diff --git a/config/config.yaml b/config/config.yaml
index 299269c13..4f502e851 100644
--- a/config/config.yaml
+++ b/config/config.yaml
@@ -206,7 +206,12 @@ conversation:
       - If the user asks in English, respond in English
       - If the user asks in Chinese, respond in Chinese
 
-    context_template: "{{query}}"
+    context_template: |
+      The following is retrieved information:
+      {{contexts}}
+
+      Based on the above retrieved information, answer the following question:
+      {{query}}
   extract_entities_prompt: |
     ## Task
     Extract all entities from the user-provided text that match the following entity types:
@@ -536,3 +541,39 @@ extract:
 tenant:
   # Enable cross-tenant access (can be enabled for intranet environments)
   enable_cross_tenant_access: false
+
+# IM integration configuration (optional)
+# Uncomment and configure to enable WeCom/Feishu bot integration
+#
+# mode:
+#   "webhook"   — (default) platform pushes events to your callback URL, requires public domain
+#   "websocket" — long connection, no public domain needed, SDK maintains persistent connection
+im:
+  wecom:
+    enabled: true
+    tenant_id: 10000                              # WeKnora tenant ID to use
+    agent_id: ""                              # Default agent ID (optional)
+    knowledge_base_ids: 
+      - ""                   # Default knowledge bases (optional)
+    mode: "websocket"                           # "webhook" or "websocket"
+    # --- websocket mode (智能机器人长连接) ---
+    bot_id: "${WECOM_BOT_ID}"              # 智能机器人 Bot ID
+    bot_secret: "${WECOM_BOT_SECRET}"      # 智能机器人 Secret
+    # --- webhook mode (自建应用回调) ---
+    # corp_id: "${WECOM_CORP_ID}"               # 企业微信 Corp ID
+    # agent_secret: "${WECOM_AGENT_SECRET}"     # 应用 Secret
+    # token: "${WECOM_TOKEN}"                   # 回调 Token
+    # encoding_aes_key: "${WECOM_AES_KEY}"      # 回调 EncodingAESKey
+    # corp_agent_id: 1000001                    # 应用 AgentID
+  feishu:
+    enabled: true
+    tenant_id: 10000                           # WeKnora tenant ID to use
+    agent_id: ""                              # Default agent ID (optional)
+    knowledge_base_ids:                        # Default knowledge bases
+      - ""
+    mode: "websocket"                         # "webhook" or "websocket"
+    app_id: "${FEISHU_APP_ID}"                # 飞书 App ID
+    app_secret: "${FEISHU_APP_SECRET}"        # 飞书 App Secret
+    # --- 以下仅 webhook 模式需要，websocket 模式可留空 ---
+    # verification_token: "${FEISHU_TOKEN}"   # 事件订阅 Verification Token (webhook only)
+    # encrypt_key: "${FEISHU_ENCRYPT_KEY}"    # 事件订阅 Encrypt Key (webhook only)
diff --git a/docker-compose.yml b/docker-compose.yml
index 11c731d6d..527a6d8b0 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -38,8 +38,8 @@ services:
     volumes:
       - data-files:/data/files
       - docreader-tmp:/tmp/docreader:ro
-      # Optional: mount custom config file
-      # - ./config/config.yaml:/app/config/config.yaml
+      # Mount custom config file (required for IM integration)
+      - ./config/config.yaml:/app/config/config.yaml
       # Optional: mount custom skills directory (allows adding skills without rebuilding image)
       - ./skills/preloaded:/app/skills/preloaded
     healthcheck:
@@ -114,6 +114,11 @@ services:
       - SYSTEM_AES_KEY=${SYSTEM_AES_KEY:-}
       - CONCURRENCY_POOL_SIZE=${CONCURRENCY_POOL_SIZE:-5}
       - JWT_SECRET=${JWT_SECRET:-}
+      # IM integration
+      - FEISHU_APP_ID=${FEISHU_APP_ID:-}
+      - FEISHU_APP_SECRET=${FEISHU_APP_SECRET:-}
+      - WECOM_BOT_ID=${WECOM_BOT_ID:-}
+      - WECOM_BOT_SECRET=${WECOM_BOT_SECRET:-}
       # File size limit (in MB)
       - MAX_FILE_SIZE_MB=${MAX_FILE_SIZE_MB:-50}
       # Agent Skills Sandbox
diff --git a/go.mod b/go.mod
index d949c88af..74f030efc 100644
--- a/go.mod
+++ b/go.mod
@@ -22,7 +22,9 @@ require (
 	github.com/golang-migrate/migrate/v4 v4.19.1
 	github.com/google/jsonschema-go v0.4.2
 	github.com/google/uuid v1.6.0
+	github.com/gorilla/websocket v1.5.0
 	github.com/hibiken/asynq v0.25.1
+	github.com/larksuite/oapi-sdk-go/v3 v3.5.3
 	github.com/mark3labs/mcp-go v0.43.0
 	github.com/milvus-io/milvus/client/v2 v2.6.2
 	github.com/minio/minio-go/v7 v7.0.91
@@ -167,7 +169,6 @@ require (
 	github.com/google/s2a-go v0.1.9 // indirect
 	github.com/googleapis/enterprise-certificate-proxy v0.3.7 // indirect
 	github.com/googleapis/gax-go/v2 v2.16.0 // indirect
-	github.com/gorilla/websocket v1.5.0 // indirect
 	github.com/grpc-ecosystem/go-grpc-middleware v1.4.0 // indirect
 	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 // indirect
 	github.com/grpc-ecosystem/grpc-gateway v1.16.0 // indirect
diff --git a/go.sum b/go.sum
index 48921a4dc..78b2cedf7 100644
--- a/go.sum
+++ b/go.sum
@@ -2085,6 +2085,8 @@ github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0
 github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/labstack/echo/v4 v4.5.0/go.mod h1:czIriw4a0C1dFun+ObrXp7ok03xON0N1awStJ6ArI7Y=
 github.com/labstack/gommon v0.3.0/go.mod h1:MULnywXg0yavhxWKc+lOruYdAhDwPK9wf0OL7NoOu+k=
+github.com/larksuite/oapi-sdk-go/v3 v3.5.3 h1:xvf8Dv29kBXC5/DNDCLhHkAFW8l/0LlQJimO5Zn+JUk=
+github.com/larksuite/oapi-sdk-go/v3 v3.5.3/go.mod h1:ZEplY+kwuIrj/nqw5uSCINNATcH3KdxSN7y+UxYY5fI=
 github.com/ledongthuc/pdf v0.0.0-20220302134840-0c2507a12d80 h1:6Yzfa6GP0rIo/kULo2bwGEkFvCePZ3qHDDTC3/J9Swo=
 github.com/ledongthuc/pdf v0.0.0-20220302134840-0c2507a12d80/go.mod h1:imJHygn/1yfhB7XSJJKlFZKl/J+dCPAknuiaGOshXAs=
 github.com/leodido/go-urn v1.2.0/go.mod h1:+8+nEpDfqqsY+g338gtMEUOtuK+4dEMhiQEgxpxOKII=
diff --git a/internal/config/config.go b/internal/config/config.go
index c691af6dd..6405bce99 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -27,6 +27,46 @@ type Config struct {
 	ExtractManager  *ExtractManagerConfig  `yaml:"extract"          json:"extract"`
 	WebSearch       *WebSearchConfig       `yaml:"web_search"       json:"web_search"`
 	PromptTemplates *PromptTemplatesConfig `yaml:"prompt_templates" json:"prompt_templates"`
+	IM              *IMConfig              `yaml:"im"               json:"im"`
+}
+
+// IMConfig IM 集成配置
+type IMConfig struct {
+	WeCom  *WeComIMConfig  `yaml:"wecom"  json:"wecom"`
+	Feishu *FeishuIMConfig `yaml:"feishu" json:"feishu"`
+}
+
+// WeComIMConfig 企业微信配置
+type WeComIMConfig struct {
+	Enabled        bool     `yaml:"enabled"          json:"enabled"`
+	TenantID       uint64   `yaml:"tenant_id"        json:"tenant_id"`
+	AgentID        string   `yaml:"agent_id"         json:"agent_id"`
+	KnowledgeBases []string `yaml:"knowledge_base_ids" json:"knowledge_base_ids"`
+	// Mode: "webhook" (default, requires public domain) or "websocket" (long connection via intelligent bot, no public domain needed)
+	Mode string `yaml:"mode" json:"mode"`
+	// --- Webhook mode fields (self-built app callback) ---
+	CorpID         string `yaml:"corp_id"          json:"corp_id"`
+	AgentSecret    string `yaml:"agent_secret"     json:"agent_secret"`
+	Token          string `yaml:"token"            json:"token"`
+	EncodingAESKey string `yaml:"encoding_aes_key" json:"encoding_aes_key"`
+	CorpAgentID    int    `yaml:"corp_agent_id"    json:"corp_agent_id"`
+	// --- WebSocket mode fields (intelligent bot long connection) ---
+	BotID     string `yaml:"bot_id"     json:"bot_id"`
+	BotSecret string `yaml:"bot_secret" json:"bot_secret"`
+}
+
+// FeishuIMConfig 飞书配置
+type FeishuIMConfig struct {
+	Enabled           bool     `yaml:"enabled"            json:"enabled"`
+	TenantID          uint64   `yaml:"tenant_id"          json:"tenant_id"`
+	AgentID           string   `yaml:"agent_id"           json:"agent_id"`
+	KnowledgeBases    []string `yaml:"knowledge_base_ids" json:"knowledge_base_ids"`
+	AppID             string   `yaml:"app_id"             json:"app_id"`
+	AppSecret         string   `yaml:"app_secret"         json:"app_secret"`
+	VerificationToken string   `yaml:"verification_token" json:"verification_token"`
+	EncryptKey        string   `yaml:"encrypt_key"        json:"encrypt_key"`
+	// Mode: "websocket" (default, long connection, no public domain needed) or "webhook" (requires public domain)
+	Mode string `yaml:"mode" json:"mode"`
 }
 
 // DocReaderConfig configures the document parser client (gRPC or HTTP).
diff --git a/internal/container/container.go b/internal/container/container.go
index 4475f66ef..ab1561cb2 100644
--- a/internal/container/container.go
+++ b/internal/container/container.go
@@ -52,6 +52,9 @@ import (
 	"github.com/Tencent/WeKnora/internal/event"
 	"github.com/Tencent/WeKnora/internal/handler"
 	"github.com/Tencent/WeKnora/internal/handler/session"
+	imPkg "github.com/Tencent/WeKnora/internal/im"
+	"github.com/Tencent/WeKnora/internal/im/feishu"
+	"github.com/Tencent/WeKnora/internal/im/wecom"
 	"github.com/Tencent/WeKnora/internal/infrastructure/docparser"
 	"github.com/Tencent/WeKnora/internal/logger"
 	"github.com/Tencent/WeKnora/internal/mcp"
@@ -235,6 +238,12 @@ func BuildContainer(container *dig.Container) *dig.Container {
 	must(container.Provide(service.NewSkillService))
 	must(container.Provide(handler.NewSkillHandler))
 	must(container.Provide(handler.NewOrganizationHandler))
+
+	// IM integration
+	logger.Debugf(ctx, "[Container] Registering IM integration...")
+	must(container.Provide(imPkg.NewService))
+	must(container.Invoke(registerIMAdapters))
+	must(container.Provide(handler.NewIMHandler))
 	logger.Debugf(ctx, "[Container] HTTP handlers registered")
 
 	// Router configuration
@@ -937,3 +946,115 @@ func registerWebSearchProviders(registry *web_search.Registry) {
 		return web_search.NewBingProvider()
 	})
 }
+
+// registerIMAdapters registers IM platform adapters based on configuration.
+// For "websocket" mode, it also starts a long connection client in a goroutine.
+func registerIMAdapters(cfg *config.Config, imService *imPkg.Service) {
+	if cfg.IM == nil {
+		logger.Infof(context.Background(), "[IM] No IM configuration found, skipping adapter registration")
+		return
+	}
+
+	ctx := context.Background()
+
+	// Register WeCom
+	if cfg.IM.WeCom != nil && cfg.IM.WeCom.Enabled {
+		registerWeComAdapter(ctx, cfg.IM.WeCom, imService)
+	}
+
+	// Register Feishu
+	if cfg.IM.Feishu != nil && cfg.IM.Feishu.Enabled {
+		registerFeishuAdapter(ctx, cfg.IM.Feishu, imService)
+	}
+}
+
+func registerWeComAdapter(ctx context.Context, cfg *config.WeComIMConfig, imService *imPkg.Service) {
+	mode := cfg.Mode
+	if mode == "" {
+		mode = "websocket"
+	}
+
+	switch mode {
+	case "webhook":
+		adapter, err := wecom.NewAdapter(
+			cfg.CorpID,
+			cfg.AgentSecret,
+			cfg.Token,
+			cfg.EncodingAESKey,
+			cfg.CorpAgentID,
+		)
+		if err != nil {
+			logger.Warnf(ctx, "[IM] Failed to create WeCom webhook adapter: %v", err)
+			return
+		}
+		imService.RegisterAdapter(adapter)
+		logger.Infof(ctx, "[IM] WeCom adapter registered (mode=webhook, corp_id=%s)", cfg.CorpID)
+
+	case "websocket":
+		// Build the message handler that delegates to imService.HandleMessage
+		handler := func(msgCtx context.Context, msg *imPkg.IncomingMessage) error {
+			return imService.HandleMessage(msgCtx, msg, cfg.TenantID, cfg.AgentID, cfg.KnowledgeBases)
+		}
+
+		client := wecom.NewLongConnClient(cfg.BotID, cfg.BotSecret, handler)
+
+		// Register a BotAdapter so the service can send replies via WebSocket
+		imService.RegisterAdapter(wecom.NewBotAdapter(client))
+		logger.Infof(ctx, "[IM] WeCom adapter registered (mode=websocket, bot_id=%s)", cfg.BotID)
+
+		// Start the long connection in a goroutine
+		go func() {
+			if err := client.Start(context.Background()); err != nil {
+				logger.Errorf(context.Background(), "[IM] WeCom long connection stopped: %v", err)
+			}
+		}()
+
+	default:
+		logger.Warnf(ctx, "[IM] Unknown WeCom mode: %s (expected 'webhook' or 'websocket')", mode)
+	}
+}
+
+func registerFeishuAdapter(ctx context.Context, cfg *config.FeishuIMConfig, imService *imPkg.Service) {
+	mode := cfg.Mode
+	if mode == "" {
+		mode = "websocket"
+	}
+
+	// Always register the HTTP adapter (needed for SendReply in both modes)
+	adapter := feishu.NewAdapter(
+		cfg.AppID,
+		cfg.AppSecret,
+		cfg.VerificationToken,
+		cfg.EncryptKey,
+	)
+	imService.RegisterAdapter(adapter)
+
+	switch mode {
+	case "webhook":
+		logger.Infof(ctx, "[IM] Feishu adapter registered (mode=webhook, app_id=%s)", cfg.AppID)
+
+	case "websocket":
+		logger.Infof(ctx, "[IM] Feishu adapter registered (mode=websocket, app_id=%s)", cfg.AppID)
+
+		// Build the message handler
+		handler := func(msgCtx context.Context, msg *imPkg.IncomingMessage) error {
+			return imService.HandleMessage(msgCtx, msg, cfg.TenantID, cfg.AgentID, cfg.KnowledgeBases)
+		}
+
+		client := feishu.NewLongConnClient(
+			cfg.AppID,
+			cfg.AppSecret,
+			handler,
+		)
+
+		// Start the long connection in a goroutine
+		go func() {
+			if err := client.Start(context.Background()); err != nil {
+				logger.Errorf(context.Background(), "[IM] Feishu long connection stopped: %v", err)
+			}
+		}()
+
+	default:
+		logger.Warnf(ctx, "[IM] Unknown Feishu mode: %s (expected 'webhook' or 'websocket')", mode)
+	}
+}
diff --git a/internal/handler/im.go b/internal/handler/im.go
new file mode 100644
index 000000000..66379d55c
--- /dev/null
+++ b/internal/handler/im.go
@@ -0,0 +1,132 @@
+package handler
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/Tencent/WeKnora/internal/config"
+	"github.com/Tencent/WeKnora/internal/im"
+	"github.com/Tencent/WeKnora/internal/logger"
+	"github.com/gin-gonic/gin"
+)
+
+// IMHandler handles IM platform callback requests.
+type IMHandler struct {
+	imService *im.Service
+	config    *config.Config
+}
+
+// NewIMHandler creates a new IM handler.
+func NewIMHandler(imService *im.Service, cfg *config.Config) *IMHandler {
+	return &IMHandler{
+		imService: imService,
+		config:    cfg,
+	}
+}
+
+// WeComCallback handles WeCom callback requests (both URL verification and message events).
+func (h *IMHandler) WeComCallback(c *gin.Context) {
+	ctx := c.Request.Context()
+
+	adapter, ok := h.imService.GetAdapter(im.PlatformWeCom)
+	if !ok {
+		logger.Error(ctx, "[IM] WeCom adapter not registered")
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "WeCom integration not enabled"})
+		return
+	}
+
+	// Handle URL verification (GET request)
+	if adapter.HandleURLVerification(c) {
+		return
+	}
+
+	// Verify callback signature
+	if err := adapter.VerifyCallback(c); err != nil {
+		logger.Errorf(ctx, "[IM] WeCom callback verification failed: %v", err)
+		c.JSON(http.StatusForbidden, gin.H{"error": "verification failed"})
+		return
+	}
+
+	// Parse the callback message
+	msg, err := adapter.ParseCallback(c)
+	if err != nil {
+		logger.Errorf(ctx, "[IM] WeCom parse callback failed: %v", err)
+		c.JSON(http.StatusBadRequest, gin.H{"error": "parse failed"})
+		return
+	}
+
+	// If nil, it's a non-message event (e.g., system event) - just acknowledge
+	if msg == nil {
+		c.JSON(http.StatusOK, gin.H{"success": true})
+		return
+	}
+
+	// Respond immediately to avoid WeCom timeout, process asynchronously
+	c.JSON(http.StatusOK, gin.H{"success": true})
+
+	// Get config for this platform
+	wecomCfg := h.config.IM.WeCom
+
+	// Detach from gin request context to prevent cancellation after HTTP response.
+	asyncCtx := context.WithoutCancel(ctx)
+
+	// Process message asynchronously
+	go func() {
+		if err := h.imService.HandleMessage(asyncCtx, msg, wecomCfg.TenantID, wecomCfg.AgentID, wecomCfg.KnowledgeBases); err != nil {
+			logger.Errorf(asyncCtx, "[IM] WeCom handle message error: %v", err)
+		}
+	}()
+}
+
+// FeishuCallback handles Feishu callback requests (both URL verification and message events).
+func (h *IMHandler) FeishuCallback(c *gin.Context) {
+	ctx := c.Request.Context()
+
+	adapter, ok := h.imService.GetAdapter(im.PlatformFeishu)
+	if !ok {
+		logger.Error(ctx, "[IM] Feishu adapter not registered")
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "Feishu integration not enabled"})
+		return
+	}
+
+	// Handle URL verification (challenge)
+	if adapter.HandleURLVerification(c) {
+		return
+	}
+
+	// Verify callback
+	if err := adapter.VerifyCallback(c); err != nil {
+		logger.Errorf(ctx, "[IM] Feishu callback verification failed: %v", err)
+		c.JSON(http.StatusForbidden, gin.H{"error": "verification failed"})
+		return
+	}
+
+	// Parse the callback message
+	msg, err := adapter.ParseCallback(c)
+	if err != nil {
+		logger.Errorf(ctx, "[IM] Feishu parse callback failed: %v", err)
+		c.JSON(http.StatusBadRequest, gin.H{"error": "parse failed"})
+		return
+	}
+
+	if msg == nil {
+		c.JSON(http.StatusOK, gin.H{"success": true})
+		return
+	}
+
+	// Respond immediately
+	c.JSON(http.StatusOK, gin.H{"success": true})
+
+	// Get config
+	feishuCfg := h.config.IM.Feishu
+
+	// Detach from gin request context to prevent cancellation after HTTP response.
+	asyncCtx := context.WithoutCancel(ctx)
+
+	// Process asynchronously
+	go func() {
+		if err := h.imService.HandleMessage(asyncCtx, msg, feishuCfg.TenantID, feishuCfg.AgentID, feishuCfg.KnowledgeBases); err != nil {
+			logger.Errorf(asyncCtx, "[IM] Feishu handle message error: %v", err)
+		}
+	}()
+}
diff --git a/internal/im/adapter.go b/internal/im/adapter.go
new file mode 100644
index 000000000..1cbe63968
--- /dev/null
+++ b/internal/im/adapter.go
@@ -0,0 +1,76 @@
+package im
+
+import (
+	"context"
+
+	"github.com/gin-gonic/gin"
+)
+
+// Platform identifies an IM platform.
+type Platform string
+
+const (
+	PlatformWeCom  Platform = "wecom"
+	PlatformFeishu Platform = "feishu"
+)
+
+// IncomingMessage is the unified message parsed from an IM callback.
+type IncomingMessage struct {
+	// Platform identifies which IM platform the message comes from.
+	Platform Platform
+	// UserID is the IM-platform user identifier.
+	UserID string
+	// UserName is the display name of the user (optional).
+	UserName string
+	// ChatID is the group/channel ID (empty for direct messages).
+	ChatID string
+	// ChatType distinguishes direct message from group chat.
+	ChatType ChatType
+	// Content is the text content of the message.
+	Content string
+	// MessageID is the IM-platform message identifier (for dedup).
+	MessageID string
+	// Extra holds platform-specific fields (e.g., WeCom stream ID).
+	Extra map[string]string
+}
+
+// ChatType represents the IM chat type.
+type ChatType string
+
+const (
+	ChatTypeDirect ChatType = "direct"
+	ChatTypeGroup  ChatType = "group"
+)
+
+// ReplyMessage is what WeKnora sends back to the IM platform.
+type ReplyMessage struct {
+	// Content is the text content (Markdown).
+	Content string
+	// IsStreaming indicates whether this is a streaming chunk.
+	IsStreaming bool
+	// IsFinal marks the last chunk of a streaming reply.
+	IsFinal bool
+	// Extra holds platform-specific fields.
+	Extra map[string]string
+}
+
+// Adapter is the interface every IM platform must implement.
+type Adapter interface {
+	// Platform returns the platform identifier.
+	Platform() Platform
+
+	// VerifyCallback verifies the signature/token of an incoming callback request.
+	// Returns nil if verification passes.
+	VerifyCallback(c *gin.Context) error
+
+	// ParseCallback parses the raw IM callback request into a unified IncomingMessage.
+	// Returns nil message for non-message events (e.g., URL verification).
+	ParseCallback(c *gin.Context) (*IncomingMessage, error)
+
+	// SendReply sends a reply back to the IM platform.
+	SendReply(ctx context.Context, incoming *IncomingMessage, reply *ReplyMessage) error
+
+	// HandleURLVerification handles the initial URL verification challenge from the IM platform.
+	// Returns true if this request is a verification request and has been handled.
+	HandleURLVerification(c *gin.Context) bool
+}
diff --git a/internal/im/feishu/adapter.go b/internal/im/feishu/adapter.go
new file mode 100644
index 000000000..ac5906fee
--- /dev/null
+++ b/internal/im/feishu/adapter.go
@@ -0,0 +1,424 @@
+// Package feishu implements the Feishu (飞书/Lark) IM adapter for WeKnora.
+//
+// Feishu bot flow:
+// 1. User sends a message to the bot (direct or @mention in group)
+// 2. Feishu calls our event subscription URL with the message event
+// 3. We parse the event, run QA, then call Feishu API to send reply
+// 4. For streaming: create a card, then use CardKit streaming update API
+//
+// Reference: https://open.feishu.cn/document/server-docs/im-v1/message/create
+package feishu
+
+import (
+	"bytes"
+	"context"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/Tencent/WeKnora/internal/im"
+	"github.com/Tencent/WeKnora/internal/logger"
+	"github.com/gin-gonic/gin"
+)
+
+var httpClient = &http.Client{Timeout: 10 * time.Second}
+
+// Adapter implements im.Adapter for Feishu/Lark.
+type Adapter struct {
+	appID             string
+	appSecret         string
+	verificationToken string
+	encryptKey        string
+
+	// Token cache
+	tokenMu    sync.Mutex
+	tokenCache string
+	tokenExpAt time.Time
+}
+
+// NewAdapter creates a new Feishu adapter.
+func NewAdapter(appID, appSecret, verificationToken, encryptKey string) *Adapter {
+	return &Adapter{
+		appID:             appID,
+		appSecret:         appSecret,
+		verificationToken: verificationToken,
+		encryptKey:        encryptKey,
+	}
+}
+
+// Platform returns the platform identifier.
+func (a *Adapter) Platform() im.Platform {
+	return im.PlatformFeishu
+}
+
+// VerifyCallback verifies the Feishu event callback by checking the verification token.
+// If no verification token is configured (e.g., WebSocket mode), skip verification.
+func (a *Adapter) VerifyCallback(c *gin.Context) error {
+	if a.verificationToken == "" {
+		return nil
+	}
+
+	bodyBytes, err := io.ReadAll(c.Request.Body)
+	if err != nil {
+		return fmt.Errorf("read body: %w", err)
+	}
+	// Always restore body for subsequent reads (ParseCallback)
+	defer func() { c.Request.Body = io.NopCloser(bytes.NewReader(bodyBytes)) }()
+
+	var raw []byte
+
+	// Handle encrypted events
+	var encryptedBody struct {
+		Encrypt string `json:"encrypt"`
+	}
+	if err := json.Unmarshal(bodyBytes, &encryptedBody); err == nil && encryptedBody.Encrypt != "" {
+		decrypted, err := a.decrypt(encryptedBody.Encrypt)
+		if err != nil {
+			return fmt.Errorf("decrypt event for verification: %w", err)
+		}
+		raw = decrypted
+	} else {
+		raw = bodyBytes
+	}
+
+	var eventBody struct {
+		Header *feishuEventHeader `json:"header"`
+	}
+	if err := json.Unmarshal(raw, &eventBody); err != nil {
+		return fmt.Errorf("unmarshal event header: %w", err)
+	}
+
+	if eventBody.Header == nil || eventBody.Header.Token != a.verificationToken {
+		return fmt.Errorf("invalid verification token")
+	}
+
+	return nil
+}
+
+// HandleURLVerification handles the Feishu URL verification challenge.
+func (a *Adapter) HandleURLVerification(c *gin.Context) bool {
+	bodyBytes, err := io.ReadAll(c.Request.Body)
+	if err != nil {
+		return false
+	}
+	c.Request.Body = io.NopCloser(bytes.NewReader(bodyBytes))
+
+	// Try to parse as a challenge request
+	var body map[string]interface{}
+
+	// If encrypted, try to decrypt first
+	var encryptedBody struct {
+		Encrypt string `json:"encrypt"`
+	}
+	if err := json.Unmarshal(bodyBytes, &encryptedBody); err == nil && encryptedBody.Encrypt != "" {
+		decrypted, err := a.decrypt(encryptedBody.Encrypt)
+		if err != nil {
+			logger.Errorf(c.Request.Context(), "[Feishu] Failed to decrypt: %v", err)
+			return false
+		}
+		if err := json.Unmarshal(decrypted, &body); err != nil {
+			return false
+		}
+	} else {
+		if err := json.Unmarshal(bodyBytes, &body); err != nil {
+			return false
+		}
+	}
+
+	// Check if this is a URL verification challenge
+	if challenge, ok := body["challenge"].(string); ok {
+		c.JSON(http.StatusOK, gin.H{"challenge": challenge})
+		return true
+	}
+
+	// Reset body for subsequent reads
+	c.Request.Body = io.NopCloser(bytes.NewReader(bodyBytes))
+	return false
+}
+
+// feishuEventBody is the typed structure of a Feishu event callback.
+type feishuEventBody struct {
+	Header *feishuEventHeader `json:"header"`
+	Event  *feishuEvent       `json:"event"`
+}
+
+type feishuEventHeader struct {
+	EventType string `json:"event_type"`
+	Token     string `json:"token"`
+}
+
+type feishuEvent struct {
+	Message *feishuMessage `json:"message"`
+	Sender  *feishuSender  `json:"sender"`
+}
+
+type feishuMessage struct {
+	MessageID   string `json:"message_id"`
+	MessageType string `json:"message_type"`
+	ChatType    string `json:"chat_type"`
+	ChatID      string `json:"chat_id"`
+	Content     string `json:"content"`
+}
+
+type feishuSender struct {
+	SenderID *feishuSenderID `json:"sender_id"`
+}
+
+type feishuSenderID struct {
+	OpenID string `json:"open_id"`
+}
+
+// ParseCallback parses a Feishu event callback into a unified IncomingMessage.
+func (a *Adapter) ParseCallback(c *gin.Context) (*im.IncomingMessage, error) {
+	bodyBytes, err := io.ReadAll(c.Request.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read body: %w", err)
+	}
+
+	var raw []byte
+
+	// Handle encrypted events
+	var encryptedBody struct {
+		Encrypt string `json:"encrypt"`
+	}
+	if err := json.Unmarshal(bodyBytes, &encryptedBody); err == nil && encryptedBody.Encrypt != "" {
+		decrypted, err := a.decrypt(encryptedBody.Encrypt)
+		if err != nil {
+			return nil, fmt.Errorf("decrypt event: %w", err)
+		}
+		raw = decrypted
+	} else {
+		raw = bodyBytes
+	}
+
+	var eventBody feishuEventBody
+	if err := json.Unmarshal(raw, &eventBody); err != nil {
+		return nil, fmt.Errorf("unmarshal event: %w", err)
+	}
+
+	// Token verification is handled by VerifyCallback; no need to re-check here.
+
+	// Check event type
+	if eventBody.Header == nil || eventBody.Header.EventType != "im.message.receive_v1" {
+		if eventBody.Header != nil {
+			logger.Infof(c.Request.Context(), "[Feishu] Ignoring event type: %s", eventBody.Header.EventType)
+		}
+		return nil, nil
+	}
+
+	// Extract message info
+	if eventBody.Event == nil || eventBody.Event.Message == nil {
+		return nil, nil
+	}
+	msg := eventBody.Event.Message
+
+	if msg.MessageType != "text" {
+		logger.Infof(c.Request.Context(), "[Feishu] Ignoring non-text message type: %s", msg.MessageType)
+		return nil, nil
+	}
+
+	// Parse text content
+	var textContent struct {
+		Text string `json:"text"`
+	}
+	if err := json.Unmarshal([]byte(msg.Content), &textContent); err != nil {
+		return nil, fmt.Errorf("unmarshal text content: %w", err)
+	}
+
+	// Determine chat type
+	chatType := im.ChatTypeDirect
+	chatID := ""
+	if msg.ChatType == "group" {
+		chatType = im.ChatTypeGroup
+		chatID = msg.ChatID
+	}
+
+	// Get sender info
+	openID := ""
+	if eventBody.Event.Sender != nil && eventBody.Event.Sender.SenderID != nil {
+		openID = eventBody.Event.Sender.SenderID.OpenID
+	}
+
+	// Strip @bot mention from group messages
+	content := textContent.Text
+	if chatType == im.ChatTypeGroup {
+		// Feishu @mentions are in the format @_user_xxx
+		for strings.HasPrefix(content, "@_user_") {
+			idx := strings.Index(content, " ")
+			if idx >= 0 {
+				content = content[idx+1:]
+			} else {
+				break
+			}
+		}
+	}
+
+	return &im.IncomingMessage{
+		Platform:  im.PlatformFeishu,
+		UserID:    openID,
+		ChatID:    chatID,
+		ChatType:  chatType,
+		Content:   strings.TrimSpace(content),
+		MessageID: msg.MessageID,
+	}, nil
+}
+
+// SendReply sends a reply message via Feishu API.
+func (a *Adapter) SendReply(ctx context.Context, incoming *im.IncomingMessage, reply *im.ReplyMessage) error {
+	accessToken, err := a.getTenantAccessToken(ctx)
+	if err != nil {
+		return fmt.Errorf("get access token: %w", err)
+	}
+
+	// Determine receive_id_type and receive_id
+	receiveIDType := "open_id"
+	receiveID := incoming.UserID
+	if incoming.ChatType == im.ChatTypeGroup && incoming.ChatID != "" {
+		receiveIDType = "chat_id"
+		receiveID = incoming.ChatID
+	}
+
+	// Build text message
+	content, _ := json.Marshal(map[string]string{"text": reply.Content})
+	payload := map[string]interface{}{
+		"receive_id": receiveID,
+		"msg_type":   "text",
+		"content":    string(content),
+	}
+
+	payloadBytes, _ := json.Marshal(payload)
+
+	url := fmt.Sprintf("https://open.feishu.cn/open-apis/im/v1/messages?receive_id_type=%s", receiveIDType)
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(payloadBytes))
+	if err != nil {
+		return fmt.Errorf("create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json; charset=utf-8")
+	req.Header.Set("Authorization", "Bearer "+accessToken)
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("send message: %w", err)
+	}
+	defer resp.Body.Close()
+
+	var result struct {
+		Code int    `json:"code"`
+		Msg  string `json:"msg"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return fmt.Errorf("decode response: %w", err)
+	}
+	if result.Code != 0 {
+		return fmt.Errorf("feishu api error: code=%d msg=%s", result.Code, result.Msg)
+	}
+
+	return nil
+}
+
+// getTenantAccessToken retrieves the Feishu tenant access token with caching.
+// Feishu tokens expire in 2 hours; we cache with a safety margin.
+func (a *Adapter) getTenantAccessToken(ctx context.Context) (string, error) {
+	a.tokenMu.Lock()
+	defer a.tokenMu.Unlock()
+
+	if a.tokenCache != "" && time.Now().Before(a.tokenExpAt) {
+		return a.tokenCache, nil
+	}
+
+	payload, _ := json.Marshal(map[string]string{
+		"app_id":     a.appID,
+		"app_secret": a.appSecret,
+	})
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost,
+		"https://open.feishu.cn/open-apis/auth/v3/tenant_access_token/internal",
+		bytes.NewReader(payload))
+	if err != nil {
+		return "", fmt.Errorf("create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json; charset=utf-8")
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("request token: %w", err)
+	}
+	defer resp.Body.Close()
+
+	var result struct {
+		Code              int    `json:"code"`
+		Msg               string `json:"msg"`
+		TenantAccessToken string `json:"tenant_access_token"`
+		Expire            int    `json:"expire"` // seconds
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return "", fmt.Errorf("decode response: %w", err)
+	}
+	if result.Code != 0 {
+		return "", fmt.Errorf("get token error: code=%d msg=%s", result.Code, result.Msg)
+	}
+
+	a.tokenCache = result.TenantAccessToken
+	// Cache with 5-minute safety margin
+	ttl := time.Duration(result.Expire) * time.Second
+	if ttl > 5*time.Minute {
+		ttl -= 5 * time.Minute
+	}
+	a.tokenExpAt = time.Now().Add(ttl)
+
+	return a.tokenCache, nil
+}
+
+// decrypt decrypts a Feishu encrypted event body.
+// Feishu uses AES-256-CBC with SHA-256 of the encrypt key as the AES key.
+func (a *Adapter) decrypt(encrypted string) ([]byte, error) {
+	if a.encryptKey == "" {
+		return nil, fmt.Errorf("encrypt_key not configured")
+	}
+
+	ciphertext, err := base64.StdEncoding.DecodeString(encrypted)
+	if err != nil {
+		return nil, fmt.Errorf("base64 decode: %w", err)
+	}
+
+	// SHA-256 of encrypt key as AES key
+	keyHash := sha256.Sum256([]byte(a.encryptKey))
+	block, err := aes.NewCipher(keyHash[:])
+	if err != nil {
+		return nil, fmt.Errorf("new cipher: %w", err)
+	}
+
+	if len(ciphertext) < aes.BlockSize {
+		return nil, fmt.Errorf("ciphertext too short")
+	}
+
+	iv := ciphertext[:aes.BlockSize]
+	ciphertext = ciphertext[aes.BlockSize:]
+
+	mode := cipher.NewCBCDecrypter(block, iv)
+	mode.CryptBlocks(ciphertext, ciphertext)
+
+	// Remove and verify PKCS#7 padding
+	if len(ciphertext) == 0 {
+		return nil, fmt.Errorf("empty plaintext")
+	}
+	padLen := int(ciphertext[len(ciphertext)-1])
+	if padLen > aes.BlockSize || padLen == 0 || padLen > len(ciphertext) {
+		return nil, fmt.Errorf("invalid padding")
+	}
+	for i := 0; i < padLen; i++ {
+		if ciphertext[len(ciphertext)-1-i] != byte(padLen) {
+			return nil, fmt.Errorf("invalid padding")
+		}
+	}
+
+	return ciphertext[:len(ciphertext)-padLen], nil
+}
diff --git a/internal/im/feishu/longconn.go b/internal/im/feishu/longconn.go
new file mode 100644
index 000000000..aec48f57d
--- /dev/null
+++ b/internal/im/feishu/longconn.go
@@ -0,0 +1,149 @@
+package feishu
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"github.com/Tencent/WeKnora/internal/im"
+	"github.com/Tencent/WeKnora/internal/logger"
+	"github.com/larksuite/oapi-sdk-go/v3/event/dispatcher"
+	larkim "github.com/larksuite/oapi-sdk-go/v3/service/im/v1"
+	larkws "github.com/larksuite/oapi-sdk-go/v3/ws"
+)
+
+// MessageHandler is called when an IM message is received via long connection.
+type MessageHandler func(ctx context.Context, msg *im.IncomingMessage) error
+
+// LongConnClient manages a Feishu WebSocket long connection.
+type LongConnClient struct {
+	appID    string
+	wsClient *larkws.Client
+}
+
+// NewLongConnClient creates a Feishu long connection client.
+// When a text message arrives, it converts it to IncomingMessage and calls handler.
+func NewLongConnClient(appID, appSecret string, handler MessageHandler) *LongConnClient {
+	// Long connection mode does not require verificationToken or encryptKey;
+	// those are only used for webhook signature verification and decryption.
+	eventHandler := dispatcher.NewEventDispatcher("", "").
+		OnP2MessageReceiveV1(func(ctx context.Context, event *larkim.P2MessageReceiveV1) error {
+			msg := convertEvent(event)
+			if msg == nil {
+				return nil
+			}
+			return handler(ctx, msg)
+		})
+
+	sdkLogger := &feishuLoggerAdapter{appID: appID}
+
+	wsClient := larkws.NewClient(appID, appSecret,
+		larkws.WithEventHandler(eventHandler),
+		larkws.WithAutoReconnect(true),
+		larkws.WithLogger(sdkLogger),
+	)
+
+	return &LongConnClient{appID: appID, wsClient: wsClient}
+}
+
+// Start begins the WebSocket long connection. It blocks until ctx is cancelled.
+func (c *LongConnClient) Start(ctx context.Context) error {
+	logger.Infof(ctx, "[IM] Feishu WebSocket connecting (app_id=%s)...", c.appID)
+	return c.wsClient.Start(ctx)
+}
+
+// feishuLoggerAdapter bridges the Feishu SDK logger to our unified logger,
+// replacing raw SDK connection messages with a consistent format.
+type feishuLoggerAdapter struct {
+	appID string
+}
+
+func (l *feishuLoggerAdapter) Debug(ctx context.Context, args ...interface{}) {
+	logger.Debugf(ctx, "[Feishu] %s", fmt.Sprint(args...))
+}
+
+func (l *feishuLoggerAdapter) Info(ctx context.Context, args ...interface{}) {
+	msg := fmt.Sprint(args...)
+	if strings.HasPrefix(msg, "connected to ") {
+		logger.Infof(ctx, "[IM] Feishu WebSocket connected successfully (app_id=%s)", l.appID)
+		return
+	}
+	logger.Infof(ctx, "[Feishu] %s", msg)
+}
+
+func (l *feishuLoggerAdapter) Warn(ctx context.Context, args ...interface{}) {
+	logger.Warnf(ctx, "[Feishu] %s", fmt.Sprint(args...))
+}
+
+func (l *feishuLoggerAdapter) Error(ctx context.Context, args ...interface{}) {
+	logger.Errorf(ctx, "[Feishu] %s", fmt.Sprint(args...))
+}
+
+// convertEvent converts a Feishu SDK event to a unified IncomingMessage.
+// Returns nil for non-text messages.
+func convertEvent(event *larkim.P2MessageReceiveV1) *im.IncomingMessage {
+	if event == nil || event.Event == nil || event.Event.Message == nil {
+		return nil
+	}
+
+	msg := event.Event.Message
+	if msg.MessageType == nil || *msg.MessageType != "text" {
+		return nil
+	}
+
+	// Parse text content from JSON: {"text": "..."}
+	var textContent struct {
+		Text string `json:"text"`
+	}
+	if msg.Content == nil {
+		return nil
+	}
+	if err := json.Unmarshal([]byte(*msg.Content), &textContent); err != nil {
+		return nil
+	}
+
+	// Sender info
+	openID := ""
+	if event.Event.Sender != nil && event.Event.Sender.SenderId != nil && event.Event.Sender.SenderId.OpenId != nil {
+		openID = *event.Event.Sender.SenderId.OpenId
+	}
+
+	// Chat type
+	chatType := im.ChatTypeDirect
+	chatID := ""
+	if msg.ChatType != nil && *msg.ChatType == "group" {
+		chatType = im.ChatTypeGroup
+		if msg.ChatId != nil {
+			chatID = *msg.ChatId
+		}
+	}
+
+	// Message ID
+	messageID := ""
+	if msg.MessageId != nil {
+		messageID = *msg.MessageId
+	}
+
+	// Strip @bot mention from group messages
+	content := textContent.Text
+	if chatType == im.ChatTypeGroup {
+		for strings.HasPrefix(content, "@_user_") {
+			idx := strings.Index(content, " ")
+			if idx >= 0 {
+				content = content[idx+1:]
+			} else {
+				break
+			}
+		}
+	}
+
+	return &im.IncomingMessage{
+		Platform:  im.PlatformFeishu,
+		UserID:    openID,
+		ChatID:    chatID,
+		ChatType:  chatType,
+		Content:   strings.TrimSpace(content),
+		MessageID: messageID,
+	}
+}
diff --git a/internal/im/service.go b/internal/im/service.go
new file mode 100644
index 000000000..6fff47d05
--- /dev/null
+++ b/internal/im/service.go
@@ -0,0 +1,378 @@
+package im
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/Tencent/WeKnora/internal/event"
+	"github.com/Tencent/WeKnora/internal/logger"
+	"github.com/Tencent/WeKnora/internal/types"
+	"github.com/Tencent/WeKnora/internal/types/interfaces"
+	"github.com/google/uuid"
+	"gorm.io/gorm"
+)
+
+const (
+	// qaTimeout is the maximum time to wait for the QA pipeline to complete.
+	qaTimeout = 120 * time.Second
+	// dedupTTL is how long processed message IDs are retained.
+	dedupTTL = 5 * time.Minute
+	// dedupCleanupInterval is how often the dedup map is cleaned.
+	dedupCleanupInterval = 1 * time.Minute
+	// maxContentLength is the maximum allowed message content length.
+	maxContentLength = 4096
+)
+
+// Service orchestrates IM message handling:
+// 1. Receives a unified IncomingMessage from an Adapter
+// 2. Resolves or creates a WeKnora session for the IM channel
+// 3. Calls the WeKnora QA pipeline
+// 4. Collects the streaming answer and sends it back via the Adapter
+type Service struct {
+	db             *gorm.DB
+	sessionService interfaces.SessionService
+	messageService interfaces.MessageService
+	tenantService  interfaces.TenantService
+	agentService   interfaces.CustomAgentService
+
+	adapters map[Platform]Adapter
+	mu       sync.RWMutex
+
+	// processedMsgs tracks recently processed message IDs to prevent duplicate handling.
+	processedMsgs sync.Map
+
+	stopCh chan struct{}
+}
+
+// NewService creates a new IM service.
+func NewService(
+	db *gorm.DB,
+	sessionService interfaces.SessionService,
+	messageService interfaces.MessageService,
+	tenantService interfaces.TenantService,
+	agentService interfaces.CustomAgentService,
+) *Service {
+	s := &Service{
+		db:             db,
+		sessionService: sessionService,
+		messageService: messageService,
+		tenantService:  tenantService,
+		agentService:   agentService,
+		adapters:       make(map[Platform]Adapter),
+		stopCh:         make(chan struct{}),
+	}
+
+	// Start periodic dedup cleanup instead of per-message goroutines
+	go s.dedupCleanupLoop()
+
+	return s
+}
+
+// Stop gracefully shuts down the service, stopping background goroutines.
+func (s *Service) Stop() {
+	close(s.stopCh)
+}
+
+// dedupCleanupLoop periodically cleans up expired entries from the dedup map.
+func (s *Service) dedupCleanupLoop() {
+	ticker := time.NewTicker(dedupCleanupInterval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			cutoff := time.Now().Add(-dedupTTL)
+			s.processedMsgs.Range(func(key, value interface{}) bool {
+				if t, ok := value.(time.Time); ok && t.Before(cutoff) {
+					s.processedMsgs.Delete(key)
+				}
+				return true
+			})
+		case <-s.stopCh:
+			return
+		}
+	}
+}
+
+// RegisterAdapter registers an IM platform adapter.
+func (s *Service) RegisterAdapter(adapter Adapter) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.adapters[adapter.Platform()] = adapter
+}
+
+// GetAdapter returns the adapter for a given platform.
+func (s *Service) GetAdapter(platform Platform) (Adapter, bool) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	a, ok := s.adapters[platform]
+	return a, ok
+}
+
+// HandleMessage processes an incoming IM message end-to-end:
+// resolves session, runs QA, sends reply.
+func (s *Service) HandleMessage(ctx context.Context, msg *IncomingMessage, tenantID uint64, agentID string, kbIDs []string) error {
+	// Dedup: skip if this message was already processed (IM platforms may retry)
+	if msg.MessageID != "" {
+		if _, loaded := s.processedMsgs.LoadOrStore(msg.MessageID, time.Now()); loaded {
+			logger.Infof(ctx, "[IM] Skipping duplicate message: %s", msg.MessageID)
+			return nil
+		}
+	}
+
+	// Reject overly long messages to protect the QA pipeline
+	contentRunes := []rune(msg.Content)
+	if len(contentRunes) > maxContentLength {
+		logger.Warnf(ctx, "[IM] Message too long (%d runes), truncating to %d", len(contentRunes), maxContentLength)
+		msg.Content = string(contentRunes[:maxContentLength])
+	}
+
+	logger.Infof(ctx, "[IM] HandleMessage: platform=%s user=%s chat=%s content_len=%d",
+		msg.Platform, msg.UserID, msg.ChatID, len(msg.Content))
+
+	// 1. Get tenant (once, shared across resolve + QA)
+	tenant, err := s.tenantService.GetTenantByID(ctx, tenantID)
+	if err != nil {
+		return fmt.Errorf("get tenant: %w", err)
+	}
+	sessionCtx := context.WithValue(ctx, types.TenantIDContextKey, tenantID)
+	sessionCtx = context.WithValue(sessionCtx, types.TenantInfoContextKey, tenant)
+
+	// 2. Resolve or create a WeKnora session
+	channelSession, err := s.resolveSession(sessionCtx, msg, tenantID, agentID)
+	if err != nil {
+		return fmt.Errorf("resolve session: %w", err)
+	}
+
+	// 3. Get the WeKnora session
+	session, err := s.sessionService.GetSession(sessionCtx, channelSession.SessionID)
+	if err != nil {
+		return fmt.Errorf("get session: %w", err)
+	}
+
+	// 4. Resolve custom agent (optional)
+	var customAgent *types.CustomAgent
+	if agentID != "" {
+		agent, err := s.agentService.GetAgentByID(sessionCtx, agentID)
+		if err != nil {
+			logger.Warnf(ctx, "[IM] Failed to get agent %s: %v, using default", agentID, err)
+		} else {
+			customAgent = agent
+		}
+	}
+
+	// 5. Run the QA pipeline and collect the full answer
+	answer, err := s.runQA(sessionCtx, session, msg.Content, customAgent, kbIDs)
+	if err != nil {
+		logger.Errorf(ctx, "[IM] QA failed: %v, sending fallback reply", err)
+		answer = "抱歉，处理您的问题时出现了异常，请稍后再试。"
+	}
+
+	// 6. Send the reply back via the platform adapter
+	adapter, ok := s.GetAdapter(msg.Platform)
+	if !ok {
+		return fmt.Errorf("no adapter for platform: %s", msg.Platform)
+	}
+
+	reply := &ReplyMessage{
+		Content: answer,
+		IsFinal: true,
+	}
+	if err := adapter.SendReply(ctx, msg, reply); err != nil {
+		return fmt.Errorf("send reply: %w", err)
+	}
+
+	logger.Infof(ctx, "[IM] Reply sent: platform=%s user=%s answer_len=%d", msg.Platform, msg.UserID, len(answer))
+	return nil
+}
+
+// resolveSession finds or creates a ChannelSession for the given IM message.
+// ctx must already carry TenantIDContextKey and TenantInfoContextKey.
+func (s *Service) resolveSession(ctx context.Context, msg *IncomingMessage, tenantID uint64, agentID string) (*ChannelSession, error) {
+	var cs ChannelSession
+	result := s.db.Where("platform = ? AND user_id = ? AND chat_id = ? AND tenant_id = ? AND deleted_at IS NULL",
+		string(msg.Platform), msg.UserID, msg.ChatID, tenantID).
+		First(&cs)
+
+	if result.Error == nil {
+		return &cs, nil
+	}
+
+	if result.Error != gorm.ErrRecordNotFound {
+		return nil, fmt.Errorf("query channel session: %w", result.Error)
+	}
+
+	// Create a new WeKnora session
+	title := fmt.Sprintf("IM-%s", msg.Platform)
+	if msg.UserName != "" {
+		title = fmt.Sprintf("IM-%s-%s", msg.Platform, msg.UserName)
+	}
+
+	newSession := &types.Session{
+		TenantID:    tenantID,
+		Title:       title,
+		Description: fmt.Sprintf("Auto-created from %s IM integration", msg.Platform),
+	}
+
+	createdSession, err := s.sessionService.CreateSession(ctx, newSession)
+	if err != nil {
+		return nil, fmt.Errorf("create session: %w", err)
+	}
+
+	// Create the channel-session mapping; use a unique constraint fallback
+	// to handle concurrent creation attempts for the same channel.
+	cs = ChannelSession{
+		Platform:  string(msg.Platform),
+		UserID:    msg.UserID,
+		ChatID:    msg.ChatID,
+		SessionID: createdSession.ID,
+		TenantID:  tenantID,
+		AgentID:   agentID,
+	}
+	if err := s.db.Create(&cs).Error; err != nil {
+		// If the insert failed due to unique constraint (concurrent request),
+		// fetch the existing record.
+		var existing ChannelSession
+		if findErr := s.db.Where("platform = ? AND user_id = ? AND chat_id = ? AND tenant_id = ? AND deleted_at IS NULL",
+			string(msg.Platform), msg.UserID, msg.ChatID, tenantID).
+			First(&existing).Error; findErr != nil {
+			return nil, fmt.Errorf("create channel session: %w (lookup fallback: %v)", err, findErr)
+		}
+		return &existing, nil
+	}
+
+	logger.Infof(ctx, "[IM] Created new session mapping: channel=%s/%s/%s -> session=%s",
+		msg.Platform, msg.UserID, msg.ChatID, createdSession.ID)
+
+	return &cs, nil
+}
+
+// runQA executes the WeKnora QA pipeline and returns the full answer text.
+func (s *Service) runQA(ctx context.Context, session *types.Session, query string, customAgent *types.CustomAgent, kbIDs []string) (string, error) {
+	// Add timeout to prevent indefinite blocking
+	ctx, cancel := context.WithTimeout(ctx, qaTimeout)
+	defer cancel()
+
+	eventBus := event.NewEventBus()
+
+	// Thread-safe answer collection
+	var answerMu sync.Mutex
+	var answerBuilder strings.Builder
+	var qaErr error
+	done := make(chan struct{})
+	var closeOnce sync.Once
+	closeDone := func() { closeOnce.Do(func() { close(done) }) }
+
+	eventBus.On(event.EventAgentFinalAnswer, func(ctx context.Context, evt event.Event) error {
+		data, ok := evt.Data.(event.AgentFinalAnswerData)
+		if !ok {
+			return nil
+		}
+		answerMu.Lock()
+		answerBuilder.WriteString(data.Content)
+		answerMu.Unlock()
+		if data.Done {
+			closeDone()
+		}
+		return nil
+	})
+
+	eventBus.On(event.EventError, func(ctx context.Context, evt event.Event) error {
+		data, ok := evt.Data.(event.ErrorData)
+		if !ok {
+			return nil
+		}
+		logger.Errorf(ctx, "[IM] QA error: %s", data.Error)
+		answerMu.Lock()
+		qaErr = fmt.Errorf("QA pipeline error: %s", data.Error)
+		answerMu.Unlock()
+		closeDone()
+		return nil
+	})
+
+	// Determine whether to use agent mode
+	useAgent := customAgent != nil && customAgent.IsAgentMode()
+
+	// Generate a shared RequestID to pair user and assistant messages for history
+	requestID := uuid.New().String()
+
+	// Create user message so it appears in conversation history
+	userMsg, err := s.messageService.CreateMessage(ctx, &types.Message{
+		SessionID:   session.ID,
+		Role:        "user",
+		Content:     query,
+		RequestID:   requestID,
+		CreatedAt:   time.Now(),
+		IsCompleted: true,
+	})
+	if err != nil {
+		return "", fmt.Errorf("create user message: %w", err)
+	}
+	_ = userMsg
+
+	// Create a placeholder assistant message
+	assistantMsg, err := s.messageService.CreateMessage(ctx, &types.Message{
+		SessionID:   session.ID,
+		Role:        "assistant",
+		RequestID:   requestID,
+		CreatedAt:   time.Now(),
+		IsCompleted: false,
+	})
+	if err != nil {
+		return "", fmt.Errorf("create assistant message: %w", err)
+	}
+
+	// Run QA async
+	go func() {
+		var err error
+		if useAgent {
+			err = s.sessionService.AgentQA(ctx, session, query, assistantMsg.ID, "", eventBus, customAgent, kbIDs, nil)
+		} else {
+			err = s.sessionService.KnowledgeQA(ctx, session, query, kbIDs, nil, assistantMsg.ID, "", false, eventBus, customAgent, false)
+		}
+		if err != nil {
+			logger.Errorf(ctx, "[IM] QA execution error: %v", err)
+			answerMu.Lock()
+			qaErr = fmt.Errorf("QA execution error: %w", err)
+			answerMu.Unlock()
+			closeDone()
+		}
+	}()
+
+	// Wait for completion or timeout
+	select {
+	case <-done:
+	case <-ctx.Done():
+		// Mark assistant message as completed to avoid dangling incomplete records
+		assistantMsg.Content = "抱歉，回答超时，请稍后再试。"
+		assistantMsg.IsCompleted = true
+		// Use a fresh context since the original is cancelled
+		if updateErr := s.messageService.UpdateMessage(context.WithoutCancel(ctx), assistantMsg); updateErr != nil {
+			logger.Warnf(ctx, "[IM] Failed to update timed-out assistant message: %v", updateErr)
+		}
+		return "", fmt.Errorf("QA timed out after %v", qaTimeout)
+	}
+
+	answerMu.Lock()
+	answer := answerBuilder.String()
+	qaError := qaErr
+	answerMu.Unlock()
+
+	if answer == "" && qaError != nil {
+		return "", qaError
+	}
+	if answer == "" {
+		answer = "抱歉，我暂时无法回答这个问题。"
+	}
+
+	// Update assistant message with the final answer content
+	assistantMsg.Content = answer
+	assistantMsg.IsCompleted = true
+	if err := s.messageService.UpdateMessage(ctx, assistantMsg); err != nil {
+		logger.Warnf(ctx, "[IM] Failed to update assistant message: %v", err)
+	}
+
+	return answer, nil
+}
diff --git a/internal/im/types.go b/internal/im/types.go
new file mode 100644
index 000000000..96e7ae43d
--- /dev/null
+++ b/internal/im/types.go
@@ -0,0 +1,40 @@
+package im
+
+import (
+	"time"
+
+	"github.com/Tencent/WeKnora/internal/types"
+	"github.com/google/uuid"
+	"gorm.io/gorm"
+)
+
+// ChannelSession maps an IM channel (user+chat combination) to a WeKnora session.
+// This allows the IM integration to maintain conversation continuity.
+type ChannelSession struct {
+	ID        string         `json:"id"         gorm:"type:varchar(36);primaryKey;default:uuid_generate_v4()"`
+	Platform  string         `json:"platform"   gorm:"type:varchar(20);not null"`
+	UserID    string         `json:"user_id"    gorm:"type:varchar(128);not null"`
+	ChatID    string         `json:"chat_id"    gorm:"type:varchar(128);not null;default:''"`
+	SessionID string         `json:"session_id" gorm:"type:varchar(36);not null;index"`
+	TenantID  uint64         `json:"tenant_id"  gorm:"not null;index"`
+	AgentID   string         `json:"agent_id"   gorm:"type:varchar(36);default:''"`
+	Status    string         `json:"status"     gorm:"type:varchar(20);not null;default:'active'"`
+	Metadata  types.JSON     `json:"metadata"   gorm:"type:jsonb;default:'{}'"`
+	CreatedAt time.Time      `json:"created_at"`
+	UpdatedAt time.Time      `json:"updated_at"`
+	DeletedAt gorm.DeletedAt `json:"deleted_at" gorm:"index"`
+}
+
+func (ChannelSession) TableName() string {
+	return "im_channel_sessions"
+}
+
+func (cs *ChannelSession) BeforeCreate(tx *gorm.DB) error {
+	if cs.ID == "" {
+		cs.ID = uuid.New().String()
+	}
+	if cs.Status == "" {
+		cs.Status = "active"
+	}
+	return nil
+}
diff --git a/internal/im/wecom/adapter.go b/internal/im/wecom/adapter.go
new file mode 100644
index 000000000..98062dc44
--- /dev/null
+++ b/internal/im/wecom/adapter.go
@@ -0,0 +1,369 @@
+// Package wecom implements the WeCom (企业微信) IM adapter for WeKnora.
+//
+// WeCom Smart Bot flow:
+// 1. User sends a message to the bot (direct or @mention in group)
+// 2. WeCom calls our callback URL with the encrypted message
+// 3. We decrypt, parse, and return an immediate response (or stream response)
+// 4. For streaming: respond with msgtype="stream", WeCom pulls subsequent chunks via refresh callbacks
+//
+// Reference: https://developer.work.weixin.qq.com/document/path/101031
+package wecom
+
+import (
+	"bytes"
+	"context"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/hmac"
+	"crypto/sha1"
+	"encoding/base64"
+	"encoding/binary"
+	"encoding/json"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"net/http"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/Tencent/WeKnora/internal/im"
+	"github.com/Tencent/WeKnora/internal/logger"
+	"github.com/gin-gonic/gin"
+)
+
+var httpClient = &http.Client{Timeout: 10 * time.Second}
+
+// Adapter implements im.Adapter for WeCom.
+type Adapter struct {
+	corpID         string
+	token          string
+	encodingAESKey string
+	aesKey         []byte
+	agentSecret    string
+	corpAgentID    int
+
+	// Token cache
+	tokenMu    sync.Mutex
+	tokenCache string
+	tokenExpAt time.Time
+}
+
+// NewAdapter creates a new WeCom adapter.
+func NewAdapter(corpID, agentSecret, token, encodingAESKey string, corpAgentID int) (*Adapter, error) {
+	// Decode the AES key from base64
+	aesKey, err := base64.StdEncoding.DecodeString(encodingAESKey + "=")
+	if err != nil {
+		return nil, fmt.Errorf("decode encoding_aes_key: %w", err)
+	}
+
+	return &Adapter{
+		corpID:         corpID,
+		token:          token,
+		encodingAESKey: encodingAESKey,
+		aesKey:         aesKey,
+		agentSecret:    agentSecret,
+		corpAgentID:    corpAgentID,
+	}, nil
+}
+
+// Platform returns the platform identifier.
+func (a *Adapter) Platform() im.Platform {
+	return im.PlatformWeCom
+}
+
+// VerifyCallback verifies the WeCom callback signature.
+func (a *Adapter) VerifyCallback(c *gin.Context) error {
+	timestamp := c.Query("timestamp")
+	nonce := c.Query("nonce")
+	msgSignature := c.Query("msg_signature")
+
+	// For GET requests (URL verification), use echostr
+	// For POST requests (message callback), use request body's Encrypt field
+	var encrypt string
+	if c.Request.Method == http.MethodGet {
+		encrypt = c.Query("echostr")
+	} else {
+		var body callbackRequestBody
+		bodyBytes, err := io.ReadAll(c.Request.Body)
+		if err != nil {
+			return fmt.Errorf("read request body: %w", err)
+		}
+		c.Request.Body = io.NopCloser(bytes.NewReader(bodyBytes))
+		if err := xml.Unmarshal(bodyBytes, &body); err != nil {
+			return fmt.Errorf("unmarshal xml body: %w", err)
+		}
+		encrypt = body.Encrypt
+	}
+
+	if !a.verifySignature(msgSignature, timestamp, nonce, encrypt) {
+		return fmt.Errorf("invalid signature")
+	}
+
+	return nil
+}
+
+// HandleURLVerification handles the WeCom URL verification (GET request).
+func (a *Adapter) HandleURLVerification(c *gin.Context) bool {
+	if c.Request.Method != http.MethodGet {
+		return false
+	}
+
+	echoStr := c.Query("echostr")
+	if echoStr == "" {
+		return false
+	}
+
+	// Decrypt the echostr and return it
+	decrypted, err := a.decrypt(echoStr)
+	if err != nil {
+		logger.Errorf(c.Request.Context(), "[WeCom] Failed to decrypt echostr: %v", err)
+		c.String(http.StatusBadRequest, "decrypt failed")
+		return true
+	}
+
+	c.String(http.StatusOK, string(decrypted))
+	return true
+}
+
+// ParseCallback parses a WeCom callback into a unified IncomingMessage.
+func (a *Adapter) ParseCallback(c *gin.Context) (*im.IncomingMessage, error) {
+	bodyBytes, err := io.ReadAll(c.Request.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read body: %w", err)
+	}
+
+	var body callbackRequestBody
+	if err := xml.Unmarshal(bodyBytes, &body); err != nil {
+		return nil, fmt.Errorf("unmarshal xml: %w", err)
+	}
+
+	// Decrypt the message
+	decrypted, err := a.decrypt(body.Encrypt)
+	if err != nil {
+		return nil, fmt.Errorf("decrypt message: %w", err)
+	}
+
+	var msg wecomMessage
+	if err := xml.Unmarshal(decrypted, &msg); err != nil {
+		return nil, fmt.Errorf("unmarshal decrypted message: %w", err)
+	}
+
+	// Only handle text messages
+	if msg.MsgType != "text" {
+		logger.Infof(c.Request.Context(), "[WeCom] Ignoring non-text message type: %s", msg.MsgType)
+		return nil, nil
+	}
+
+	chatType := im.ChatTypeDirect
+	chatID := ""
+	content := msg.Content
+
+	// Check if this is a group message (has ChatId field in WeCom smart bot callback)
+	// In group chats, the content may contain @bot mention prefix that should be stripped
+	if msg.ChatID != "" {
+		chatType = im.ChatTypeGroup
+		chatID = msg.ChatID
+	}
+
+	return &im.IncomingMessage{
+		Platform:  im.PlatformWeCom,
+		UserID:    msg.FromUserName,
+		UserName:  msg.FromUserName,
+		ChatID:    chatID,
+		ChatType:  chatType,
+		Content:   strings.TrimSpace(content),
+		MessageID: msg.MsgID,
+	}, nil
+}
+
+// SendReply sends a reply message via WeCom API.
+// For simplicity, this uses the "应用消息" API to proactively send messages.
+// A production implementation would integrate with the streaming callback model.
+func (a *Adapter) SendReply(ctx context.Context, incoming *im.IncomingMessage, reply *im.ReplyMessage) error {
+	// Get access token
+	accessToken, err := a.getAccessToken(ctx)
+	if err != nil {
+		return fmt.Errorf("get access token: %w", err)
+	}
+
+	// Build message payload.
+	// Note: /cgi-bin/message/send only supports touser/toparty/totag — it does NOT
+	// support regular group chat IDs (chatid is only for appchat-created groups).
+	// So for both direct and group messages we reply to the user directly.
+	payload := map[string]interface{}{
+		"touser":  incoming.UserID,
+		"msgtype": "markdown",
+		"agentid": a.corpAgentID,
+		"markdown": map[string]string{
+			"content": reply.Content,
+		},
+	}
+
+	payloadBytes, err := json.Marshal(payload)
+	if err != nil {
+		return fmt.Errorf("marshal payload: %w", err)
+	}
+
+	sendURL := fmt.Sprintf("https://qyapi.weixin.qq.com/cgi-bin/message/send?access_token=%s", accessToken)
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, sendURL, bytes.NewReader(payloadBytes))
+	if err != nil {
+		return fmt.Errorf("create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("send message: %w", err)
+	}
+	defer resp.Body.Close()
+
+	var result struct {
+		ErrCode int    `json:"errcode"`
+		ErrMsg  string `json:"errmsg"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return fmt.Errorf("decode response: %w", err)
+	}
+	if result.ErrCode != 0 {
+		return fmt.Errorf("wecom api error: code=%d msg=%s", result.ErrCode, result.ErrMsg)
+	}
+
+	return nil
+}
+
+// getAccessToken retrieves the WeCom access token with caching.
+// WeCom tokens expire in 7200 seconds (2 hours); we cache with a safety margin.
+func (a *Adapter) getAccessToken(ctx context.Context) (string, error) {
+	a.tokenMu.Lock()
+	defer a.tokenMu.Unlock()
+
+	if a.tokenCache != "" && time.Now().Before(a.tokenExpAt) {
+		return a.tokenCache, nil
+	}
+
+	tokenURL := fmt.Sprintf("https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=%s&corpsecret=%s",
+		a.corpID, a.agentSecret)
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, tokenURL, nil)
+	if err != nil {
+		return "", fmt.Errorf("create request: %w", err)
+	}
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("request access token: %w", err)
+	}
+	defer resp.Body.Close()
+
+	var result struct {
+		ErrCode     int    `json:"errcode"`
+		ErrMsg      string `json:"errmsg"`
+		AccessToken string `json:"access_token"`
+		ExpiresIn   int    `json:"expires_in"` // seconds
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return "", fmt.Errorf("decode token response: %w", err)
+	}
+	if result.ErrCode != 0 {
+		return "", fmt.Errorf("get token error: code=%d msg=%s", result.ErrCode, result.ErrMsg)
+	}
+
+	a.tokenCache = result.AccessToken
+	// Cache with 5-minute safety margin
+	ttl := time.Duration(result.ExpiresIn) * time.Second
+	if ttl > 5*time.Minute {
+		ttl -= 5 * time.Minute
+	}
+	a.tokenExpAt = time.Now().Add(ttl)
+
+	return a.tokenCache, nil
+}
+
+// verifySignature verifies the WeCom callback signature using constant-time comparison.
+func (a *Adapter) verifySignature(signature, timestamp, nonce, encrypt string) bool {
+	parts := []string{a.token, timestamp, nonce, encrypt}
+	sort.Strings(parts)
+	combined := strings.Join(parts, "")
+
+	hash := sha1.New()
+	hash.Write([]byte(combined))
+	computed := fmt.Sprintf("%x", hash.Sum(nil))
+
+	return hmac.Equal([]byte(computed), []byte(signature))
+}
+
+// decrypt decrypts a WeCom AES-encrypted message.
+func (a *Adapter) decrypt(encrypted string) ([]byte, error) {
+	ciphertext, err := base64.StdEncoding.DecodeString(encrypted)
+	if err != nil {
+		return nil, fmt.Errorf("base64 decode: %w", err)
+	}
+
+	block, err := aes.NewCipher(a.aesKey)
+	if err != nil {
+		return nil, fmt.Errorf("new cipher: %w", err)
+	}
+
+	if len(ciphertext) < aes.BlockSize {
+		return nil, fmt.Errorf("ciphertext too short")
+	}
+
+	iv := a.aesKey[:aes.BlockSize]
+	mode := cipher.NewCBCDecrypter(block, iv)
+	mode.CryptBlocks(ciphertext, ciphertext)
+
+	// Remove and verify PKCS#7 padding
+	padLen := int(ciphertext[len(ciphertext)-1])
+	if padLen > aes.BlockSize || padLen == 0 || padLen > len(ciphertext) {
+		return nil, fmt.Errorf("invalid padding")
+	}
+	for i := 0; i < padLen; i++ {
+		if ciphertext[len(ciphertext)-1-i] != byte(padLen) {
+			return nil, fmt.Errorf("invalid padding")
+		}
+	}
+	plaintext := ciphertext[:len(ciphertext)-padLen]
+
+	// WeCom format: random(16) + msg_len(4) + msg + corp_id
+	if len(plaintext) < 20 {
+		return nil, fmt.Errorf("plaintext too short")
+	}
+
+	msgLen := binary.BigEndian.Uint32(plaintext[16:20])
+	if uint32(len(plaintext)) < 20+msgLen {
+		return nil, fmt.Errorf("message length mismatch")
+	}
+
+	msgBytes := plaintext[20 : 20+msgLen]
+
+	// Verify corp_id from plaintext tail
+	corpIDBytes := plaintext[20+msgLen:]
+	if string(corpIDBytes) != a.corpID {
+		return nil, fmt.Errorf("corp_id mismatch: expected %s, got %s", a.corpID, string(corpIDBytes))
+	}
+
+	return msgBytes, nil
+}
+
+// callbackRequestBody is the XML structure of a WeCom callback request body.
+type callbackRequestBody struct {
+	XMLName    xml.Name `xml:"xml"`
+	ToUserName string   `xml:"ToUserName"`
+	Encrypt    string   `xml:"Encrypt"`
+	AgentID    string   `xml:"AgentID"`
+}
+
+// wecomMessage is the decrypted WeCom message structure.
+type wecomMessage struct {
+	XMLName      xml.Name `xml:"xml"`
+	ToUserName   string   `xml:"ToUserName"`
+	FromUserName string   `xml:"FromUserName"`
+	CreateTime   int64    `xml:"CreateTime"`
+	MsgType      string   `xml:"MsgType"`
+	Content      string   `xml:"Content"`
+	MsgID        string   `xml:"MsgId"`
+	AgentID      string   `xml:"AgentID"`
+	ChatID       string   `xml:"ChatId"`
+}
diff --git a/internal/im/wecom/bot_adapter.go b/internal/im/wecom/bot_adapter.go
new file mode 100644
index 000000000..eccd6911e
--- /dev/null
+++ b/internal/im/wecom/bot_adapter.go
@@ -0,0 +1,42 @@
+package wecom
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/Tencent/WeKnora/internal/im"
+	"github.com/gin-gonic/gin"
+)
+
+// BotAdapter implements im.Adapter for WeCom intelligent bot (long connection mode).
+// It delegates SendReply to the WebSocket LongConnClient.
+// The webhook methods (VerifyCallback, ParseCallback, HandleURLVerification) are no-ops
+// since messages arrive via WebSocket, not HTTP.
+type BotAdapter struct {
+	client *LongConnClient
+}
+
+// NewBotAdapter creates an adapter backed by a WeCom long connection client.
+func NewBotAdapter(client *LongConnClient) *BotAdapter {
+	return &BotAdapter{client: client}
+}
+
+func (a *BotAdapter) Platform() im.Platform {
+	return im.PlatformWeCom
+}
+
+func (a *BotAdapter) VerifyCallback(c *gin.Context) error {
+	return fmt.Errorf("WeCom bot adapter does not support webhook callbacks")
+}
+
+func (a *BotAdapter) ParseCallback(c *gin.Context) (*im.IncomingMessage, error) {
+	return nil, fmt.Errorf("WeCom bot adapter does not support webhook callbacks")
+}
+
+func (a *BotAdapter) HandleURLVerification(c *gin.Context) bool {
+	return false
+}
+
+func (a *BotAdapter) SendReply(ctx context.Context, incoming *im.IncomingMessage, reply *im.ReplyMessage) error {
+	return a.client.SendReply(ctx, incoming, reply)
+}
diff --git a/internal/im/wecom/longconn.go b/internal/im/wecom/longconn.go
new file mode 100644
index 000000000..df04ee9ca
--- /dev/null
+++ b/internal/im/wecom/longconn.go
@@ -0,0 +1,353 @@
+// WeCom Intelligent Bot long connection client.
+//
+// Protocol reference: https://developer.work.weixin.qq.com/document/path/101463
+// Node.js SDK reference: https://github.com/WecomTeam/aibot-node-sdk
+//
+// Flow:
+//  1. Connect to wss://openws.work.weixin.qq.com
+//  2. Send aibot_subscribe with bot_id + secret
+//  3. Receive aibot_msg_callback / aibot_event_callback frames
+//  4. Reply via aibot_respond_msg on the same WebSocket
+//  5. Heartbeat via ping/pong every 30s
+package wecom
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"math"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/Tencent/WeKnora/internal/im"
+	"github.com/Tencent/WeKnora/internal/logger"
+	ws "github.com/gorilla/websocket"
+)
+
+const (
+	wecomWSEndpoint = "wss://openws.work.weixin.qq.com"
+
+	cmdSubscribe     = "aibot_subscribe"
+	cmdPing          = "ping"
+	cmdMsgCallback   = "aibot_msg_callback"
+	cmdEventCallback = "aibot_event_callback"
+	cmdResponse      = "aibot_respond_msg"
+
+	defaultHeartbeatInterval    = 30 * time.Second
+	defaultReconnectBaseDelay   = 1 * time.Second
+	defaultReconnectMaxDelay    = 30 * time.Second
+	defaultMaxReconnectAttempts = -1 // infinite
+)
+
+// wsFrame is the JSON frame exchanged over the WeCom bot WebSocket.
+type wsFrame struct {
+	Cmd     string            `json:"cmd,omitempty"`
+	Headers map[string]string `json:"headers,omitempty"`
+	Body    json.RawMessage   `json:"body,omitempty"`
+	ErrCode int               `json:"errcode,omitempty"`
+	ErrMsg  string            `json:"errmsg,omitempty"`
+}
+
+// botMessage is the body of an aibot_msg_callback frame.
+type botMessage struct {
+	MsgID      string `json:"msgid"`
+	AiBotID    string `json:"aibotid"`
+	ChatID     string `json:"chatid"`
+	ChatType   string `json:"chattype"` // "single" or "group"
+	MsgType    string `json:"msgtype"`  // "text", "image", "event", ...
+	CreateTime int64  `json:"create_time"`
+	From       struct {
+		UserID string `json:"userid"`
+	} `json:"from"`
+	Text struct {
+		Content string `json:"content"`
+	} `json:"text"`
+}
+
+// streamReplyBody is the body for a streaming text reply.
+type streamReplyBody struct {
+	MsgType string `json:"msgtype"`
+	Stream  struct {
+		ID      string `json:"id"`
+		Finish  bool   `json:"finish"`
+		Content string `json:"content"`
+	} `json:"stream"`
+}
+
+// MessageHandler is called when an IM message is received via long connection.
+type MessageHandler func(ctx context.Context, msg *im.IncomingMessage) error
+
+// LongConnClient manages a WeCom intelligent bot WebSocket long connection.
+type LongConnClient struct {
+	botID   string
+	secret  string
+	handler MessageHandler
+
+	conn   *ws.Conn
+	mu     sync.Mutex
+	closed atomic.Bool
+	reqSeq atomic.Int64
+}
+
+// NewLongConnClient creates a WeCom long connection client.
+func NewLongConnClient(botID, secret string, handler MessageHandler) *LongConnClient {
+	return &LongConnClient{
+		botID:   botID,
+		secret:  secret,
+		handler: handler,
+	}
+}
+
+// Start connects and runs the long connection loop. It reconnects automatically on failure.
+func (c *LongConnClient) Start(ctx context.Context) error {
+	logger.Infof(ctx, "[IM] WeCom WebSocket connecting (bot_id=%s)...", c.botID)
+
+	attempts := 0
+	for {
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+
+		err := c.connectAndRun(ctx)
+		if c.closed.Load() {
+			return nil
+		}
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+
+		attempts++
+		if defaultMaxReconnectAttempts >= 0 && attempts >= defaultMaxReconnectAttempts {
+			return fmt.Errorf("max reconnect attempts reached: %w", err)
+		}
+
+		delay := reconnectDelay(attempts)
+		logger.Warnf(ctx, "[WeCom] Connection lost (%v), reconnecting in %v (attempt %d)...", err, delay, attempts)
+
+		select {
+		case <-time.After(delay):
+		case <-ctx.Done():
+			return ctx.Err()
+		}
+	}
+}
+
+// Stop gracefully closes the connection.
+func (c *LongConnClient) Stop() {
+	c.closed.Store(true)
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.conn != nil {
+		_ = c.conn.Close()
+		c.conn = nil
+	}
+}
+
+// SendReply sends a text reply through the WebSocket connection.
+// This is used by the IM service to reply to messages in long connection mode.
+func (c *LongConnClient) SendReply(ctx context.Context, incoming *im.IncomingMessage, reply *im.ReplyMessage) error {
+	reqID, ok := incoming.Extra["req_id"]
+	if !ok || reqID == "" {
+		return fmt.Errorf("missing req_id in incoming message extra")
+	}
+
+	// Generate a unique stream ID for this reply
+	streamID := fmt.Sprintf("stream_%d", c.reqSeq.Add(1))
+
+	body := streamReplyBody{MsgType: "stream"}
+	body.Stream.ID = streamID
+	body.Stream.Finish = true
+	body.Stream.Content = reply.Content
+
+	bodyBytes, err := json.Marshal(body)
+	if err != nil {
+		return fmt.Errorf("marshal reply body: %w", err)
+	}
+
+	frame := wsFrame{
+		Cmd:     cmdResponse,
+		Headers: map[string]string{"req_id": reqID},
+		Body:    bodyBytes,
+	}
+
+	return c.writeJSON(frame)
+}
+
+func (c *LongConnClient) connectAndRun(ctx context.Context) error {
+	conn, _, err := ws.DefaultDialer.DialContext(ctx, wecomWSEndpoint, nil)
+	if err != nil {
+		return fmt.Errorf("dial: %w", err)
+	}
+
+	c.mu.Lock()
+	c.conn = conn
+	c.mu.Unlock()
+
+	defer func() {
+		c.mu.Lock()
+		c.conn = nil
+		c.mu.Unlock()
+		_ = conn.Close()
+	}()
+
+	// Authenticate
+	if err := c.authenticate(ctx); err != nil {
+		return fmt.Errorf("authenticate: %w", err)
+	}
+
+	logger.Infof(ctx, "[IM] WeCom WebSocket connected successfully (bot_id=%s)", c.botID)
+
+	// Start heartbeat
+	heartbeatCtx, heartbeatCancel := context.WithCancel(ctx)
+	defer heartbeatCancel()
+	go c.heartbeatLoop(heartbeatCtx)
+
+	// Message receive loop
+	for {
+		_, message, err := conn.ReadMessage()
+		if err != nil {
+			return fmt.Errorf("read message: %w", err)
+		}
+
+		var frame wsFrame
+		if err := json.Unmarshal(message, &frame); err != nil {
+			logger.Warnf(ctx, "[WeCom] Failed to unmarshal frame: %v", err)
+			continue
+		}
+
+		switch frame.Cmd {
+		case cmdMsgCallback, cmdEventCallback:
+			// Detach from connection ctx so in-flight messages survive reconnects.
+			go c.handleCallback(context.WithoutCancel(ctx), frame)
+		default:
+			// pong or other control frames — ignore
+		}
+	}
+}
+
+func (c *LongConnClient) authenticate(ctx context.Context) error {
+	authBody, _ := json.Marshal(map[string]string{
+		"bot_id": c.botID,
+		"secret": c.secret,
+	})
+
+	reqID := fmt.Sprintf("%s_%d", cmdSubscribe, time.Now().UnixNano())
+	frame := wsFrame{
+		Cmd:     cmdSubscribe,
+		Headers: map[string]string{"req_id": reqID},
+		Body:    authBody,
+	}
+
+	if err := c.writeJSON(frame); err != nil {
+		return fmt.Errorf("send subscribe: %w", err)
+	}
+
+	// Read auth response
+	c.mu.Lock()
+	conn := c.conn
+	c.mu.Unlock()
+	if conn == nil {
+		return fmt.Errorf("connection closed")
+	}
+
+	_ = conn.SetReadDeadline(time.Now().Add(10 * time.Second))
+	_, msg, err := conn.ReadMessage()
+	_ = conn.SetReadDeadline(time.Time{}) // clear deadline
+	if err != nil {
+		return fmt.Errorf("read auth response: %w", err)
+	}
+
+	var resp wsFrame
+	if err := json.Unmarshal(msg, &resp); err != nil {
+		return fmt.Errorf("unmarshal auth response: %w", err)
+	}
+
+	if resp.ErrCode != 0 {
+		return fmt.Errorf("auth failed: code=%d msg=%s", resp.ErrCode, resp.ErrMsg)
+	}
+
+	return nil
+}
+
+func (c *LongConnClient) heartbeatLoop(ctx context.Context) {
+	ticker := time.NewTicker(defaultHeartbeatInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			reqID := fmt.Sprintf("%s_%d", cmdPing, time.Now().UnixNano())
+			frame := wsFrame{
+				Cmd:     cmdPing,
+				Headers: map[string]string{"req_id": reqID},
+			}
+			if err := c.writeJSON(frame); err != nil {
+				logger.Warnf(ctx, "[WeCom] Heartbeat failed: %v", err)
+				return
+			}
+		}
+	}
+}
+
+func (c *LongConnClient) handleCallback(ctx context.Context, frame wsFrame) {
+	var msg botMessage
+	if err := json.Unmarshal(frame.Body, &msg); err != nil {
+		logger.Warnf(ctx, "[WeCom] Failed to unmarshal callback body: %v", err)
+		return
+	}
+
+	// Only handle text messages for now
+	if msg.MsgType != "text" {
+		logger.Infof(ctx, "[WeCom] Ignoring non-text message type: %s", msg.MsgType)
+		return
+	}
+
+	chatType := im.ChatTypeDirect
+	chatID := ""
+	if msg.ChatType == "group" {
+		chatType = im.ChatTypeGroup
+		chatID = msg.ChatID
+	}
+
+	// Preserve req_id in Extra for reply routing
+	reqID := ""
+	if frame.Headers != nil {
+		reqID = frame.Headers["req_id"]
+	}
+
+	incoming := &im.IncomingMessage{
+		Platform:  im.PlatformWeCom,
+		UserID:    msg.From.UserID,
+		UserName:  msg.From.UserID,
+		ChatID:    chatID,
+		ChatType:  chatType,
+		Content:   strings.TrimSpace(msg.Text.Content),
+		MessageID: msg.MsgID,
+		Extra:     map[string]string{"req_id": reqID},
+	}
+
+	if err := c.handler(ctx, incoming); err != nil {
+		logger.Errorf(ctx, "[WeCom] Handle message error: %v", err)
+	}
+}
+
+func (c *LongConnClient) writeJSON(v interface{}) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.conn == nil {
+		return fmt.Errorf("connection closed")
+	}
+	return c.conn.WriteJSON(v)
+}
+
+func reconnectDelay(attempt int) time.Duration {
+	delay := defaultReconnectBaseDelay * time.Duration(math.Pow(2, float64(attempt-1)))
+	if delay > defaultReconnectMaxDelay {
+		delay = defaultReconnectMaxDelay
+	}
+	return delay
+}
diff --git a/internal/router/router.go b/internal/router/router.go
index 1c98b2dec..77ef3f11b 100644
--- a/internal/router/router.go
+++ b/internal/router/router.go
@@ -59,6 +59,7 @@ type RouterParams struct {
 	CustomAgentHandler    *handler.CustomAgentHandler
 	SkillHandler          *handler.SkillHandler
 	OrganizationHandler   *handler.OrganizationHandler
+	IMHandler             *handler.IMHandler
 }
 
 // NewRouter 创建新的路由
@@ -103,6 +104,9 @@ func NewRouter(params RouterParams) *gin.Engine {
 		serveFrontendStatic(r)
 	}
 
+	// IM 回调路由（在认证中间件之前注册，使用各平台自身的签名验证）
+	RegisterIMRoutes(r, params.IMHandler)
+
 	// 认证中间件
 	r.Use(middleware.Auth(params.TenantService, params.UserService, params.Config))
 
@@ -576,6 +580,19 @@ func RegisterOrganizationRoutes(r *gin.RouterGroup, orgHandler *handler.Organiza
 	r.POST("/shared-agents/disabled", orgHandler.SetSharedAgentDisabledByMe)
 }
 
+// RegisterIMRoutes registers IM callback routes.
+// These are registered BEFORE auth middleware since IM platforms use their own signature verification.
+func RegisterIMRoutes(r *gin.Engine, imHandler *handler.IMHandler) {
+	im := r.Group("/api/v1/im")
+	{
+		// WeCom callback (supports both GET for URL verification and POST for message events)
+		im.GET("/callback/wecom", imHandler.WeComCallback)
+		im.POST("/callback/wecom", imHandler.WeComCallback)
+		// Feishu callback (POST for both URL verification challenge and message events)
+		im.POST("/callback/feishu", imHandler.FeishuCallback)
+	}
+}
+
 // serveFrontendStatic registers a middleware that serves the frontend SPA
 // from the ./web directory if it exists. Must be called BEFORE auth middleware
 // so static files are served without authentication.
diff --git a/migrations/versioned/000021_im_channel_sessions.down.sql b/migrations/versioned/000021_im_channel_sessions.down.sql
new file mode 100644
index 000000000..2ca2bfb6b
--- /dev/null
+++ b/migrations/versioned/000021_im_channel_sessions.down.sql
@@ -0,0 +1 @@
+DROP TABLE IF EXISTS im_channel_sessions;
diff --git a/migrations/versioned/000021_im_channel_sessions.up.sql b/migrations/versioned/000021_im_channel_sessions.up.sql
new file mode 100644
index 000000000..175d2d76e
--- /dev/null
+++ b/migrations/versioned/000021_im_channel_sessions.up.sql
@@ -0,0 +1,44 @@
+-- Migration: 000021_im_channel_sessions
+-- Description: Create IM channel-to-session mapping table
+DO $$ BEGIN RAISE NOTICE '[Migration 000021] Creating table: im_channel_sessions'; END $$;
+
+CREATE TABLE IF NOT EXISTS im_channel_sessions (
+    id VARCHAR(36) PRIMARY KEY DEFAULT uuid_generate_v4(),
+    platform VARCHAR(20) NOT NULL,
+    user_id VARCHAR(128) NOT NULL,
+    chat_id VARCHAR(128) NOT NULL DEFAULT '',
+    session_id VARCHAR(36) NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
+    tenant_id BIGINT NOT NULL,
+    agent_id VARCHAR(36) DEFAULT '',
+    status VARCHAR(20) NOT NULL DEFAULT 'active',
+    metadata JSONB DEFAULT '{}',
+    created_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    deleted_at TIMESTAMP WITH TIME ZONE
+);
+
+-- Partial unique index: only enforce uniqueness for non-deleted rows
+CREATE UNIQUE INDEX IF NOT EXISTS idx_channel_lookup
+    ON im_channel_sessions (platform, user_id, chat_id, tenant_id)
+    WHERE deleted_at IS NULL;
+
+-- Index for tenant-based queries
+CREATE INDEX IF NOT EXISTS idx_im_channel_tenant ON im_channel_sessions (tenant_id);
+
+-- Index for session-based queries
+CREATE INDEX IF NOT EXISTS idx_im_channel_session ON im_channel_sessions (session_id);
+
+-- Partial index for soft deletes (only index deleted rows)
+CREATE INDEX IF NOT EXISTS idx_im_channel_deleted ON im_channel_sessions (deleted_at) WHERE deleted_at IS NOT NULL;
+
+COMMENT ON TABLE im_channel_sessions IS 'Maps IM platform channels to WeKnora conversation sessions';
+COMMENT ON COLUMN im_channel_sessions.platform IS 'IM platform identifier: wecom, feishu, etc.';
+COMMENT ON COLUMN im_channel_sessions.user_id IS 'Platform-specific user identifier';
+COMMENT ON COLUMN im_channel_sessions.chat_id IS 'Platform-specific chat/group identifier, empty for direct messages';
+COMMENT ON COLUMN im_channel_sessions.session_id IS 'Associated WeKnora session ID';
+COMMENT ON COLUMN im_channel_sessions.tenant_id IS 'Tenant that owns this channel mapping';
+COMMENT ON COLUMN im_channel_sessions.agent_id IS 'Custom agent ID used for this channel, empty for default';
+COMMENT ON COLUMN im_channel_sessions.status IS 'Channel status: active, paused, expired';
+COMMENT ON COLUMN im_channel_sessions.metadata IS 'Platform-specific extra data (JSON)';
+
+DO $$ BEGIN RAISE NOTICE '[Migration 000021] im_channel_sessions setup completed successfully!'; END $$;