diff --git a/package.json b/package.json
index 8722edf..d508050 100644
--- a/package.json
+++ b/package.json
@@ -11,6 +11,7 @@
     "dev": "rollup -c --configPlugin=swc3 -w",
     "build": "rollup -c --configPlugin=swc3",
     "lint": "tsc -p . --noEmit && svelte-check",
+    "fmt": "prettier --plugin-search-dir=. --write .",
     "test": "jest"
   },
   "devDependencies": {
@@ -29,6 +30,8 @@
     "@types/testing-library__jest-dom": "^5.14.5",
     "fast-glob": "^3.2.12",
     "jest": "^26.4.2",
+    "prettier": "^2.8.3",
+    "prettier-plugin-svelte": "^2.9.0",
     "rollup": "^3.10.1",
     "rollup-plugin-svelte": "^7.1.0",
     "rollup-plugin-swc3": "^0.8.0",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 9fd5bcb..85a5f63 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -19,6 +19,8 @@ importers:
       '@types/testing-library__jest-dom': ^5.14.5
       fast-glob: ^3.2.12
       jest: ^26.4.2
+      prettier: ^2.8.3
+      prettier-plugin-svelte: ^2.9.0
       rollup: ^3.10.1
       rollup-plugin-svelte: ^7.1.0
       rollup-plugin-swc3: ^0.8.0
@@ -44,6 +46,8 @@ importers:
       '@types/testing-library__jest-dom': 5.14.5
       fast-glob: 3.2.12
       jest: 26.6.3
+      prettier: 2.8.3
+      prettier-plugin-svelte: 2.9.0_kdmmghgdi3ngrsq6otxkjilbry
       rollup: 3.10.1
       rollup-plugin-svelte: 7.1.0_qpm4c73r2qbttfqo5sbvfs5qda
       rollup-plugin-swc3: 0.8.0_2czi33u7rp44ncw5lbqb7p7c5i
@@ -3807,6 +3811,22 @@ packages:
     engines: {node: '>= 0.8.0'}
     dev: true
 
+  /prettier-plugin-svelte/2.9.0_kdmmghgdi3ngrsq6otxkjilbry:
+    resolution: {integrity: sha512-3doBi5NO4IVgaNPtwewvrgPpqAcvNv0NwJNflr76PIGgi9nf1oguQV1Hpdm9TI2ALIQVn/9iIwLpBO5UcD2Jiw==}
+    peerDependencies:
+      prettier: ^1.16.4 || ^2.0.0
+      svelte: ^3.2.0
+    dependencies:
+      prettier: 2.8.3
+      svelte: 3.55.1
+    dev: true
+
+  /prettier/2.8.3:
+    resolution: {integrity: sha512-tJ/oJ4amDihPoufT5sM0Z1SKEuKay8LfVAMlbbhnnkvt6BUserZylqo2PN+p9KeljLr0OHa2rXHU1T8reeoTrw==}
+    engines: {node: '>=10.13.0'}
+    hasBin: true
+    dev: true
+
   /pretty-format/26.6.2:
     resolution: {integrity: sha512-7AeGuCYNGmycyQbCqd/3PWH4eOoX/OiCa0uphp57NVTeAGdJGaAliecxwBDHYQCIvrW7aDBZCYeNTP/WX69mkg==}
     engines: {node: '>= 10'}