diff --git a/.changeset/deprecate-alert-api-core-app.md b/.changeset/deprecate-alert-api-core-app.md
new file mode 100644
index 0000000000..d25da2b8cf
--- /dev/null
+++ b/.changeset/deprecate-alert-api-core-app.md
@@ -0,0 +1,5 @@
+---
+'@backstage/core-app-api': patch
+---
+
+Deprecated `AlertApiForwarder` in favor of the new `ToastApi`. The `AlertApiForwarder` now emits a console warning on first use, guiding developers to migrate to `ToastApi` from `@backstage/frontend-plugin-api`.
diff --git a/.changeset/deprecate-alert-api-core-plugin.md b/.changeset/deprecate-alert-api-core-plugin.md
new file mode 100644
index 0000000000..809652a84c
--- /dev/null
+++ b/.changeset/deprecate-alert-api-core-plugin.md
@@ -0,0 +1,5 @@
+---
+'@backstage/core-plugin-api': patch
+---
+
+Deprecated `AlertApi`, `AlertMessage`, and `alertApiRef` in favor of the new `ToastApi` from `@backstage/frontend-plugin-api`.
diff --git a/packages/frontend-defaults/src/createApp.test.tsx b/packages/frontend-defaults/src/createApp.test.tsx
index d0817d6428..832dd1b0d3 100644
--- a/packages/frontend-defaults/src/createApp.test.tsx
+++ b/packages/frontend-defaults/src/createApp.test.tsx
@@ -357,6 +357,7 @@ describe('createApp', () => {
           <api:app/dialog out=[core.api.factory] />
           <api:app/discovery out=[core.api.factory] />
           <api:app/alert out=[core.api.factory] />
+          <api:app/toast-forwarder out=[core.api.factory] />
           <api:app/toast out=[core.api.factory] />
           <api:app/analytics out=[core.api.factory] />
           <api:app/error out=[core.api.factory] />