diff --git a/packages/core/src/appdata.js b/packages/core/src/appdata.js
new file mode 100644
index 0000000..4e3ce6c
--- /dev/null
+++ b/packages/core/src/appdata.js
@@ -0,0 +1,24 @@
+import {homedir, platform} from 'os';
+import {join} from 'path';
+
+import mkdirp from 'mkdirp';
+
+export default (subdir) => {
+  let appdata;
+  switch (platform()) {
+    case 'windows':
+      appdata = '%APPDATA%';
+      break;
+    case 'darwin':
+      appdata = join(homedir(), 'Library/Application Support');
+      break;
+    default:
+      appdata = process.env.XDG_CONFIG_HOME || join(homedir(), '.config');
+      break;
+  }
+  if (subdir) {
+    appdata = join(appdata, subdir);
+  }
+  mkdirp.sync(appdata);
+  return appdata;
+};
diff --git a/packages/core/src/server.js b/packages/core/src/server.js
index 7d487fc..7c801cb 100644
--- a/packages/core/src/server.js
+++ b/packages/core/src/server.js
@@ -1,3 +1,5 @@
+export {default as appdata} from './appdata';
+
 export default {
   hooks: {
     '@latus/http/plugins': (req, {config: {'@latus/core': {id}}}) => ({