diff --git a/electron/main/ai/tools/registry.ts b/electron/main/ai/tools/registry.ts
index e76497e..1742525 100644
--- a/electron/main/ai/tools/registry.ts
+++ b/electron/main/ai/tools/registry.ts
@@ -751,6 +751,171 @@ async function getMessageContextExecutor(
   }
 }
 
+// ==================== 会话相关工具 ====================
+
+/**
+ * 搜索会话工具
+ * 根据关键词和时间范围搜索会话
+ */
+const searchSessionsTool: ToolDefinition = {
+  type: 'function',
+  function: {
+    name: 'search_sessions',
+    description:
+      '搜索聊天会话（对话段落）。会话是根据消息时间间隔自动切分的对话单元。适用于查找特定话题的讨论、了解某个时间段内发生了几次对话等场景。返回匹配的会话列表及每个会话的前5条消息预览。',
+    parameters: {
+      type: 'object',
+      properties: {
+        keywords: {
+          type: 'array',
+          description: '可选的搜索关键词列表，只返回包含这些关键词的会话（OR 逻辑匹配）',
+          items: { type: 'string' },
+        },
+        limit: {
+          type: 'number',
+          description: '返回会话数量限制，默认 20',
+        },
+        year: {
+          type: 'number',
+          description: '筛选指定年份的会话，如 2024',
+        },
+        month: {
+          type: 'number',
+          description: '筛选指定月份的会话（1-12），需要配合 year 使用',
+        },
+        day: {
+          type: 'number',
+          description: '筛选指定日期的会话（1-31），需要配合 year 和 month 使用',
+        },
+        start_time: {
+          type: 'string',
+          description: '开始时间，格式 "YYYY-MM-DD HH:mm"，如 "2024-03-15 14:00"',
+        },
+        end_time: {
+          type: 'string',
+          description: '结束时间，格式 "YYYY-MM-DD HH:mm"，如 "2024-03-15 18:30"',
+        },
+      },
+    },
+  },
+}
+
+async function searchSessionsExecutor(
+  params: {
+    keywords?: string[]
+    limit?: number
+    year?: number
+    month?: number
+    day?: number
+    start_time?: string
+    end_time?: string
+  },
+  context: ToolContext
+): Promise<unknown> {
+  const { sessionId, timeFilter: contextTimeFilter, locale } = context
+  const limit = params.limit || 20
+
+  // 使用扩展的时间参数解析
+  const effectiveTimeFilter = parseExtendedTimeParams(params, contextTimeFilter)
+
+  const sessions = await workerManager.searchSessions(
+    sessionId,
+    params.keywords,
+    effectiveTimeFilter,
+    limit,
+    5 // 预览5条消息
+  )
+
+  if (sessions.length === 0) {
+    return {
+      total: 0,
+      message: isChineseLocale(locale) ? '未找到匹配的会话' : 'No matching sessions found',
+    }
+  }
+
+  const localeStr = isChineseLocale(locale) ? 'zh-CN' : 'en-US'
+  const msgSuffix = isChineseLocale(locale) ? '条消息' : ' messages'
+  const completeLabel = isChineseLocale(locale) ? '完整会话' : 'complete'
+
+  return {
+    total: sessions.length,
+    timeRange: formatTimeRange(effectiveTimeFilter, locale),
+    sessions: sessions.map((s) => {
+      const startTime = new Date(s.startTs * 1000).toLocaleString(localeStr)
+      const endTime = new Date(s.endTs * 1000).toLocaleString(localeStr)
+      const completeTag = s.isComplete ? ` [${completeLabel}]` : ''
+
+      return {
+        sessionId: s.id,
+        time: `${startTime} ~ ${endTime}`,
+        messageCount: `${s.messageCount}${msgSuffix}${completeTag}`,
+        preview: s.previewMessages.map((m) => formatMessageCompact(m, locale)),
+      }
+    }),
+  }
+}
+
+/**
+ * 获取会话消息工具
+ * 获取指定会话的完整消息列表
+ */
+const getSessionMessagesTool: ToolDefinition = {
+  type: 'function',
+  function: {
+    name: 'get_session_messages',
+    description:
+      '获取指定会话的完整消息列表。用于在 search_sessions 找到相关会话后，获取该会话的完整上下文。返回会话的所有消息及参与者信息。',
+    parameters: {
+      type: 'object',
+      properties: {
+        session_id: {
+          type: 'number',
+          description: '会话 ID，可以从 search_sessions 的返回结果中获取',
+        },
+        limit: {
+          type: 'number',
+          description: '返回消息数量限制，默认 500。对于超长会话可以限制返回数量以节省 token',
+        },
+      },
+      required: ['session_id'],
+    },
+  },
+}
+
+async function getSessionMessagesExecutor(
+  params: {
+    session_id: number
+    limit?: number
+  },
+  context: ToolContext
+): Promise<unknown> {
+  const { sessionId, maxMessagesLimit, locale } = context
+  // 用户配置优先
+  const limit = maxMessagesLimit || params.limit || 500
+
+  const result = await workerManager.getSessionMessages(sessionId, params.session_id, limit)
+
+  if (!result) {
+    return {
+      error: isChineseLocale(locale) ? '未找到指定的会话' : 'Session not found',
+      sessionId: params.session_id,
+    }
+  }
+
+  const localeStr = isChineseLocale(locale) ? 'zh-CN' : 'en-US'
+  const startTime = new Date(result.startTs * 1000).toLocaleString(localeStr)
+  const endTime = new Date(result.endTs * 1000).toLocaleString(localeStr)
+
+  return {
+    sessionId: result.sessionId,
+    time: `${startTime} ~ ${endTime}`,
+    messageCount: result.messageCount,
+    returnedCount: result.returnedCount,
+    participants: result.participants,
+    messages: result.messages.map((m) => formatMessageCompact(m, locale)),
+  }
+}
+
 // ==================== 注册工具 ====================
 
 registerTool(searchMessagesTool, searchMessagesExecutor)
@@ -761,3 +926,5 @@ registerTool(getGroupMembersTool, getGroupMembersExecutor)
 registerTool(getMemberNameHistoryTool, getMemberNameHistoryExecutor)
 registerTool(getConversationBetweenTool, getConversationBetweenExecutor)
 registerTool(getMessageContextTool, getMessageContextExecutor)
+registerTool(searchSessionsTool, searchSessionsExecutor)
+registerTool(getSessionMessagesTool, getSessionMessagesExecutor)
diff --git a/electron/main/worker/dbWorker.ts b/electron/main/worker/dbWorker.ts
index 1858709..0815239 100644
--- a/electron/main/worker/dbWorker.ts
+++ b/electron/main/worker/dbWorker.ts
@@ -54,6 +54,8 @@ import {
   getSessionStats,
   updateSessionGapThreshold,
   getSessions,
+  searchSessions,
+  getSessionMessages,
 } from './query'
 import { streamImport, streamParseFileInfo } from './import'
 
@@ -130,6 +132,8 @@ const syncHandlers: Record<string, (payload: any) => any> = {
   getSessionStats: (p) => getSessionStats(p.sessionId),
   updateSessionGapThreshold: (p) => updateSessionGapThreshold(p.sessionId, p.gapThreshold),
   getSessions: (p) => getSessions(p.sessionId),
+  searchSessions: (p) => searchSessions(p.sessionId, p.keywords, p.timeFilter, p.limit, p.previewCount),
+  getSessionMessages: (p) => getSessionMessages(p.sessionId, p.chatSessionId, p.limit),
 }
 
 // 异步消息处理器（流式操作）
diff --git a/electron/main/worker/query/index.ts b/electron/main/worker/query/index.ts
index 6c6582b..a86c826 100644
--- a/electron/main/worker/query/index.ts
+++ b/electron/main/worker/query/index.ts
@@ -62,6 +62,8 @@ export {
   getSessionStats,
   updateSessionGapThreshold,
   getSessions,
+  searchSessions,
+  getSessionMessages,
   DEFAULT_SESSION_GAP_THRESHOLD,
 } from './session'
-export type { ChatSessionItem } from './session'
+export type { ChatSessionItem, SessionSearchResultItem, SessionMessagesResult } from './session'
diff --git a/electron/main/worker/query/session.ts b/electron/main/worker/query/session.ts
index 7a0b6f0..50d7ea0 100644
--- a/electron/main/worker/query/session.ts
+++ b/electron/main/worker/query/session.ts
@@ -340,3 +340,241 @@ export function getSessions(sessionId: string): ChatSessionItem[] {
     db.close()
   }
 }
+
+// ==================== AI 工具专用查询函数 ====================
+
+/**
+ * 会话搜索结果项类型（用于 AI 工具）
+ */
+export interface SessionSearchResultItem {
+  id: number
+  startTs: number
+  endTs: number
+  messageCount: number
+  /** 是否为完整会话（消息数 <= 预览条数） */
+  isComplete: boolean
+  /** 预览消息列表 */
+  previewMessages: Array<{
+    id: number
+    senderName: string
+    content: string | null
+    timestamp: number
+  }>
+}
+
+/**
+ * 搜索会话（用于 AI 工具）
+ * 支持按关键词和时间范围筛选会话
+ *
+ * @param sessionId 数据库会话ID
+ * @param keywords 关键词列表（可选，OR 逻辑匹配）
+ * @param timeFilter 时间过滤器（可选）
+ * @param limit 返回数量限制，默认 20
+ * @param previewCount 预览消息数量，默认 5
+ * @returns 匹配的会话列表
+ */
+export function searchSessions(
+  sessionId: string,
+  keywords?: string[],
+  timeFilter?: { startTs: number; endTs: number },
+  limit: number = 20,
+  previewCount: number = 5
+): SessionSearchResultItem[] {
+  const db = openReadonlyDatabase(sessionId)
+  if (!db) {
+    return []
+  }
+
+  try {
+    // 1. 构建会话查询 SQL
+    let sessionSql = `
+      SELECT
+        cs.id,
+        cs.start_ts as startTs,
+        cs.end_ts as endTs,
+        cs.message_count as messageCount
+      FROM chat_session cs
+      WHERE 1=1
+    `
+    const params: unknown[] = []
+
+    // 时间范围过滤
+    if (timeFilter) {
+      sessionSql += ` AND cs.start_ts >= ? AND cs.end_ts <= ?`
+      params.push(timeFilter.startTs, timeFilter.endTs)
+    }
+
+    // 关键词过滤：只返回包含关键词的会话
+    if (keywords && keywords.length > 0) {
+      const keywordConditions = keywords.map(() => `m.content LIKE ?`).join(' OR ')
+      sessionSql += `
+        AND cs.id IN (
+          SELECT DISTINCT mc.session_id
+          FROM message_context mc
+          JOIN message m ON m.id = mc.message_id
+          WHERE (${keywordConditions})
+        )
+      `
+      for (const kw of keywords) {
+        params.push(`%${kw}%`)
+      }
+    }
+
+    sessionSql += ` ORDER BY cs.start_ts DESC LIMIT ?`
+    params.push(limit)
+
+    const sessions = db.prepare(sessionSql).all(...params) as Array<{
+      id: number
+      startTs: number
+      endTs: number
+      messageCount: number
+    }>
+
+    // 2. 为每个会话获取预览消息
+    const previewSql = `
+      SELECT
+        m.id,
+        COALESCE(mb.group_nickname, mb.account_name, mb.platform_id) as senderName,
+        m.content,
+        m.ts as timestamp
+      FROM message_context mc
+      JOIN message m ON m.id = mc.message_id
+      JOIN member mb ON mb.id = m.sender_id
+      WHERE mc.session_id = ?
+      ORDER BY m.ts ASC
+      LIMIT ?
+    `
+
+    const results: SessionSearchResultItem[] = []
+    for (const session of sessions) {
+      const previewMessages = db.prepare(previewSql).all(session.id, previewCount) as Array<{
+        id: number
+        senderName: string
+        content: string | null
+        timestamp: number
+      }>
+
+      results.push({
+        id: session.id,
+        startTs: session.startTs,
+        endTs: session.endTs,
+        messageCount: session.messageCount,
+        isComplete: session.messageCount <= previewCount,
+        previewMessages,
+      })
+    }
+
+    return results
+  } catch (error) {
+    console.error('searchSessions error:', error)
+    return []
+  } finally {
+    db.close()
+  }
+}
+
+/**
+ * 会话消息结果类型（用于 AI 工具）
+ */
+export interface SessionMessagesResult {
+  sessionId: number
+  startTs: number
+  endTs: number
+  messageCount: number
+  returnedCount: number
+  /** 参与者列表 */
+  participants: string[]
+  /** 消息列表 */
+  messages: Array<{
+    id: number
+    senderName: string
+    content: string | null
+    timestamp: number
+  }>
+}
+
+/**
+ * 获取会话的完整消息（用于 AI 工具）
+ *
+ * @param sessionId 数据库会话ID
+ * @param chatSessionId 会话索引中的会话ID
+ * @param limit 返回数量限制，默认 500
+ * @returns 会话的完整消息
+ */
+export function getSessionMessages(
+  sessionId: string,
+  chatSessionId: number,
+  limit: number = 500
+): SessionMessagesResult | null {
+  const db = openReadonlyDatabase(sessionId)
+  if (!db) {
+    return null
+  }
+
+  try {
+    // 1. 获取会话基本信息
+    const sessionSql = `
+      SELECT
+        id,
+        start_ts as startTs,
+        end_ts as endTs,
+        message_count as messageCount
+      FROM chat_session
+      WHERE id = ?
+    `
+    const session = db.prepare(sessionSql).get(chatSessionId) as
+      | {
+          id: number
+          startTs: number
+          endTs: number
+          messageCount: number
+        }
+      | undefined
+
+    if (!session) {
+      return null
+    }
+
+    // 2. 获取会话消息
+    const messagesSql = `
+      SELECT
+        m.id,
+        COALESCE(mb.group_nickname, mb.account_name, mb.platform_id) as senderName,
+        m.content,
+        m.ts as timestamp
+      FROM message_context mc
+      JOIN message m ON m.id = mc.message_id
+      JOIN member mb ON mb.id = m.sender_id
+      WHERE mc.session_id = ?
+      ORDER BY m.ts ASC
+      LIMIT ?
+    `
+    const messages = db.prepare(messagesSql).all(chatSessionId, limit) as Array<{
+      id: number
+      senderName: string
+      content: string | null
+      timestamp: number
+    }>
+
+    // 3. 统计参与者
+    const participantsSet = new Set<string>()
+    for (const msg of messages) {
+      participantsSet.add(msg.senderName)
+    }
+
+    return {
+      sessionId: session.id,
+      startTs: session.startTs,
+      endTs: session.endTs,
+      messageCount: session.messageCount,
+      returnedCount: messages.length,
+      participants: Array.from(participantsSet),
+      messages,
+    }
+  } catch (error) {
+    console.error('getSessionMessages error:', error)
+    return null
+  } finally {
+    db.close()
+  }
+}
diff --git a/electron/main/worker/workerManager.ts b/electron/main/worker/workerManager.ts
index b9c26d8..0e97ad6 100644
--- a/electron/main/worker/workerManager.ts
+++ b/electron/main/worker/workerManager.ts
@@ -557,3 +557,64 @@ export interface ChatSessionItem {
 export async function getSessions(sessionId: string): Promise<ChatSessionItem[]> {
   return sendToWorker('getSessions', { sessionId })
 }
+
+// ==================== AI 工具专用查询函数 ====================
+
+/**
+ * 会话搜索结果项类型（用于 AI 工具）
+ */
+export interface SessionSearchResultItem {
+  id: number
+  startTs: number
+  endTs: number
+  messageCount: number
+  isComplete: boolean
+  previewMessages: Array<{
+    id: number
+    senderName: string
+    content: string | null
+    timestamp: number
+  }>
+}
+
+/**
+ * 搜索会话（用于 AI 工具）
+ */
+export async function searchSessions(
+  sessionId: string,
+  keywords?: string[],
+  timeFilter?: { startTs: number; endTs: number },
+  limit?: number,
+  previewCount?: number
+): Promise<SessionSearchResultItem[]> {
+  return sendToWorker('searchSessions', { sessionId, keywords, timeFilter, limit, previewCount })
+}
+
+/**
+ * 会话消息结果类型（用于 AI 工具）
+ */
+export interface SessionMessagesResult {
+  sessionId: number
+  startTs: number
+  endTs: number
+  messageCount: number
+  returnedCount: number
+  participants: string[]
+  messages: Array<{
+    id: number
+    senderName: string
+    content: string | null
+    timestamp: number
+  }>
+}
+
+/**
+ * 获取会话的完整消息（用于 AI 工具）
+ */
+export async function getSessionMessages(
+  sessionId: string,
+  chatSessionId: number,
+  limit?: number
+): Promise<SessionMessagesResult | null> {
+  return sendToWorker('getSessionMessages', { sessionId, chatSessionId, limit })
+}