From 8cc227c4ad187a972e53be48afb169a2d9989184 Mon Sep 17 00:00:00 2001
From: Victor Chu <victor.chu@shopify.com>
Date: Mon, 17 Aug 2026 16:29:21 -0700
Subject: [PATCH 1/2] fix: restore calver package versions on 2026-10-rc

Assisted-By: devx/60256637-da58-4f80-9e3a-977e038d8a71
---
 packages/ui-extensions-tester/CHANGELOG.md           |  4 ++--
 packages/ui-extensions-tester/package.json           |  4 ++--
 .../src/tests/api-version.test.ts                    | 12 ++++++++++++
 packages/ui-extensions/CHANGELOG.md                  |  2 +-
 packages/ui-extensions/package.json                  |  2 +-
 5 files changed, 18 insertions(+), 6 deletions(-)
 create mode 100644 packages/ui-extensions-tester/src/tests/api-version.test.ts

diff --git a/packages/ui-extensions-tester/CHANGELOG.md b/packages/ui-extensions-tester/CHANGELOG.md
index 528467b02a..fd07785315 100644
--- a/packages/ui-extensions-tester/CHANGELOG.md
+++ b/packages/ui-extensions-tester/CHANGELOG.md
@@ -1,6 +1,6 @@
 # @shopify/ui-extensions-tester
 
-## 2027.0.0-rc.5
+## 2026.10.0-rc.5
 
 ### Major Changes
 
@@ -13,7 +13,7 @@
 ### Patch Changes
 
 - Updated dependencies [[`d8b03c9`](https://github.com/Shopify/ui-extensions/commit/d8b03c99ac71e227d55743a5da657b94575e31b7), [`8e59844`](https://github.com/Shopify/ui-extensions/commit/8e59844f885f3df4e409964b5df370e5a58c7f21)]:
-  - @shopify/ui-extensions@2027.0.0-rc.5
+  - @shopify/ui-extensions@2026.10.0-rc.5
 
 ## 2026.10.0-rc.4
 
diff --git a/packages/ui-extensions-tester/package.json b/packages/ui-extensions-tester/package.json
index 933298a8f0..44090743af 100644
--- a/packages/ui-extensions-tester/package.json
+++ b/packages/ui-extensions-tester/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@shopify/ui-extensions-tester",
-  "version": "2027.0.0-rc.5",
+  "version": "2026.10.0-rc.5",
   "main": "index.js",
   "module": "index.mjs",
   "esnext": "index.esnext",
@@ -55,7 +55,7 @@
   },
   "license": "MIT",
   "dependencies": {
-    "@shopify/ui-extensions": "2027.0.0-rc.5"
+    "@shopify/ui-extensions": "2026.10.0-rc.5"
   },
   "peerDependencies": {
     "preact": "^10.0.0"
diff --git a/packages/ui-extensions-tester/src/tests/api-version.test.ts b/packages/ui-extensions-tester/src/tests/api-version.test.ts
new file mode 100644
index 0000000000..66a2d24041
--- /dev/null
+++ b/packages/ui-extensions-tester/src/tests/api-version.test.ts
@@ -0,0 +1,12 @@
+import {API_VERSION} from '../api-version';
+
+describe('API_VERSION', () => {
+  // API_VERSION derives from the npm package version (2026.10.x -> "2026-10"),
+  // so a semver-major changeset on this calver-keyed package rolls the year and
+  // produces a nonexistent API version ("2027-00"), breaking every consumer
+  // pinned to the branch's real version. Breaking changes here must be
+  // released as minor bumps within the branch's calendar version.
+  it('is a quarterly Shopify API version', () => {
+    expect(API_VERSION).toMatch(/^\d{4}-(01|04|07|10)$/);
+  });
+});
diff --git a/packages/ui-extensions/CHANGELOG.md b/packages/ui-extensions/CHANGELOG.md
index 38c20b3107..195b14fa74 100644
--- a/packages/ui-extensions/CHANGELOG.md
+++ b/packages/ui-extensions/CHANGELOG.md
@@ -1,6 +1,6 @@
 # @shopify/ui-extensions
 
-## 2027.0.0-rc.5
+## 2026.10.0-rc.5
 
 ### Major Changes
 
diff --git a/packages/ui-extensions/package.json b/packages/ui-extensions/package.json
index 0f3eea0e25..790ea269aa 100644
--- a/packages/ui-extensions/package.json
+++ b/packages/ui-extensions/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@shopify/ui-extensions",
-  "version": "2027.0.0-rc.5",
+  "version": "2026.10.0-rc.5",
   "scripts": {
     "docs:admin": "node ./docs/surfaces/admin/build-docs.mjs",
     "docs:checkout": "bash ./docs/surfaces/checkout/build-docs.sh",

From 709c48dde13ade1d3da7eacbc1dfef91eba18de5 Mon Sep 17 00:00:00 2001
From: Victor Chu <victor.chu@shopify.com>
Date: Mon, 17 Aug 2026 16:35:36 -0700
Subject: [PATCH 2/2] fix: downgrade retained pre-mode changeset to minor

Assisted-By: devx/60256637-da58-4f80-9e3a-977e038d8a71
---
 .changeset/pos-remove-action-api-from-action-render.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.changeset/pos-remove-action-api-from-action-render.md b/.changeset/pos-remove-action-api-from-action-render.md
index e1dcab2f69..8212a0a340 100644
--- a/.changeset/pos-remove-action-api-from-action-render.md
+++ b/.changeset/pos-remove-action-api-from-action-render.md
@@ -1,6 +1,6 @@
 ---
-'@shopify/ui-extensions': major
-'@shopify/ui-extensions-tester': major
+'@shopify/ui-extensions': minor
+'@shopify/ui-extensions-tester': minor
 ---
 
 Remove the POS Action API (`shopify.action.presentModal()`) from action render targets (`*.action.render`).