diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index cc9a20c0..8df1c23e 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -11,7 +11,7 @@
   "mounts": [
     "source=${localWorkspaceFolderBasename}-node_modules,target=${containerWorkspaceFolder}/node_modules,type=volume"
   ],
-  "postCreateCommand": "sudo chown node:node node_modules",
+  "postCreateCommand": "sudo chown node:node node_modules && npm install -g npm@11",
   "containerEnv": {
     "CI": "true"
   },
diff --git a/.gitignore b/.gitignore
index 52a6fb1a..f17f60fb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,3 +23,4 @@ yarn-debug.log*
 yarn-error.log*
 .vercel
 .idea
+.claude/settings.local.json
diff --git a/package-lock.json b/package-lock.json
index 8fa8f98f..5716b99f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -41,7 +41,8 @@
         "typescript-eslint": "^8.53.0"
       },
       "engines": {
-        "node": "24"
+        "node": "24",
+        "npm": "^11.7.0"
       }
     },
     "node_modules/@ai-sdk/gateway": {
diff --git a/package.json b/package.json
index 21001265..fee2d81a 100644
--- a/package.json
+++ b/package.json
@@ -67,6 +67,7 @@
     ]
   },
   "engines": {
-    "node": "24"
+    "node": "24",
+    "npm": "^11.7.0"
   }
 }