docs: add cloud shutdown doc

Author: acco

docs/shutdown.mdx

@@ -0,0 +1,71 @@
+---
+title: Sequin Cloud shutdown
+description: Important information about the Sequin Cloud shutdown and migration to self-hosting.
+---
+
+**Sequin Cloud has been acquired and will be shutting down on October 23, 2025**.
+
+We know this creates disruption, and we want to make the transition as smooth as possible. Since Sequin is fully open-source under the MIT license, we're committed to helping you migrate to a self-hosted deployment.
+
+In the near term, the core Sequin team's input to the open-source project will scale down to maintenance mode. We'll continue prioritizing security patches and critical bug fixes, though new feature development will slow significantly. Looking ahead, we're excited about the potential for renewed investment in the project inside the acquiring company, though the timeline isn't set and may extend into 2026.
+
+## What's happening
+
+- **Today (August 21, 2025)**: We're announcing the shutdown. All Cloud subscriptions will be automatically canceled and we'll issue refunds for unused months if you are on an annual plan.
+- **Over the next 60 days**: Sequin Cloud services will continue to run as you migrate to self-hosting or another solution.
+- **October 23, 2025**: Sequin Cloud will be turned off, pipelines will stop, and all hosted data will be permanently and securely deleted.
+
+## Migration options
+
+### Self-hosting Sequin (Recommended)
+
+Since Sequin is open-source, you can run it on your own infrastructure with full feature parity to the cloud version. We have comprehensive guides to help you get started:
+
+- **[Running Sequin](/running-sequin)** - Overview of deployment options
+- **[Deploy to Production](/how-to/deploy-to-production)** - Production deployment guide
+- **[Helm Chart](github.com/sequinstream/helm-chart-sequin)** - Helm chart
+- **[sequin.yaml](/docs/reference/sequin-yaml)** - Configuration file reference for exporting and importing data
+
+### Migration support
+
+We're committed to making this transition smooth:
+
+- **Migration and deployment assistance**: We'll help you stand up your own deployment
+- **Technical support**: Direct access to our engineering team during the transition
+
+## Getting help
+
+We're available to answer questions and provide hands-on migration support:
+
+- Email us at **support@sequinstream.com**
+- Join our [Discord community](https://discord.gg/BV8wFXvNtY)
+- Join our [Slack community](https://join.slack.com/t/sequin-community/shared_invite/zt-37begzach-4aUwR5xt_XgivdvctZDemA)
+- Schedule a migration consultation call
+
+## Timeline
+
+| Date | Milestone |
+|------|-----------|
+| Today (August 21, 2025) | Shutdown announcement, subscriptions canceled |
+| Next 60 days | Cloud services continue running, migration period |
+| October 23, 2025 | Sequin Cloud shutdown, all data deleted |
+
+## Frequently asked questions
+
+**Will my self-hosted deployment have the same features as the cloud version?**
+
+Yes, Sequin is fully open-source with no feature limitations. You'll have access to all the same capabilities.
+
+**Can I export my current configuration?**
+
+Absolutely. You can use [sequin.yaml](/docs/reference/sequin-yaml) to export your configuration.
+
+**Will you help with the migration?**
+
+Yes, we're committed to helping every user successfully migrate. We'll provide hands-on assistance to ensure your deployment is running smoothly.
+
+**What happens to the open-source project after the Cloud shutdown?**
+
+The open-source project will continue in maintenance mode with security patches and critical bug fixes. New feature development will slow as the team has been acquired. However, we're excited about the future of the project, as there's potential for renewed investment inside the acquiring company.
+
+We apologize for the inconvenience this creates and are dedicated to ensuring a smooth transition. Thank you for using Sequin.

lib/sequin_web/components/layouts.ex

@@ -23,19 +23,29 @@ defmodule SequinWeb.Layouts do
   def app_no_sidenav(assigns) do
     assigns = assign(assigns, :show_nav, false)
 
-    app(assigns)
+    assigns
+    |> put_common_assigns()
+    |> app()
   end
 
   def app_no_main(assigns) do
     assigns = assign(assigns, :no_main, true)
 
-    app(assigns)
+    assigns
+    |> put_common_assigns()
+    |> app()
   end
 
   def app_no_main_no_sidenav(assigns) do
     assigns = assign(assigns, :show_nav, false)
     assigns = assign(assigns, :no_main, true)
 
-    app(assigns)
+    assigns
+    |> put_common_assigns()
+    |> app()
+  end
+
+  defp put_common_assigns(assigns) do
+    assign(assigns, :self_hosted, Application.fetch_env!(:sequin, :self_hosted))
   end
 end

lib/sequin_web/components/layouts/app.html.heex

@@ -1,3 +1,11 @@
+<%= if Map.get(assigns, :self_hosted, false) == false do %>
+  <div class="bg-amber-400 text-black px-4 py-2 text-center text-sm">
+    Sequin Cloud is shutting down on October 23, 2025. <a
+      href="https://sequinstream.com/docs/shutdown"
+      class="underline hover:no-underline"
+    >Learn more</a>.
+  </div>
+<% end %>
 <div class="flex min-h-screen">
   <%= if @show_nav do %>
     <.live_component