diff --git a/common/package.json b/common/package.json
new file mode 100644
index 00000000..68e7a56b
--- /dev/null
+++ b/common/package.json
@@ -0,0 +1,12 @@
+{
+    "name": "dwengo-1-common",
+    "version": "0.1.1",
+    "description": "Common types and utilities for Dwengo-1",
+    "private": true,
+    "type": "module",
+    "scripts": {
+        "format": "prettier --write src/",
+        "format-check": "prettier --check src/",
+        "lint": "eslint . --fix"
+    }
+}
diff --git a/common/tsconfig.json b/common/tsconfig.json
new file mode 100644
index 00000000..2dd3998d
--- /dev/null
+++ b/common/tsconfig.json
@@ -0,0 +1,9 @@
+{
+    "extends": "../tsconfig.json",
+    "include": ["src/**/*.ts"],
+    "compilerOptions": {
+        "rootDir": "./src",
+        "outDir": "./dist",
+        "resolveJsonModule": true
+    }
+}
diff --git a/package-lock.json b/package-lock.json
index c54f2f5f..863bd035 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,6 +10,7 @@
             "license": "MIT",
             "workspaces": [
                 "backend",
+                "common",
                 "frontend",
                 "docs"
             ],
@@ -81,6 +82,10 @@
                 "url": "https://github.com/sponsors/sindresorhus"
             }
         },
+        "common": {
+            "name": "dwengo-1-common",
+            "version": "0.1.1"
+        },
         "docs": {
             "name": "dwengo-1-docs",
             "version": "0.0.1",
@@ -4011,6 +4016,10 @@
             "resolved": "backend",
             "link": true
         },
+        "node_modules/dwengo-1-common": {
+            "resolved": "common",
+            "link": true
+        },
         "node_modules/dwengo-1-docs": {
             "resolved": "docs",
             "link": true
diff --git a/package.json b/package.json
index 7adeb3aa..56e3d01c 100644
--- a/package.json
+++ b/package.json
@@ -5,14 +5,15 @@
     "private": true,
     "type": "module",
     "scripts": {
-        "build": "npm run build --ws",
-        "format": "npm run format --ws",
-        "format-check": "npm run format-check --ws",
-        "lint": "npm run lint --ws",
-        "test:unit": "npm run test:unit --ws"
+        "build": "npm run build --workspace=backend --workspace=frontend",
+        "format": "npm run format --workspace=backend --workspace=common --workspace=frontend",
+        "format-check": "npm run format-check --workspace=backend --workspace=common --workspace=frontend",
+        "lint": "npm run lint --workspace=backend --workspace=common --workspace=frontend",
+        "test:unit": "npm run test:unit --workspace=backend --workspace=frontend"
     },
     "workspaces": [
         "backend",
+        "common",
         "frontend",
         "docs"
     ],