Unicorn supports Django messages and they work the same as if the template was rendered server-side. When the update action is fired, a success message will be added to the request and will show up inside the component.

<!-- messages.html -->
    {% if messages %}
    <ul class="messages">
        {% for message in messages %}
        <li{% if message.tags %} class="{{ message.tags }}"{% endif %}>{{ message }}</li>
        {% endfor %}
    {% endif %}

    <button unicorn:click="update">Update</button>
from django.contrib import messages
from django_unicorn.components import UnicornView

class MessagesView(UnicornView):
    def update(self):
        messages.success(self.request, "update called")