diff --git a/.env.example b/.env.example
index 9cabbc6f..21cb8624 100644
--- a/.env.example
+++ b/.env.example
@@ -1,2 +1,3 @@
 # replace ghp_example with your GitHub PAT token
 TOKEN=ghp_example
+WHITELIST=shinokada
\ No newline at end of file
diff --git a/.vercelignore b/.vercelignore
new file mode 100644
index 00000000..b8497ff3
--- /dev/null
+++ b/.vercelignore
@@ -0,0 +1,14 @@
+tests/
+.git/
+.github/
+.devcontainer/
+node_modules/
+*.md
+!README.md
+.editorconfig
+.prettierrc.js
+.prettierignore
+.deepsource.toml
+phpunit.xml
+Dockerfile
+Procfile
diff --git a/api/index.php b/api/index.php
new file mode 100644
index 00000000..9551b32f
--- /dev/null
+++ b/api/index.php
@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+
+// Load functions with absolute paths for Vercel
+require_once __DIR__ . "/../vendor/autoload.php";
+require_once __DIR__ . "/../src/stats.php";
+require_once __DIR__ . "/../src/card.php";
+
+// Load .env
+$dotenv = \Dotenv\Dotenv::createImmutable(__DIR__ . "/..");
+$dotenv->safeLoad();
+
+// If environment variables are not loaded, display error
+if (!isset($_SERVER["TOKEN"]) && !isset($_ENV["TOKEN"])) {
+    $message = "Missing TOKEN environment variable. Please set it in Vercel project settings.";
+    renderOutput($message, 500);
+    exit();
+}
+
+// Use environment variable if not in $_SERVER
+if (!isset($_SERVER["TOKEN"]) && isset($_ENV["TOKEN"])) {
+    $_SERVER["TOKEN"] = $_ENV["TOKEN"];
+}
+
+// Set cache to refresh once per three hours
+$cacheMinutes = 3 * 60 * 60;
+header("Expires: " . gmdate("D, d M Y H:i:s", time() + $cacheMinutes) . " GMT");
+header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
+header("Cache-Control: public, max-age=$cacheMinutes");
+
+// Redirect to demo site if user is not given
+if (!isset($_REQUEST["user"])) {
+    header("Location: /demo/");
+    exit();
+}
+
+try {
+    // Get streak stats for user given in query string
+    $user = preg_replace("/[^a-zA-Z0-9\-]/", "", $_REQUEST["user"]);
+    $startingYear = isset($_REQUEST["starting_year"]) ? intval($_REQUEST["starting_year"]) : null;
+    $contributionGraphs = getContributionGraphs($user, $startingYear);
+    $contributions = getContributionDates($contributionGraphs);
+    if (isset($_GET["mode"]) && $_GET["mode"] === "weekly") {
+        $stats = getWeeklyContributionStats($contributions);
+    } else {
+        // Split and normalize excluded days
+        $excludeDays = normalizeDays(explode(",", $_GET["exclude_days"] ?? ""));
+        $stats = getContributionStats($contributions, $excludeDays);
+    }
+    renderOutput($stats);
+} catch (InvalidArgumentException | AssertionError $error) {
+    error_log("Error {$error->getCode()}: {$error->getMessage()}");
+    if ($error->getCode() >= 500) {
+        renderOutput("Unable to fetch contribution data. Please try again later.", 500);
+    } else {
+        renderOutput($error->getMessage(), $error->getCode());
+    }
+} catch (Exception $error) {
+    error_log("Unexpected error: " . $error->getMessage());
+    renderOutput("An unexpected error occurred. Please try again later.", 500);
+}
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
new file mode 100644
index 00000000..360dd30b
--- /dev/null
+++ b/pnpm-lock.yaml
@@ -0,0 +1,48 @@
+lockfileVersion: '9.0'
+
+settings:
+  autoInstallPeers: true
+  excludeLinksFromLockfile: false
+
+importers:
+
+  .:
+    devDependencies:
+      '@prettier/plugin-php':
+        specifier: ^0.24.0
+        version: 0.24.0(prettier@3.7.4)
+      prettier:
+        specifier: ^3.6.2
+        version: 3.7.4
+
+packages:
+
+  '@prettier/plugin-php@0.24.0':
+    resolution: {integrity: sha512-x9l65fCE/pgoET6RQowgdgG8Xmzs44z6j6Hhg3coINCyCw9JBGJ5ZzMR2XHAM2jmAdbJAIgqB6cUn4/3W3XLTA==}
+    peerDependencies:
+      prettier: ^3.0.0
+
+  linguist-languages@8.2.0:
+    resolution: {integrity: sha512-KCUUH9x97QWYU0SXOCGxUrZR6cSfuQrMhABB7L/0I8N0LXOeaKe7+RZs7FAwvWCV2qKfZ4Wv1luLq4OfMezSJg==}
+
+  php-parser@3.2.5:
+    resolution: {integrity: sha512-M1ZYlALFFnESbSdmRtTQrBFUHSriHgPhgqtTF/LCbZM4h7swR5PHtUceB2Kzby5CfqcsYwBn7OXTJ0+8Sajwkw==}
+
+  prettier@3.7.4:
+    resolution: {integrity: sha512-v6UNi1+3hSlVvv8fSaoUbggEM5VErKmmpGA7Pl3HF8V6uKY7rvClBOJlH6yNwQtfTueNkGVpOv/mtWL9L4bgRA==}
+    engines: {node: '>=14'}
+    hasBin: true
+
+snapshots:
+
+  '@prettier/plugin-php@0.24.0(prettier@3.7.4)':
+    dependencies:
+      linguist-languages: 8.2.0
+      php-parser: 3.2.5
+      prettier: 3.7.4
+
+  linguist-languages@8.2.0: {}
+
+  php-parser@3.2.5: {}
+
+  prettier@3.7.4: {}
diff --git a/src/whitelist.php b/src/whitelist.php
index 21114834..26731476 100644
--- a/src/whitelist.php
+++ b/src/whitelist.php
@@ -8,6 +8,7 @@
  */
 function isWhitelisted(string $user): bool
 {
-    $whitelist = array_map("trim", array_filter(explode(",", $_SERVER["WHITELIST"] ?? "")));
+    $whitelistStr = $_SERVER["WHITELIST"] ?? $_ENV["WHITELIST"] ?? getenv("WHITELIST") ?? "";
+    $whitelist = array_map("trim", array_filter(explode(",", $whitelistStr)));
     return empty($whitelist) || in_array($user, $whitelist, true);
 }
diff --git a/vercel.json b/vercel.json
new file mode 100644
index 00000000..5b25e87c
--- /dev/null
+++ b/vercel.json
@@ -0,0 +1,23 @@
+{
+  "version": 2,
+  "functions": {
+    "api/*.php": {
+      "runtime": "vercel-php@0.7.1"
+    }
+  },
+  "routes": [
+    {
+      "src": "/demo/(.*)",
+      "dest": "/src/demo/$1"
+    },
+    {
+      "src": "/(.*)",
+      "dest": "/api/index.php"
+    }
+  ],
+  "build": {
+    "env": {
+      "COMPOSER_ALLOW_SUPERUSER": "1"
+    }
+  }
+}