diff --git a/.changeset/fifty-seas-grab.md b/.changeset/fifty-seas-grab.md
new file mode 100644
index 0000000000..587ac5606d
--- /dev/null
+++ b/.changeset/fifty-seas-grab.md
@@ -0,0 +1,5 @@
+---
+'@backstage/frontend-app-api': minor
+---
+
+Updated core extension structure to make space for the sign-in page by adding `core.router`.
diff --git a/.changeset/hip-berries-begin.md b/.changeset/hip-berries-begin.md
new file mode 100644
index 0000000000..43d176cbcf
--- /dev/null
+++ b/.changeset/hip-berries-begin.md
@@ -0,0 +1,5 @@
+---
+'@backstage/frontend-test-utils': patch
+---
+
+Updates for `core.router` addition.
diff --git a/.changeset/nervous-dancers-wait.md b/.changeset/nervous-dancers-wait.md
new file mode 100644
index 0000000000..388d995487
--- /dev/null
+++ b/.changeset/nervous-dancers-wait.md
@@ -0,0 +1,5 @@
+---
+'@backstage/frontend-plugin-api': patch
+---
+
+Added `createSignInPageExtension`.