fix: prevent dev/staging subdomains from being indexed by search engines

app/robots.ts

@@ -1,18 +1,9 @@
 import type { MetadataRoute } from "next"
 
-import { SITE_URL } from "@/lib/constants"
+import { IS_PRODUCTION_DEPLOY, SITE_URL } from "@/lib/constants"
 
 export default function robots(): MetadataRoute.Robots {
-  let hostname = ""
-  try {
-    hostname = new URL(SITE_URL).hostname
-  } catch (error) {
-    console.error("Error getting hostname", error)
-  }
-
-  const isProduction = hostname === "ethereum.org"
-
-  if (!isProduction) {
+  if (!IS_PRODUCTION_DEPLOY) {
     return {
       rules: [{ userAgent: "*", disallow: "/" }],
       sitemap: [],

netlify.toml

@@ -40,3 +40,11 @@
 
 [functions]
   included_files = ["i18n.config.json", "src/intl/**/*", "src/data-layer/mocks/**/*"]
+
+# Override SITE_URL for named branches with custom subdomains so canonical
+# URLs and OG metadata use the custom domain instead of *.netlify.app.
+[context.dev.environment]
+  NEXT_PUBLIC_SITE_URL = "https://dev.ethereum.org"
+
+[context.staging.environment]
+  NEXT_PUBLIC_SITE_URL = "https://staging.ethereum.org"

next.config.js

@@ -35,9 +35,18 @@ module.exports = (phase, { defaultConfig }) => {
     ...defaultConfig,
     reactStrictMode: true,
     env: {
-      // Context is used to determine the environment for Sentry
+      // Netlify build-time vars inlined so they're available at SSR runtime.
       // ref. https://docs.netlify.com/configure-builds/environment-variables/#build-metadata
       NEXT_PUBLIC_CONTEXT: process.env.CONTEXT,
+      // Resolve site URL once at build time. NEXT_PUBLIC_SITE_URL (set in
+      // netlify.toml for dev/staging) takes precedence, then Netlify's
+      // deploy-specific URLs, falling back to the production domain.
+      NEXT_PUBLIC_SITE_URL:
+        process.env.NEXT_PUBLIC_SITE_URL ||
+        process.env.DEPLOY_PRIME_URL ||
+        process.env.DEPLOY_URL ||
+        process.env.URL ||
+        "https://ethereum.org",
     },
     webpack: (config) => {
       config.module.rules.push({

src/lib/constants.ts

@@ -24,13 +24,12 @@ export const LOCALES_CODES = BUILD_LOCALES
   ? BUILD_LOCALES.split(",")
   : i18nConfig.map(({ code }) => code)
 
-// Site urls - auto-detect from Netlify deploy context
+// Site URL - resolved at build time in next.config.js from Netlify deploy context
 export const SITE_URL =
-  process.env.NEXT_PUBLIC_SITE_URL ||
-  process.env.DEPLOY_PRIME_URL || // Branch/PR deploys
-  process.env.DEPLOY_URL || // Unique deploy URL
-  process.env.URL || // Primary site URL
-  "https://ethereum.org"
+  process.env.NEXT_PUBLIC_SITE_URL || "https://ethereum.org"
+
+export const IS_PRODUCTION_DEPLOY =
+  process.env.NEXT_PUBLIC_CONTEXT === "production"
 export const DISCORD_PATH = "https://discord.gg/ethereum-org/"
 export const ENTERPRISE_ETHEREUM_URL = "https://institutions.ethereum.org/"
 export const GITHUB_REPO_URL =

src/lib/utils/metadata.ts

@@ -1,14 +1,19 @@
 import type { Metadata } from "next"
 import { getTranslations } from "next-intl/server"
 
-import { DEFAULT_OG_IMAGE, SITE_URL } from "@/lib/constants"
+import {
+  DEFAULT_OG_IMAGE,
+  IS_PRODUCTION_DEPLOY,
+  SITE_URL,
+} from "@/lib/constants"
 
 import { getTranslatedLocales } from "../i18n/translationRegistry"
 
 import { isLocaleValidISO639_1 } from "./translations"
 import { getFullUrl } from "./url"
 
 import { routing } from "@/i18n/routing"
+
 /**
  * List of default og images for different sections
  */
@@ -136,7 +141,7 @@ export const getMetadata = async ({
     },
   }
 
-  if (SITE_URL !== "https://ethereum.org") {
+  if (!IS_PRODUCTION_DEPLOY) {
     return { ...base, robots: { index: false, follow: false } }
   }