diff --git a/client/agent.go b/client/agent.go
index f3773ac2..18d2530b 100644
--- a/client/agent.go
+++ b/client/agent.go
@@ -33,6 +33,7 @@ type AgentQARequest struct {
 	DisableTitle     bool              `json:"disable_title,omitempty"`      // Whether to disable auto title generation
 	MCPServiceIDs    []string          `json:"mcp_service_ids,omitempty"`    // Optional MCP service allow list (deprecated)
 	Images           []ImageAttachment `json:"images,omitempty"`             // Attached images for multimodal chat
+	Channel          string            `json:"channel,omitempty"`            // Source channel: "web", "api", "im", etc.
 }
 
 // AgentResponseType defines the type of agent response
diff --git a/client/message.go b/client/message.go
index 95a51d8b..9eeda4fd 100644
--- a/client/message.go
+++ b/client/message.go
@@ -49,6 +49,7 @@ type Message struct {
 	KnowledgeReferences []*SearchResult `json:"knowledge_references"`
 	AgentSteps          []AgentStep     `json:"agent_steps,omitempty"` // Agent execution steps (only for assistant messages)
 	IsCompleted         bool            `json:"is_completed"`
+	Channel             string          `json:"channel,omitempty"` // Source channel: "web", "api", "im", etc.
 	CreatedAt           time.Time       `json:"created_at"`
 	UpdatedAt           time.Time       `json:"updated_at"`
 }
diff --git a/client/session.go b/client/session.go
index 831fc4c6..fa29a3d4 100644
--- a/client/session.go
+++ b/client/session.go
@@ -218,6 +218,7 @@ type KnowledgeQARequest struct {
 	SummaryModelID   string            `json:"summary_model_id"`   // Optional summary model ID (overrides session default)
 	DisableTitle     bool              `json:"disable_title"`      // Whether to disable auto title generation
 	Images           []ImageAttachment `json:"images,omitempty"`   // Attached images for multimodal chat
+	Channel          string            `json:"channel,omitempty"`  // Source channel: "web", "api", "im", etc.
 }
 
 // LLMToolCall represents a function/tool call from the LLM
diff --git a/frontend/src/api/chat/index.ts b/frontend/src/api/chat/index.ts
index 8b59875d..2b98c382 100644
--- a/frontend/src/api/chat/index.ts
+++ b/frontend/src/api/chat/index.ts
@@ -15,7 +15,7 @@ export async function generateSessionsTitle(session_id: string, data: any) {
 }
 
 export async function knowledgeChat(data: { session_id: string; query: string; }) {
-  return postChat(`/api/v1/knowledge-chat/${data.session_id}`, { query: data.query });
+  return postChat(`/api/v1/knowledge-chat/${data.session_id}`, { query: data.query, channel: "web" });
 }
 
 // Agent chat with streaming support
@@ -28,7 +28,8 @@ export async function agentChat(data: {
   return postChat(`/api/v1/agent-chat/${data.session_id}`, { 
     query: data.query,
     knowledge_base_ids: data.knowledge_base_ids,
-    agent_enabled: data.agent_enabled
+    agent_enabled: data.agent_enabled,
+    channel: "web"
   });
 }
 
diff --git a/frontend/src/api/chat/streame.ts b/frontend/src/api/chat/streame.ts
index f4f64439..ec789d92 100644
--- a/frontend/src/api/chat/streame.ts
+++ b/frontend/src/api/chat/streame.ts
@@ -118,6 +118,7 @@ export function useStream() {
       if (params.images !== undefined && params.images.length > 0) {
         postBody.images = params.images;
       }
+      postBody.channel = "web";
       
       await fetchEventSource(url, {
         method: params.method,
diff --git a/frontend/src/i18n/locales/en-US.ts b/frontend/src/i18n/locales/en-US.ts
index 51fd9afc..d033f359 100755
--- a/frontend/src/i18n/locales/en-US.ts
+++ b/frontend/src/i18n/locales/en-US.ts
@@ -1718,6 +1718,9 @@ export default {
     referencesDocAndWebCount: 'Referenced {docCount} document(s) and {webCount} web page(s)',
     referenceChunkCount: '{count} chunk(s)',
     fallbackHint: 'No relevant content found in knowledge base. Above is a direct response from the model.',
+    channelWeb: 'Web',
+    channelApi: 'API',
+    channelIm: 'IM',
     chunkLabel: 'Chunk {index}:',
     navigateToDocument: 'View document details',
     referenceIconAlt: 'Reference materials icon',
diff --git a/frontend/src/i18n/locales/ko-KR.ts b/frontend/src/i18n/locales/ko-KR.ts
index d1ba39ca..232cef4d 100755
--- a/frontend/src/i18n/locales/ko-KR.ts
+++ b/frontend/src/i18n/locales/ko-KR.ts
@@ -322,6 +322,9 @@ export default {
     referencesDocAndWebCount: "{docCount}개 문서와 {webCount}개 웹페이지 참조",
     referenceChunkCount: "{count}개 청크",
     fallbackHint: "지식 베이스에서 관련 내용을 찾지 못했습니다. 위는 모델의 직접 응답입니다.",
+    channelWeb: "웹",
+    channelApi: "API",
+    channelIm: "IM",
     chunkLabel: "청크 {index}:",
     navigateToDocument: "문서 상세 보기",
     referenceIconAlt: "참조 내용 아이콘",
diff --git a/frontend/src/i18n/locales/ru-RU.ts b/frontend/src/i18n/locales/ru-RU.ts
index 4be4f54e..9b70b050 100755
--- a/frontend/src/i18n/locales/ru-RU.ts
+++ b/frontend/src/i18n/locales/ru-RU.ts
@@ -1887,6 +1887,9 @@ export default {
     referencesDocAndWebCount: 'Использовано {docCount} документ(ов) и {webCount} веб-страниц(ы)',
     referenceChunkCount: '{count} фрагмент(ов)',
     fallbackHint: 'В базе знаний не найдено релевантного содержимого. Выше представлен прямой ответ модели.',
+    channelWeb: 'Веб',
+    channelApi: 'API',
+    channelIm: 'IM',
     chunkLabel: 'Фрагмент {index}:',
     navigateToDocument: 'Просмотр документа',
     referenceIconAlt: 'Иконка ссылок на материалы',
diff --git a/frontend/src/i18n/locales/zh-CN.ts b/frontend/src/i18n/locales/zh-CN.ts
index c9904f7d..7f064433 100755
--- a/frontend/src/i18n/locales/zh-CN.ts
+++ b/frontend/src/i18n/locales/zh-CN.ts
@@ -319,6 +319,9 @@ export default {
     referencesDocAndWebCount: "引用了{docCount}篇文档和{webCount}条网页",
     referenceChunkCount: "{count}个片段",
     fallbackHint: "未从知识库中检索到相关内容，以上为模型直接回答",
+    channelWeb: "网页",
+    channelApi: "API",
+    channelIm: "IM",
     chunkLabel: "片段{index}:",
     navigateToDocument: "查看文档详情",
     referenceIconAlt: "参考内容图标",
diff --git a/frontend/src/views/chat/components/usermsg.vue b/frontend/src/views/chat/components/usermsg.vue
index 85145190..8f406e2c 100644
--- a/frontend/src/views/chat/components/usermsg.vue
+++ b/frontend/src/views/chat/components/usermsg.vue
@@ -37,6 +37,9 @@
 import { defineProps, computed, ref, watch, onMounted, nextTick } from "vue";
 import { hydrateProtectedFileImages } from '@/utils/security';
 import picturePreview from '@/components/picture-preview.vue';
+import { useI18n } from 'vue-i18n';
+
+const { t } = useI18n();
 
 const props = defineProps({
     content: {
@@ -52,9 +55,28 @@ const props = defineProps({
         type: Array,
         required: false,
         default: () => []
+    },
+    channel: {
+        type: String,
+        required: false,
+        default: ''
     }
 });
 
+const channelLabelMap = {
+    web: () => t('chat.channelWeb'),
+    api: () => t('chat.channelApi'),
+    im: () => t('chat.channelIm'),
+};
+
+const channelLabel = computed(() => {
+    if (!props.channel) return '';
+    const label = channelLabelMap[props.channel];
+    return typeof label === 'function' ? label() : (label || props.channel);
+});
+
+const channelClass = computed(() => props.channel ? `channel-${props.channel}` : '');
+
 const containerRef = ref(null);
 const hasImages = computed(() => props.images && props.images.length > 0);
 
@@ -190,6 +212,37 @@ const closePreImg = () => {
     }
 }
 
+.channel_tag {
+    display: inline-flex;
+    align-items: center;
+    padding: 1px 6px;
+    border-radius: 3px;
+    font-size: 11px;
+    font-weight: 500;
+    line-height: 18px;
+    background: var(--td-bg-color-secondarycontainer);
+    color: var(--td-text-color-placeholder);
+    border: 1px solid var(--td-border-level-2-color, #e7e7e7);
+
+    &.channel-web {
+        color: var(--td-brand-color);
+        background: var(--td-brand-color-light);
+        border-color: var(--td-brand-color-2, rgba(0, 82, 217, 0.1));
+    }
+
+    &.channel-api {
+        color: var(--td-success-color);
+        background: var(--td-success-color-1, rgba(0, 168, 112, 0.06));
+        border-color: var(--td-success-color-2, rgba(0, 168, 112, 0.15));
+    }
+
+    &.channel-im {
+        color: var(--td-warning-color);
+        background: var(--td-warning-color-1, rgba(237, 123, 0, 0.06));
+        border-color: var(--td-warning-color-2, rgba(237, 123, 0, 0.15));
+    }
+}
+
 html[theme-mode="dark"] {
     .user_msg {
         background: var(--td-brand-color-3);
diff --git a/frontend/src/views/chat/index.vue b/frontend/src/views/chat/index.vue
index d7690859..2e648cbe 100644
--- a/frontend/src/views/chat/index.vue
+++ b/frontend/src/views/chat/index.vue
@@ -355,7 +355,7 @@ const sendMsg = async (value, modelId = '', mentionedItems = [], imageFiles = []
     }
 
     // 将@提及的知识库和文件信息存入用户消息
-    messagesList.push({ content: value, role: 'user', mentioned_items: mentionedItems, images: userImages });
+    messagesList.push({ content: value, role: 'user', mentioned_items: mentionedItems, images: userImages, channel: 'web' });
     scrollToBottom();
     
     // Get agent mode status from settings store
diff --git a/internal/handler/session/helpers.go b/internal/handler/session/helpers.go
index 32dcede2..d6acd02b 100644
--- a/internal/handler/session/helpers.go
+++ b/internal/handler/session/helpers.go
@@ -165,7 +165,7 @@ func createAgentQueryEvent(sessionID, assistantMessageID string) interfaces.Stre
 }
 
 // createUserMessage creates a user message and returns the created message.
-func (h *Handler) createUserMessage(ctx context.Context, sessionID, query, requestID string, mentionedItems types.MentionedItems, images types.MessageImages) (*types.Message, error) {
+func (h *Handler) createUserMessage(ctx context.Context, sessionID, query, requestID string, mentionedItems types.MentionedItems, images types.MessageImages, channel string) (*types.Message, error) {
 	return h.messageService.CreateMessage(ctx, &types.Message{
 		SessionID:      sessionID,
 		Role:           "user",
@@ -175,6 +175,7 @@ func (h *Handler) createUserMessage(ctx context.Context, sessionID, query, reque
 		IsCompleted:    true,
 		MentionedItems: mentionedItems,
 		Images:         images,
+		Channel:        channel,
 	})
 }
 
diff --git a/internal/handler/session/qa.go b/internal/handler/session/qa.go
index 0e5372ca..bcce1c79 100644
--- a/internal/handler/session/qa.go
+++ b/internal/handler/session/qa.go
@@ -36,6 +36,7 @@ type qaRequestContext struct {
 	effectiveTenantID uint64            // when using shared agent, tenant ID for model/KB/MCP resolution; 0 = use context tenant
 	images            []ImageAttachment // Uploaded images with analysis text
 	userMessageID     string            // Created user message ID (populated after createUserMessage)
+	channel           string            // Source channel: "web", "api", "im", etc.
 }
 
 // buildQARequest converts the qaRequestContext into a types.QARequest for service invocation.
@@ -148,6 +149,7 @@ func (h *Handler) parseQARequest(c *gin.Context, logPrefix string) (*qaRequestCo
 			Role:        "assistant",
 			RequestID:   c.GetString(types.RequestIDContextKey.String()),
 			IsCompleted: false,
+			Channel:     request.Channel,
 		},
 		knowledgeBaseIDs:  secutils.SanitizeForLogArray(kbIDs),
 		knowledgeIDs:      secutils.SanitizeForLogArray(knowledgeIDs),
@@ -157,6 +159,7 @@ func (h *Handler) parseQARequest(c *gin.Context, logPrefix string) (*qaRequestCo
 		mentionedItems:    convertMentionedItems(request.MentionedItems),
 		effectiveTenantID: effectiveTenantID,
 		images:            request.Images,
+		channel:           request.Channel,
 	}
 
 	return reqCtx, &request, nil
@@ -475,7 +478,7 @@ func (h *Handler) executeQA(reqCtx *qaRequestContext, mode qaMode, generateTitle
 	}
 
 	// Create user message
-	userMsg, err := h.createUserMessage(ctx, sessionID, reqCtx.query, reqCtx.requestID, reqCtx.mentionedItems, convertImageAttachments(reqCtx.images))
+	userMsg, err := h.createUserMessage(ctx, sessionID, reqCtx.query, reqCtx.requestID, reqCtx.mentionedItems, convertImageAttachments(reqCtx.images), reqCtx.channel)
 	if err != nil {
 		reqCtx.c.Error(errors.NewInternalServerError(err.Error()))
 		return
diff --git a/internal/handler/session/types.go b/internal/handler/session/types.go
index 235577ca..75f080bf 100644
--- a/internal/handler/session/types.go
+++ b/internal/handler/session/types.go
@@ -49,6 +49,7 @@ type CreateKnowledgeQARequest struct {
 	DisableTitle     bool                   `json:"disable_title"`                         // Whether to disable auto title generation
 	EnableMemory     bool                   `json:"enable_memory"`                         // Whether memory feature is enabled for this request
 	Images           []ImageAttachment      `json:"images"`                                // Attached images for multimodal chat
+	Channel          string                 `json:"channel"`                               // Source channel: "web", "api", "im", etc.
 }
 
 // SearchKnowledgeRequest defines the request structure for searching knowledge without LLM summarization
diff --git a/internal/im/service.go b/internal/im/service.go
index ac2c7b2e..6614d6e7 100644
--- a/internal/im/service.go
+++ b/internal/im/service.go
@@ -1424,6 +1424,7 @@ func (s *Service) handleMessageStream(ctx context.Context, msg *IncomingMessage,
 	userMsg, err := s.messageService.CreateMessage(qaCtx, &types.Message{
 		SessionID: session.ID, Role: "user", Content: msg.Content,
 		RequestID: requestID, CreatedAt: time.Now(), IsCompleted: true,
+		Channel: "im",
 	})
 	if err != nil {
 		return fmt.Errorf("create user message: %w", err)
@@ -1433,6 +1434,7 @@ func (s *Service) handleMessageStream(ctx context.Context, msg *IncomingMessage,
 	assistantMsg, err := s.messageService.CreateMessage(qaCtx, &types.Message{
 		SessionID: session.ID, Role: "assistant",
 		RequestID: requestID, CreatedAt: time.Now(), IsCompleted: false,
+		Channel: "im",
 	})
 	if err != nil {
 		return fmt.Errorf("create assistant message: %w", err)
@@ -1611,6 +1613,7 @@ func (s *Service) runQA(ctx context.Context, session *types.Session, query strin
 		RequestID:   requestID,
 		CreatedAt:   time.Now(),
 		IsCompleted: true,
+		Channel:     "im",
 	})
 	if err != nil {
 		return "", fmt.Errorf("create user message: %w", err)
@@ -1623,6 +1626,7 @@ func (s *Service) runQA(ctx context.Context, session *types.Session, query strin
 		RequestID:   requestID,
 		CreatedAt:   time.Now(),
 		IsCompleted: false,
+		Channel:     "im",
 	})
 	if err != nil {
 		return "", fmt.Errorf("create assistant message: %w", err)
diff --git a/internal/types/message.go b/internal/types/message.go
index 6624bbc2..ba452497 100644
--- a/internal/types/message.go
+++ b/internal/types/message.go
@@ -125,6 +125,8 @@ type Message struct {
 	IsFallback bool `json:"is_fallback,omitempty"`
 	// Agent total execution duration in milliseconds (from query start to answer start)
 	AgentDurationMs int64 `json:"agent_duration_ms,omitempty" gorm:"column:agent_duration_ms;default:0"`
+	// Channel indicates the source channel of this message (e.g., "web", "api", "im")
+	Channel string `json:"channel,omitempty" gorm:"type:varchar(50);default:''"`
 	// KnowledgeID links this message to a Knowledge entry in the chat history knowledge base
 	// Used for vector search indexing: when set, the message content has been indexed as a Knowledge passage
 	KnowledgeID string `json:"knowledge_id,omitempty" gorm:"type:varchar(36);index"`
diff --git a/migrations/sqlite/000000_init.up.sql b/migrations/sqlite/000000_init.up.sql
index 6b6f3312..4ce295bb 100644
--- a/migrations/sqlite/000000_init.up.sql
+++ b/migrations/sqlite/000000_init.up.sql
@@ -143,6 +143,7 @@ CREATE TABLE IF NOT EXISTS messages (
     mentioned_items TEXT DEFAULT '[]',
     is_completed BOOLEAN NOT NULL DEFAULT 0,
     is_fallback BOOLEAN NOT NULL DEFAULT 0,
+    channel VARCHAR(50) NOT NULL DEFAULT '',
     created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
     updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
     deleted_at DATETIME
diff --git a/migrations/versioned/000025_message_channel.down.sql b/migrations/versioned/000025_message_channel.down.sql
new file mode 100644
index 00000000..8c21a777
--- /dev/null
+++ b/migrations/versioned/000025_message_channel.down.sql
@@ -0,0 +1,3 @@
+-- Migration: 000025_message_channel (rollback)
+-- Description: Remove channel column from messages
+ALTER TABLE messages DROP COLUMN IF EXISTS channel;
diff --git a/migrations/versioned/000025_message_channel.up.sql b/migrations/versioned/000025_message_channel.up.sql
new file mode 100644
index 00000000..e3a8d62f
--- /dev/null
+++ b/migrations/versioned/000025_message_channel.up.sql
@@ -0,0 +1,9 @@
+-- Migration: 000025_message_channel
+-- Description: Add channel column to messages to track the source channel (web, api, im, etc.)
+DO $$ BEGIN RAISE NOTICE '[Migration 000025] Adding channel column to messages'; END $$;
+
+ALTER TABLE messages ADD COLUMN IF NOT EXISTS channel VARCHAR(50) NOT NULL DEFAULT '';
+
+COMMENT ON COLUMN messages.channel IS 'Source channel of the message: web, api, im, etc.';
+
+DO $$ BEGIN RAISE NOTICE '[Migration 000025] channel column added to messages successfully'; END $$;