diff --git a/internal/server/server.go b/internal/server/server.go
index ebacb55..e763afe 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -491,12 +491,14 @@ func (s *Server) cardAction(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	// 回执消息：确认结论写进对话时间线（含所点按钮语义），审计锚点为 card.resolved 事件。
+	// 返回持久化后的回执消息（服务端 id），前端本地追加后与权威对账不重复。
+	var receipt *core.Message
 	if card.ConversationID != "" {
-		msg := core.Message{ID: store.NewID("msg"), ConversationID: card.ConversationID, Role: core.RoleAssistant, CreatedAt: time.Now().UTC()}
-		msg.Parts = []core.Part{{Type: core.PartText, Text: fmt.Sprintf("✓ 已按「%s」处理「%s」——结论已记录并留痕（card:%s）", label, card.Title, card.ID)}}
-		_ = s.st.AppendMessage(&msg)
+		receipt = &core.Message{ID: store.NewID("msg"), ConversationID: card.ConversationID, Role: core.RoleAssistant, CreatedAt: time.Now().UTC()}
+		receipt.Parts = []core.Part{{Type: core.PartText, Text: fmt.Sprintf("✓ 已按「%s」处理「%s」——结论已记录并留痕（card:%s）", label, card.Title, card.ID)}}
+		_ = s.st.AppendMessage(receipt)
 	}
-	writeJSON(w, http.StatusOK, map[string]any{"card": card})
+	writeJSON(w, http.StatusOK, map[string]any{"card": card, "receipt": receipt})
 }
 
 func (s *Server) cardPin(w http.ResponseWriter, r *http.Request) {