Support multiple client prefixes

.changeset/old-fishes-sing.md

@@ -0,0 +1,5 @@
+---
+"@t3-oss/env-core": minor
+---
+
+support multiple client prefixes

docs/src/app/docs/core/page.mdx

@@ -58,9 +58,10 @@ export const env = createEnv({
 
   /**
    * The prefix that client-side variables must have. This is enforced both at
-   * a type-level and at runtime.
+   * a type-level and at runtime. Can be a single string or an array of strings
+   * if you want to use multiple client prefixes.
    */
-  clientPrefix: "PUBLIC_",
+  clientPrefix: "PUBLIC_", // or ["PUBLIC_", "NEXT_PUBLIC_"],
 
   client: {
     PUBLIC_CLERK_PUBLISHABLE_KEY: z.string().min(1),

packages/core/src/index.ts

@@ -130,7 +130,7 @@ export interface StrictOptions<
 }
 
 export interface ClientOptions<
-  TPrefix extends string | undefined,
+  TPrefix extends string | string[] | undefined,
   TClient extends Record<string, StandardSchemaV1>,
 > {
   /**
@@ -144,11 +144,21 @@ export interface ClientOptions<
    * built with invalid env vars.
    */
   client: Partial<{
-    [TKey in keyof TClient]: TKey extends `${TPrefix}${string}`
-      ? TClient[TKey]
-      : ErrorMessage<`${TKey extends string
-          ? TKey
-          : never} is not prefixed with ${TPrefix}.`>;
+    [TKey in keyof TClient]: TPrefix extends string
+      ? TKey extends `${TPrefix}${string}`
+        ? TClient[TKey]
+        : ErrorMessage<`${TKey extends string
+            ? TKey
+            : never} is not prefixed with ${TPrefix}.`>
+      : TPrefix extends string[]
+        ? TKey extends `${infer Prefix}${string}`
+          ? Prefix extends TPrefix[number]
+            ? TClient[TKey]
+            : ErrorMessage<`${TKey extends string
+                ? TKey
+                : never} is not prefixed with any of ${TPrefix[number]}.`>
+          : never
+        : never;
   }>;
 }
 
@@ -278,7 +288,14 @@ export function createEnv<
 
   const isServerAccess = (prop: string) => {
     if (!opts.clientPrefix) return true;
-    return !prop.startsWith(opts.clientPrefix) && !(prop in _shared);
+
+    const prefixes = Array.isArray(opts.clientPrefix)
+      ? opts.clientPrefix
+      : [opts.clientPrefix];
+
+    return !prefixes.some(
+      (prefix) => prop.startsWith(prefix) && prop in _shared,
+    );
   };
   const isValidServerAccess = (prop: string) => {
     return isServer || !isServerAccess(prop);