Add deployment id header for rsc payload if present

packages/next/src/client/components/router-reducer/fetch-server-response.ts

@@ -80,6 +80,7 @@ export async function fetchServerResponse(
     [NEXT_ROUTER_STATE_TREE_HEADER]: string
     [NEXT_URL]?: string
     [NEXT_ROUTER_PREFETCH_HEADER]?: '1'
+    'x-deployment-id'?: string
     [NEXT_HMR_REFRESH_HEADER]?: '1'
     // A header that is only added in test mode to assert on fetch priority
     'Next-Test-Fetch-Priority'?: RequestInit['priority']
@@ -110,6 +111,10 @@ export async function fetchServerResponse(
     headers[NEXT_URL] = nextUrl
   }
 
+  if (process.env.NEXT_DEPLOYMENT_ID) {
+    headers['x-deployment-id'] = process.env.NEXT_DEPLOYMENT_ID
+  }
+
   const uniqueCacheQuery = hexHash(
     [
       headers[NEXT_ROUTER_PREFETCH_HEADER] || '0',

test/production/deployment-id-handling/app/app/from-app/page.tsx

@@ -1,6 +1,8 @@
 'use client'
-import testImage from '../../public/test.jpg'
+
+import Link from 'next/link'
 import Image from 'next/image'
+import testImage from '../../public/test.jpg'
 
 export default function Page() {
   return (
@@ -19,6 +21,9 @@ export default function Page() {
       >
         click me
       </button>
+      <Link id="other-app" href="/other-app">
+        other app
+      </Link>
     </>
   )
 }

test/production/deployment-id-handling/app/app/other-app/page.tsx

@@ -0,0 +1,24 @@
+'use client'
+import testImage from '../../public/test.jpg'
+import Image from 'next/image'
+
+export default function Page() {
+  return (
+    <>
+      <h1>other app</h1>
+      <Image src={testImage} alt="test" />
+      <p id="deploymentId">{process.env.NEXT_DEPLOYMENT_ID}</p>
+
+      <button
+        onClick={() => {
+          import('../../data').then((mod) => {
+            console.log('loaded data', mod)
+          })
+        }}
+        id="dynamic-import"
+      >
+        click me
+      </button>
+    </>
+  )
+}

test/production/deployment-id-handling/app/global.css

@@ -1,5 +1,5 @@
 html {
-  font-size: 14rem;
+  font-size: 1.4rem;
   color: white;
   background: black;
 }

test/production/deployment-id-handling/deployment-id-handling.test.ts

@@ -1,5 +1,5 @@
 import { nextTestSetup } from 'e2e-utils'
-import { check } from 'next-test-utils'
+import { check, retry } from 'next-test-utils'
 import { join } from 'node:path'
 
 describe.each(['NEXT_DEPLOYMENT_ID', 'CUSTOM_DEPLOYMENT_ID'])(
@@ -51,7 +51,9 @@ describe.each(['NEXT_DEPLOYMENT_ID', 'CUSTOM_DEPLOYMENT_ID'])(
         const requests = []
 
         browser.on('request', (req) => {
-          requests.push(req.url())
+          if (req.url().includes('/_next/static')) {
+            requests.push(req.url())
+          }
         })
 
         await browser.elementByCss('#dynamic-import').click()
@@ -81,8 +83,37 @@ describe.each(['NEXT_DEPLOYMENT_ID', 'CUSTOM_DEPLOYMENT_ID'])(
         })
       }
     )
+
+    it('should contain deployment id in RSC payload request headers', async () => {
+      const rscHeaders = []
+      const browser = await next.browser('/from-app', {
+        beforePageLoad(page) {
+          page.on('request', async (req) => {
+            const headers = await req.allHeaders()
+            if (headers['rsc']) {
+              rscHeaders.push(headers)
+            }
+          })
+        },
+      })
+
+      await browser.elementByCss('#other-app').click()
+
+      await retry(async () => {
+        expect(await browser.elementByCss('h1').text()).toBe('other app')
+        expect(await browser.url()).toContain('/other-app')
+        expect(rscHeaders.length).toBeGreaterThan(0)
+      })
+
+      expect(
+        rscHeaders.every(
+          (headers) => headers['x-deployment-id'] === deploymentId
+        )
+      ).toBe(true)
+    })
   }
 )
+
 describe('deployment-id-handling disabled', () => {
   const deploymentId = Date.now() + ''
   const { next } = nextTestSetup({

test/turbopack-build-tests-manifest.json

@@ -15712,10 +15712,12 @@
         "deployment-id-handling enabled with CUSTOM_DEPLOYMENT_ID should append dpl query to all assets correctly for /from-app",
         "deployment-id-handling enabled with CUSTOM_DEPLOYMENT_ID should append dpl query to all assets correctly for /from-app/edge",
         "deployment-id-handling enabled with CUSTOM_DEPLOYMENT_ID should append dpl query to all assets correctly for /pages-edge",
+        "deployment-id-handling enabled with CUSTOM_DEPLOYMENT_ID should contain deployment id in RSC payload request headers",
         "deployment-id-handling enabled with NEXT_DEPLOYMENT_ID should append dpl query to all assets correctly for /",
         "deployment-id-handling enabled with NEXT_DEPLOYMENT_ID should append dpl query to all assets correctly for /from-app",
         "deployment-id-handling enabled with NEXT_DEPLOYMENT_ID should append dpl query to all assets correctly for /from-app/edge",
-        "deployment-id-handling enabled with NEXT_DEPLOYMENT_ID should append dpl query to all assets correctly for /pages-edge"
+        "deployment-id-handling enabled with NEXT_DEPLOYMENT_ID should append dpl query to all assets correctly for /pages-edge",
+        "deployment-id-handling enabled with NEXT_DEPLOYMENT_ID should contain deployment id in RSC payload request headers"
       ],
       "pending": [],
       "flakey": [],