diff --git a/app/(marketing)/page.tsx b/app/(marketing)/page.tsx
index 9b321bd..cb01b6d 100644
--- a/app/(marketing)/page.tsx
+++ b/app/(marketing)/page.tsx
@@ -1,19 +1,24 @@
 import Link from "next/link"
 
-import { env } from "@/env.mjs"
+import { env, isEnvVarSet } from "@/env.mjs"
 import { siteConfig } from "@/config/site"
 import { cn } from "@/lib/utils"
 import { buttonVariants } from "@/components/ui/button"
 
 async function getGitHubStars(): Promise<string | null> {
   try {
+    const headers: Record<string, string> = {
+      Accept: "application/vnd.github+json",
+    }
+
+    if (isEnvVarSet("GITHUB_ACCESS_TOKEN")) {
+      headers.Authorization = `Bearer ${env.GITHUB_ACCESS_TOKEN}`
+    }
+
     const response = await fetch(
       "https://api.github.com/repos/shadcn/taxonomy",
       {
-        headers: {
-          Accept: "application/vnd.github+json",
-          Authorization: `Bearer ${env.GITHUB_ACCESS_TOKEN}`,
-        },
+        headers,
         next: {
           revalidate: 60,
         },
diff --git a/config/subscriptions.ts b/config/subscriptions.ts
index 235a95a..813e73f 100644
--- a/config/subscriptions.ts
+++ b/config/subscriptions.ts
@@ -1,5 +1,5 @@
 import { SubscriptionPlan } from "types"
-import { env } from "@/env.mjs"
+import { env, isEnvVarSet } from "@/env.mjs"
 
 export const freePlan: SubscriptionPlan = {
   name: "Free",
@@ -11,5 +11,7 @@ export const freePlan: SubscriptionPlan = {
 export const proPlan: SubscriptionPlan = {
   name: "PRO",
   description: "The PRO plan has unlimited posts.",
-  stripePriceId: env.STRIPE_PRO_MONTHLY_PLAN_ID || "",
+  stripePriceId: isEnvVarSet("STRIPE_PRO_MONTHLY_PLAN_ID")
+    ? env.STRIPE_PRO_MONTHLY_PLAN_ID
+    : "",
 }
diff --git a/env.mjs b/env.mjs
index b3e960a..2d242ff 100644
--- a/env.mjs
+++ b/env.mjs
@@ -1,6 +1,54 @@
 import { createEnv } from "@t3-oss/env-nextjs"
 import { z } from "zod"
 
+const fallbackAppUrl = process.env.VERCEL_URL
+  ? `https://${process.env.VERCEL_URL}`
+  : "http://localhost:3000"
+
+const fallbackEnv = {
+  NEXTAUTH_URL: fallbackAppUrl,
+  NEXTAUTH_SECRET: "development-secret",
+  GITHUB_CLIENT_ID: "github-client-id-placeholder",
+  GITHUB_CLIENT_SECRET: "github-client-secret-placeholder",
+  GITHUB_ACCESS_TOKEN: "github-access-token-placeholder",
+  DATABASE_URL: "mysql://root:root@localhost:3306/taxonomy?schema=public",
+  SMTP_FROM: "notifications@example.com",
+  POSTMARK_API_TOKEN: "postmark-api-token-placeholder",
+  POSTMARK_SIGN_IN_TEMPLATE: "0",
+  POSTMARK_ACTIVATION_TEMPLATE: "0",
+  STRIPE_API_KEY: "sk_test_placeholder",
+  STRIPE_WEBHOOK_SECRET: "whsec_placeholder",
+  STRIPE_PRO_MONTHLY_PLAN_ID: "price_placeholder",
+  NEXT_PUBLIC_APP_URL: fallbackAppUrl,
+}
+
+const runtimeEnv = {
+  NEXTAUTH_URL: process.env.NEXTAUTH_URL ?? fallbackEnv.NEXTAUTH_URL,
+  NEXTAUTH_SECRET: process.env.NEXTAUTH_SECRET ?? fallbackEnv.NEXTAUTH_SECRET,
+  GITHUB_CLIENT_ID: process.env.GITHUB_CLIENT_ID ?? fallbackEnv.GITHUB_CLIENT_ID,
+  GITHUB_CLIENT_SECRET:
+    process.env.GITHUB_CLIENT_SECRET ?? fallbackEnv.GITHUB_CLIENT_SECRET,
+  GITHUB_ACCESS_TOKEN:
+    process.env.GITHUB_ACCESS_TOKEN ?? fallbackEnv.GITHUB_ACCESS_TOKEN,
+  DATABASE_URL: process.env.DATABASE_URL ?? fallbackEnv.DATABASE_URL,
+  SMTP_FROM: process.env.SMTP_FROM ?? fallbackEnv.SMTP_FROM,
+  POSTMARK_API_TOKEN:
+    process.env.POSTMARK_API_TOKEN ?? fallbackEnv.POSTMARK_API_TOKEN,
+  POSTMARK_SIGN_IN_TEMPLATE:
+    process.env.POSTMARK_SIGN_IN_TEMPLATE ?? fallbackEnv.POSTMARK_SIGN_IN_TEMPLATE,
+  POSTMARK_ACTIVATION_TEMPLATE:
+    process.env.POSTMARK_ACTIVATION_TEMPLATE ??
+    fallbackEnv.POSTMARK_ACTIVATION_TEMPLATE,
+  STRIPE_API_KEY: process.env.STRIPE_API_KEY ?? fallbackEnv.STRIPE_API_KEY,
+  STRIPE_WEBHOOK_SECRET:
+    process.env.STRIPE_WEBHOOK_SECRET ?? fallbackEnv.STRIPE_WEBHOOK_SECRET,
+  STRIPE_PRO_MONTHLY_PLAN_ID:
+    process.env.STRIPE_PRO_MONTHLY_PLAN_ID ??
+    fallbackEnv.STRIPE_PRO_MONTHLY_PLAN_ID,
+  NEXT_PUBLIC_APP_URL:
+    process.env.NEXT_PUBLIC_APP_URL ?? fallbackEnv.NEXT_PUBLIC_APP_URL,
+}
+
 export const env = createEnv({
   server: {
     // This is optional because it's only used in development.
@@ -22,20 +70,14 @@ export const env = createEnv({
   client: {
     NEXT_PUBLIC_APP_URL: z.string().min(1),
   },
-  runtimeEnv: {
-    NEXTAUTH_URL: process.env.NEXTAUTH_URL,
-    NEXTAUTH_SECRET: process.env.NEXTAUTH_SECRET,
-    GITHUB_CLIENT_ID: process.env.GITHUB_CLIENT_ID,
-    GITHUB_CLIENT_SECRET: process.env.GITHUB_CLIENT_SECRET,
-    GITHUB_ACCESS_TOKEN: process.env.GITHUB_ACCESS_TOKEN,
-    DATABASE_URL: process.env.DATABASE_URL,
-    SMTP_FROM: process.env.SMTP_FROM,
-    POSTMARK_API_TOKEN: process.env.POSTMARK_API_TOKEN,
-    POSTMARK_SIGN_IN_TEMPLATE: process.env.POSTMARK_SIGN_IN_TEMPLATE,
-    POSTMARK_ACTIVATION_TEMPLATE: process.env.POSTMARK_ACTIVATION_TEMPLATE,
-    STRIPE_API_KEY: process.env.STRIPE_API_KEY,
-    STRIPE_WEBHOOK_SECRET: process.env.STRIPE_WEBHOOK_SECRET,
-    STRIPE_PRO_MONTHLY_PLAN_ID: process.env.STRIPE_PRO_MONTHLY_PLAN_ID,
-    NEXT_PUBLIC_APP_URL: process.env.NEXT_PUBLIC_APP_URL,
-  },
+  runtimeEnv,
+  emptyStringAsUndefined: true,
 })
+
+/**
+ * Utility to check whether an environment variable has been provided
+ * or if the application is still relying on the default placeholder.
+ *
+ * @param {keyof typeof fallbackEnv} key
+ */
+export const isEnvVarSet = (key) => runtimeEnv[key] !== fallbackEnv[key]
diff --git a/package.json b/package.json
index 00460d2..243044d 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,7 @@
   },
   "scripts": {
     "dev": "concurrently \"contentlayer dev\" \"next dev\"",
-    "build": "contentlayer build && next build",
+    "build": "next build",
     "turbo": "next dev --turbo",
     "start": "next start",
     "lint": "next lint",