Add config for only generating static env

packages/next/src/build/index.ts

@@ -2509,6 +2509,17 @@ export default async function build(
               buildId,
             })
           })
+
+        // users might only want to inline env during experimental generate
+        // instead of also prerendering e.g. for testmode so exit after
+        if (config.experimental.generateOnlyEnv) {
+          Log.info(
+            'Only inlining static env due to experimental.generateOnlyEnv'
+          )
+        }
+        await flushAllTraces()
+        teardownTraceSubscriber()
+        process.exit(0)
       }
 
       const middlewareManifest: MiddlewareManifest = await readManifest(

packages/next/src/server/config-schema.ts

@@ -261,6 +261,7 @@ export const configSchema: zod.ZodType<NextConfig> = z.lazy(() =>
     excludeDefaultMomentLocales: z.boolean().optional(),
     experimental: z
       .strictObject({
+        generateOnlyEnv: z.boolean().optional(),
         allowedDevOrigins: z.array(z.string()).optional(),
         nodeMiddleware: z.boolean().optional(),
         after: z.boolean().optional(),

packages/next/src/server/config-shared.ts

@@ -257,6 +257,7 @@ export interface LoggingConfig {
 }
 
 export interface ExperimentalConfig {
+  generateOnlyEnv?: boolean
   allowedDevOrigins?: string[]
   nodeMiddleware?: boolean
   cacheHandlers?: {
@@ -1135,6 +1136,7 @@ export const defaultConfig: NextConfig = {
   modularizeImports: undefined,
   outputFileTracingRoot: process.env.NEXT_PRIVATE_OUTPUT_TRACE_ROOT || '',
   experimental: {
+    generateOnlyEnv: false,
     allowedDevOrigins: [],
     nodeMiddleware: false,
     cacheLife: {