diff --git a/.changeset/polite-eyes-invent.md b/.changeset/polite-eyes-invent.md
new file mode 100644
index 00000000..024c7b59
--- /dev/null
+++ b/.changeset/polite-eyes-invent.md
@@ -0,0 +1,5 @@
+---
+'svelte-migrate': minor
+---
+
+feat: add app-state migration
diff --git a/documentation/docs/20-commands/40-sv-migrate.md b/documentation/docs/20-commands/40-sv-migrate.md
index 570072b5..4c236462 100644
--- a/documentation/docs/20-commands/40-sv-migrate.md
+++ b/documentation/docs/20-commands/40-sv-migrate.md
@@ -14,6 +14,10 @@ npx sv migrate [migration]
## Migrations
+### `app-state`
+
+Migrates `$app/store` usage to `$app/state` in `.svelte` files. See the [migration guide](/docs/kit/migrating-to-sveltekit-2#SvelteKit-2.12:-$app-stores-deprecated) for more details.
+
### `svelte-5`
Upgrades a Svelte 4 app to use Svelte 5, and updates individual components to use [runes](../svelte/what-are-runes) and other Svelte 5 syntax ([see migration guide](../svelte/v5-migration-guide)).
diff --git a/packages/migrate/README.md b/packages/migrate/README.md
index c830db8c..07ae73a9 100644
--- a/packages/migrate/README.md
+++ b/packages/migrate/README.md
@@ -18,6 +18,7 @@ npx sv migrate [migration]
| Migration | From | To | Guide |
| ------------------- | --------------------- | --------------------- | --------------------------------------------------------------- |
+| `app-state` | `$app/stores` | `$app/state` | [#13140](https://github.com/sveltejs/kit/pull/13140) |
| `svelte-5` | Svelte 4 | Svelte 5 | [Website](https://svelte.dev/docs/svelte/v5-migration-guide) |
| `self-closing-tags` | Svelte 4 | Svelte 4 | [#12128](https://github.com/sveltejs/kit/pull/12128) |
| `svelte-4` | Svelte 3 | Svelte 4 | [Website](https://svelte.dev/docs/svelte/v4-migration-guide) |
diff --git a/packages/migrate/migrations/app-state/index.js b/packages/migrate/migrations/app-state/index.js
new file mode 100644
index 00000000..8ba9a326
--- /dev/null
+++ b/packages/migrate/migrations/app-state/index.js
@@ -0,0 +1,119 @@
+import colors from 'kleur';
+import fs from 'node:fs';
+import process from 'node:process';
+import prompts from 'prompts';
+import semver from 'semver';
+import glob from 'tiny-glob/sync.js';
+import { bail, check_git, update_svelte_file } from '../../utils.js';
+import { transform_svelte_code, update_pkg_json } from './migrate.js';
+
+export async function migrate() {
+ if (!fs.existsSync('package.json')) {
+ bail('Please re-run this script in a directory with a package.json');
+ }
+
+ const pkg = JSON.parse(fs.readFileSync('package.json', 'utf8'));
+
+ const svelte_dep = pkg.devDependencies?.svelte ?? pkg.dependencies?.svelte;
+ if (svelte_dep && semver.validRange(svelte_dep) && semver.gtr('5.0.0', svelte_dep)) {
+ console.log(
+ colors
+ .bold()
+ .red('\nYou need to upgrade to Svelte version 5 first (`npx sv migrate svelte-5`).\n')
+ );
+ process.exit(1);
+ }
+
+ const kit_dep = pkg.devDependencies?.['@sveltejs/kit'] ?? pkg.dependencies?.['@sveltejs/kit'];
+ if (kit_dep && semver.validRange(kit_dep) && semver.gtr('2.0.0', kit_dep)) {
+ console.log(
+ colors
+ .bold()
+ .red('\nYou need to upgrade to SvelteKit version 2 first (`npx sv migrate sveltekit-2`).\n')
+ );
+ process.exit(1);
+ }
+
+ console.log(
+ colors
+ .bold()
+ .yellow(
+ '\nThis will update files in the current directory\n' +
+ "If you're inside a monorepo, don't run this in the root directory, rather run it in all projects independently.\n"
+ )
+ );
+
+ const use_git = check_git();
+
+ const response = await prompts({
+ type: 'confirm',
+ name: 'value',
+ message: 'Continue?',
+ initial: false
+ });
+
+ if (!response.value) {
+ process.exit(1);
+ }
+
+ const folders = await prompts({
+ type: 'multiselect',
+ name: 'value',
+ message: 'Which folders should be migrated?',
+ choices: fs
+ .readdirSync('.')
+ .filter(
+ (dir) => fs.statSync(dir).isDirectory() && dir !== 'node_modules' && !dir.startsWith('.')
+ )
+ .map((dir) => ({ title: dir, value: dir, selected: true }))
+ });
+
+ if (!folders.value?.length) {
+ process.exit(1);
+ }
+
+ update_pkg_json();
+
+ // For some reason {folders.value.join(',')} as part of the glob doesn't work and returns less files
+ const files = folders.value.flatMap(
+ /** @param {string} folder */ (folder) =>
+ glob(`${folder}/**`, { filesOnly: true, dot: true })
+ .map((file) => file.replace(/\\/g, '/'))
+ .filter(
+ (file) =>
+ !file.includes('/node_modules/') &&
+ // We're not transforming usage inside .ts/.js files since you can't use the $store syntax there,
+ // and therefore have to either subscribe or pass it along, which we can't auto-migrate
+ file.endsWith('.svelte')
+ )
+ );
+
+ for (const file of files) {
+ update_svelte_file(
+ file,
+ (code) => code,
+ (code) => transform_svelte_code(code)
+ );
+ }
+
+ console.log(colors.bold().green('✔ Your project has been migrated'));
+
+ console.log('\nRecommended next steps:\n');
+
+ const cyan = colors.bold().cyan;
+
+ const tasks = [
+ "install the updated dependencies ('npm i' / 'pnpm i' / etc) " + use_git &&
+ cyan('git commit -m "migration to $app/state"')
+ ].filter(Boolean);
+
+ tasks.forEach((task, i) => {
+ console.log(` ${i + 1}: ${task}`);
+ });
+
+ console.log('');
+
+ if (use_git) {
+ console.log(`Run ${cyan('git diff')} to review changes.\n`);
+ }
+}
diff --git a/packages/migrate/migrations/app-state/migrate.js b/packages/migrate/migrations/app-state/migrate.js
new file mode 100644
index 00000000..43613663
--- /dev/null
+++ b/packages/migrate/migrations/app-state/migrate.js
@@ -0,0 +1,87 @@
+import fs from 'node:fs';
+import { update_pkg } from '../../utils.js';
+
+export function update_pkg_json() {
+ fs.writeFileSync(
+ 'package.json',
+ update_pkg_json_content(fs.readFileSync('package.json', 'utf8'))
+ );
+}
+
+/**
+ * @param {string} content
+ */
+export function update_pkg_json_content(content) {
+ return update_pkg(content, [['@sveltejs/kit', '^2.12.0']]);
+}
+
+/**
+ * @param {string} code
+ */
+export function transform_svelte_code(code) {
+ // Quick check if nothing to do
+ if (!code.includes('$app/stores')) return code;
+
+ // Check if file is using legacy APIs - if so, we can't migrate since reactive statements would break
+ const lines = code.split('\n');
+ if (lines.some((line) => /^\s*(export let|\$:) /.test(line))) {
+ return code;
+ }
+
+ const import_match = code.match(/import\s*{([^}]+)}\s*from\s*("|')\$app\/stores\2/);
+ if (!import_match) return code; // nothing to do
+
+ const stores = import_match[1].split(',').map((i) => {
+ const str = i.trim();
+ const [name, alias] = str.split(' as ').map((s) => s.trim());
+ return [name, alias || name];
+ });
+ let modified = code.replace('$app/stores', '$app/state');
+
+ let needs_navigating_migration_task = false;
+
+ for (const [store, alias] of stores) {
+ // if someone uses that they're deep into stores and we better not touch this file
+ if (store === 'getStores') return code;
+
+ const regex = new RegExp(`\\b${alias}\\b`, 'g');
+ let match;
+ let count_removed = 0;
+
+ while ((match = regex.exec(modified)) !== null) {
+ const before = modified.slice(0, match.index);
+ const after = modified.slice(match.index + alias.length);
+
+ if (before.slice(-1) !== '$') {
+ if (/[_'"]/.test(before.slice(-1))) continue; // false positive
+
+ if (store === 'updated' && after.startsWith('.check()')) {
+ continue; // this stays as is
+ }
+
+ if (
+ match.index - count_removed > /** @type {number} */ (import_match.index) &&
+ match.index - count_removed <
+ /** @type {number} */ (import_match.index) + import_match[0].length
+ ) {
+ continue; // this is the import statement
+ }
+
+ return code;
+ }
+
+ if (store === 'navigating' && after[0] !== '.') {
+ needs_navigating_migration_task = true;
+ }
+
+ modified = before.slice(0, -1) + alias + (store === 'updated' ? '.current' : '') + after;
+ count_removed++;
+ }
+ }
+
+ if (needs_navigating_migration_task) {
+ modified = `\n${modified}`;
+ }
+
+ return modified;
+}
diff --git a/packages/migrate/migrations/app-state/migrate.spec.js b/packages/migrate/migrations/app-state/migrate.spec.js
new file mode 100644
index 00000000..4162bddd
--- /dev/null
+++ b/packages/migrate/migrations/app-state/migrate.spec.js
@@ -0,0 +1,109 @@
+import { assert, test } from 'vitest';
+import { transform_svelte_code } from './migrate.js';
+
+test('Updates $app/store #1', () => {
+ const result = transform_svelte_code(
+ `
+
+{$page.url}
+
+`
+ );
+ assert.equal(
+ result,
+ `
+
+{page.url}
+
+`
+ );
+});
+
+test('Updates $app/store #2', () => {
+ const result = transform_svelte_code(
+ `
+
+{$navigating?.to?.url.pathname}
+`
+ );
+ assert.equal(
+ result,
+ `\n
+
+{navigating?.to?.url.pathname}
+`
+ );
+});
+
+test('Updates $app/store #3', () => {
+ const result = transform_svelte_code(
+ `
+
+{$_page.data}
+`
+ );
+ assert.equal(
+ result,
+ `
+
+{_page.data}
+`
+ );
+});
+
+test('Does not update $app/store #1', () => {
+ const input = `
+
+{x}
+`;
+ const result = transform_svelte_code(input);
+ assert.equal(result, input);
+});
+
+test('Does not update $app/store #2', () => {
+ const input = `
+
+{$url}
+`;
+ const result = transform_svelte_code(input);
+ assert.equal(result, input);
+});
+
+test('Does not update $app/store #3', () => {
+ const input = `
+
+{$page.url}
+`;
+ const result = transform_svelte_code(input);
+ assert.equal(result, input);
+});