diff --git a/backend/internal/handler/admin/channel_monitor_handler.go b/backend/internal/handler/admin/channel_monitor_handler.go
index e92c81fe..5560a513 100644
--- a/backend/internal/handler/admin/channel_monitor_handler.go
+++ b/backend/internal/handler/admin/channel_monitor_handler.go
@@ -38,6 +38,7 @@ func NewChannelMonitorHandler(monitorService *service.ChannelMonitorService) *Ch
 type channelMonitorCreateRequest struct {
 	Name             string            `json:"name" binding:"required,max=100"`
 	Provider         string            `json:"provider" binding:"required,oneof=openai anthropic gemini"`
+	APIMode          string            `json:"api_mode" binding:"omitempty,oneof=chat_completions responses"`
 	Endpoint         string            `json:"endpoint" binding:"required,max=500"`
 	APIKey           string            `json:"api_key" binding:"required,max=2000"`
 	PrimaryModel     string            `json:"primary_model" binding:"required,max=200"`
@@ -54,6 +55,7 @@ type channelMonitorCreateRequest struct {
 type channelMonitorUpdateRequest struct {
 	Name             *string            `json:"name" binding:"omitempty,max=100"`
 	Provider         *string            `json:"provider" binding:"omitempty,oneof=openai anthropic gemini"`
+	APIMode          *string            `json:"api_mode" binding:"omitempty,oneof=chat_completions responses"`
 	Endpoint         *string            `json:"endpoint" binding:"omitempty,max=500"`
 	APIKey           *string            `json:"api_key" binding:"omitempty,max=2000"`
 	PrimaryModel     *string            `json:"primary_model" binding:"omitempty,max=200"`
@@ -72,6 +74,7 @@ type channelMonitorResponse struct {
 	ID                  int64                                `json:"id"`
 	Name                string                               `json:"name"`
 	Provider            string                               `json:"provider"`
+	APIMode             string                               `json:"api_mode"`
 	Endpoint            string                               `json:"endpoint"`
 	APIKeyMasked        string                               `json:"api_key_masked"`
 	APIKeyDecryptFailed bool                                 `json:"api_key_decrypt_failed"`
@@ -138,6 +141,7 @@ func channelMonitorToResponse(m *service.ChannelMonitor) *channelMonitorResponse
 		ID:                  m.ID,
 		Name:                m.Name,
 		Provider:            m.Provider,
+		APIMode:             m.APIMode,
 		Endpoint:            m.Endpoint,
 		APIKeyMasked:        maskAPIKey(m.APIKey),
 		APIKeyDecryptFailed: m.APIKeyDecryptFailed,
@@ -303,6 +307,7 @@ func (h *ChannelMonitorHandler) Create(c *gin.Context) {
 	m, err := h.monitorService.Create(c.Request.Context(), service.ChannelMonitorCreateParams{
 		Name:             req.Name,
 		Provider:         req.Provider,
+		APIMode:          req.APIMode,
 		Endpoint:         req.Endpoint,
 		APIKey:           req.APIKey,
 		PrimaryModel:     req.PrimaryModel,
@@ -338,6 +343,7 @@ func (h *ChannelMonitorHandler) Update(c *gin.Context) {
 	m, err := h.monitorService.Update(c.Request.Context(), id, service.ChannelMonitorUpdateParams{
 		Name:             req.Name,
 		Provider:         req.Provider,
+		APIMode:          req.APIMode,
 		Endpoint:         req.Endpoint,
 		APIKey:           req.APIKey,
 		PrimaryModel:     req.PrimaryModel,
diff --git a/backend/internal/handler/admin/channel_monitor_template_handler.go b/backend/internal/handler/admin/channel_monitor_template_handler.go
index bebe0929..c842f465 100644
--- a/backend/internal/handler/admin/channel_monitor_template_handler.go
+++ b/backend/internal/handler/admin/channel_monitor_template_handler.go
@@ -27,6 +27,7 @@ func NewChannelMonitorRequestTemplateHandler(templateService *service.ChannelMon
 type channelMonitorTemplateCreateRequest struct {
 	Name             string            `json:"name" binding:"required,max=100"`
 	Provider         string            `json:"provider" binding:"required,oneof=openai anthropic gemini"`
+	APIMode          string            `json:"api_mode" binding:"omitempty,oneof=chat_completions responses"`
 	Description      string            `json:"description" binding:"max=500"`
 	ExtraHeaders     map[string]string `json:"extra_headers"`
 	BodyOverrideMode string            `json:"body_override_mode" binding:"omitempty,oneof=off merge replace"`
@@ -35,6 +36,7 @@ type channelMonitorTemplateCreateRequest struct {
 
 type channelMonitorTemplateUpdateRequest struct {
 	Name             *string            `json:"name" binding:"omitempty,max=100"`
+	APIMode          *string            `json:"api_mode" binding:"omitempty,oneof=chat_completions responses"`
 	Description      *string            `json:"description" binding:"omitempty,max=500"`
 	ExtraHeaders     *map[string]string `json:"extra_headers"`
 	BodyOverrideMode *string            `json:"body_override_mode" binding:"omitempty,oneof=off merge replace"`
@@ -45,6 +47,7 @@ type channelMonitorTemplateResponse struct {
 	ID                 int64             `json:"id"`
 	Name               string            `json:"name"`
 	Provider           string            `json:"provider"`
+	APIMode            string            `json:"api_mode"`
 	Description        string            `json:"description"`
 	ExtraHeaders       map[string]string `json:"extra_headers"`
 	BodyOverrideMode   string            `json:"body_override_mode"`
@@ -67,6 +70,7 @@ func (h *ChannelMonitorRequestTemplateHandler) toResponse(c *gin.Context, t *ser
 		ID:                 t.ID,
 		Name:               t.Name,
 		Provider:           t.Provider,
+		APIMode:            t.APIMode,
 		Description:        t.Description,
 		ExtraHeaders:       headers,
 		BodyOverrideMode:   t.BodyOverrideMode,
@@ -93,6 +97,7 @@ func parseTemplateID(c *gin.Context) (int64, bool) {
 func (h *ChannelMonitorRequestTemplateHandler) List(c *gin.Context) {
 	items, err := h.templateService.List(c.Request.Context(), service.ChannelMonitorRequestTemplateListParams{
 		Provider: strings.TrimSpace(c.Query("provider")),
+		APIMode:  strings.TrimSpace(c.Query("api_mode")),
 	})
 	if err != nil {
 		response.ErrorFrom(c, err)
@@ -129,6 +134,7 @@ func (h *ChannelMonitorRequestTemplateHandler) Create(c *gin.Context) {
 	t, err := h.templateService.Create(c.Request.Context(), service.ChannelMonitorRequestTemplateCreateParams{
 		Name:             req.Name,
 		Provider:         req.Provider,
+		APIMode:          req.APIMode,
 		Description:      req.Description,
 		ExtraHeaders:     req.ExtraHeaders,
 		BodyOverrideMode: req.BodyOverrideMode,
@@ -154,6 +160,7 @@ func (h *ChannelMonitorRequestTemplateHandler) Update(c *gin.Context) {
 	}
 	t, err := h.templateService.Update(c.Request.Context(), id, service.ChannelMonitorRequestTemplateUpdateParams{
 		Name:             req.Name,
+		APIMode:          req.APIMode,
 		Description:      req.Description,
 		ExtraHeaders:     req.ExtraHeaders,
 		BodyOverrideMode: req.BodyOverrideMode,
@@ -209,6 +216,7 @@ type associatedMonitorBriefResponse struct {
 	ID       int64  `json:"id"`
 	Name     string `json:"name"`
 	Provider string `json:"provider"`
+	APIMode  string `json:"api_mode"`
 	Enabled  bool   `json:"enabled"`
 }
 
@@ -227,7 +235,7 @@ func (h *ChannelMonitorRequestTemplateHandler) AssociatedMonitors(c *gin.Context
 	out := make([]associatedMonitorBriefResponse, 0, len(items))
 	for _, m := range items {
 		out = append(out, associatedMonitorBriefResponse{
-			ID: m.ID, Name: m.Name, Provider: m.Provider, Enabled: m.Enabled,
+			ID: m.ID, Name: m.Name, Provider: m.Provider, APIMode: m.APIMode, Enabled: m.Enabled,
 		})
 	}
 	response.Success(c, gin.H{"items": out})