string, cacheDir: string): OverviewCache {
+  const msgStats = db.prepare('SELECT MIN(ts) as first_ts, MAX(ts) as last_ts FROM message').get() as {
+    first_ts: number | null
+    last_ts: number | null
+  }
+
+  const totalMessages = (
+    db
+      .prepare(
+        `SELECT COUNT(*) as count FROM message msg
+         JOIN member m ON msg.sender_id = m.id
+         WHERE COALESCE(m.account_name, '') != '系统消息'`
+      )
+      .get() as { count: number }
+  ).count
+
+  const totalMembers = (
+    db.prepare(`SELECT COUNT(*) as count FROM member WHERE COALESCE(account_name, '') != '系统消息'`).get() as {
+      count: number
+    }
+  ).count
+
+  const data: OverviewCache = {
+    totalMessages,
+    totalMembers,
+    firstMessageTs: msgStats.first_ts,
+    lastMessageTs: msgStats.last_ts,
+  }
+
+  setCache(sessionId, CACHE_KEY_OVERVIEW, data, cacheDir)
+  computeAndSetMembersCache(db, sessionId, cacheDir)
+
+  return data
+}
+
+// ==================== Members cache (per-member stats) ====================
+
+export const CACHE_KEY_MEMBERS = 'members'
+
+export interface MemberStat {
+  name: string
+  count: number
+}
+
+export interface MembersCache {
+  members: Record<number, MemberStat>
+}
+
+export function computeAndSetMembersCache(db: DatabaseAdapter, sessionId: string, cacheDir: string): MembersCache {
+  const rows = db
+    .prepare(
+      `SELECT msg.sender_id, COUNT(*) as count,
+              COALESCE(m.group_nickname, m.account_name, m.platform_id) as name
+       FROM message msg
+       JOIN member m ON msg.sender_id = m.id
+       GROUP BY msg.sender_id`
+    )
+    .all() as Array<{ sender_id: number; count: number; name: string }>
+
+  const members: Record<number, MemberStat> = {}
+  for (const row of rows) {
+    members[row.sender_id] = { name: row.name, count: row.count }
+  }
+
+  const data: MembersCache = { members }
+  setCache(sessionId, CACHE_KEY_MEMBERS, data, cacheDir)
+  return data
+}
diff --git a/packages/node-runtime/src/index.ts b/packages/node-runtime/src/index.ts
index 3263fd59..00f5153c 100644
--- a/packages/node-runtime/src/index.ts
+++ b/packages/node-runtime/src/index.ts
@@ -188,6 +188,20 @@ export type { PiModelConfig, BuildPiModelOptions } from './ai'
 export { fetchRemoteModels, validateApiKey } from './ai'
 export type { RemoteModel, FetchRemoteModelsResult, RemoteApiOptions } from './ai'
 
+// Session cache (overview + members JSON file cache)
+export {
+  getCachePath,
+  getCache,
+  setCache,
+  invalidateCache,
+  deleteSessionCache,
+  computeAndSetOverviewCache,
+  computeAndSetMembersCache,
+  CACHE_KEY_OVERVIEW,
+  CACHE_KEY_MEMBERS,
+} from './cache'
+export type { OverviewCache, MembersCache, MemberStat } from './cache'
+
 // Chat DB migrations
 export { getChatDbMigrations } from './migrations'
 export type { MigrationDeps } from './migrations'