diff --git a/packages/core/src/page.ts b/packages/core/src/page.ts
index de599bd2f..7f49457f4 100644
--- a/packages/core/src/page.ts
+++ b/packages/core/src/page.ts
@@ -1,6 +1,7 @@
 import { eventHandler } from './eventHandler'
 import { fireNavigateEvent } from './events'
 import { history } from './history'
+import { prefetchedRequests } from './prefetched'
 import { Scroll } from './scroll'
 import { Component, Page, PageEvent, PageHandler, PageResolver, RouterInitParams, Visit } from './types'
 import { hrefToUrl, isSameUrlWithoutHash } from './url'
@@ -86,6 +87,10 @@ class CurrentPage {
         this.page = page
         this.cleared = false
 
+        if (this.hasOnceProps()) {
+          prefetchedRequests.updateCachedOncePropsFromCurrentPage()
+        }
+
         if (isNewComponent) {
           this.fireEventsFor('newComponent')
         }
@@ -157,6 +162,10 @@ class CurrentPage {
     return this.page
   }
 
+  public hasOnceProps(): boolean {
+    return Object.keys(this.page.onceProps ?? {}).length > 0
+  }
+
   public merge(data: Partial<Page>): void {
     this.page = { ...this.page, ...data }
   }
@@ -216,6 +225,21 @@ class CurrentPage {
   public fireEventsFor(event: PageEvent): void {
     this.listeners.filter((listener) => listener.event === event).forEach((listener) => listener.callback())
   }
+
+  public mergeOncePropsIntoResponse(response: Page, { force = false }: { force?: boolean } = {}): void {
+    Object.entries(response.onceProps ?? {}).forEach(([key, onceProp]) => {
+      const existingOnceProp = this.page.onceProps?.[key]
+
+      if (existingOnceProp === undefined) {
+        return
+      }
+
+      if (force || response.props[onceProp.prop] === undefined) {
+        response.props[onceProp.prop] = this.page.props[existingOnceProp.prop]
+        response.onceProps![key].expiresAt = existingOnceProp.expiresAt
+      }
+    })
+  }
 }
 
 export const page = new CurrentPage()
diff --git a/packages/core/src/prefetched.ts b/packages/core/src/prefetched.ts
index d37c83780..f99e18d85 100644
--- a/packages/core/src/prefetched.ts
+++ b/packages/core/src/prefetched.ts
@@ -1,5 +1,6 @@
 import { cloneDeep } from 'lodash-es'
 import { objectsAreEqual } from './objectUtils'
+import { page as currentPage } from './page'
 import { Response } from './response'
 import { timeToMs } from './time'
 import {
@@ -7,6 +8,7 @@ import {
   CacheForOption,
   InFlightPrefetch,
   InternalActiveVisit,
+  Page,
   PrefetchedResponse,
   PrefetchOptions,
   PrefetchRemovalTimer,
@@ -35,7 +37,7 @@ class PrefetchedRequests {
       return Promise.resolve()
     }
 
-    const [stale, expires] = this.extractStaleValues(cacheFor)
+    const [stale, prefetchExpiresIn] = this.extractStaleValues(cacheFor)
 
     const promise = new Promise<Response>((resolve, reject) => {
       sendFunc({
@@ -67,17 +69,26 @@ class PrefetchedRequests {
     }).then((response) => {
       this.remove(params)
 
+      const pageResponse = response.getPageResponse()
+
+      currentPage.mergeOncePropsIntoResponse(pageResponse)
+
       this.cached.push({
         params: { ...params },
         staleTimestamp: Date.now() + stale,
+        expiresAt: Date.now() + prefetchExpiresIn,
         response: promise,
-        singleUse: expires === 0,
+        singleUse: prefetchExpiresIn === 0,
         timestamp: Date.now(),
         inFlight: false,
         tags: Array.isArray(cacheTags) ? cacheTags : [cacheTags],
       })
 
-      this.scheduleForRemoval(params, expires)
+      const oncePropExpiresIn = this.getShortestOncePropTtl(pageResponse)
+      this.scheduleForRemoval(
+        params,
+        oncePropExpiresIn ? Math.min(prefetchExpiresIn, oncePropExpiresIn) : prefetchExpiresIn,
+      )
       this.removeFromInFlight(params)
 
       response.handlePrefetch()
@@ -258,6 +269,43 @@ class PrefetchedRequests {
       ],
     )
   }
+
+  public updateCachedOncePropsFromCurrentPage(): void {
+    this.cached.forEach((prefetched) => {
+      prefetched.response.then((response) => {
+        const pageResponse = response.getPageResponse()
+
+        currentPage.mergeOncePropsIntoResponse(pageResponse, { force: true })
+
+        const oncePropExpiresIn = this.getShortestOncePropTtl(pageResponse)
+
+        if (oncePropExpiresIn === null) {
+          return
+        }
+
+        const prefetchExpiresIn = prefetched.expiresAt - Date.now()
+        const expiresIn = Math.min(prefetchExpiresIn, oncePropExpiresIn)
+
+        if (expiresIn > 0) {
+          this.scheduleForRemoval(prefetched.params, expiresIn)
+        } else {
+          this.remove(prefetched.params)
+        }
+      })
+    })
+  }
+
+  protected getShortestOncePropTtl(page: Page): number | null {
+    const expiryTimestamps = Object.values(page.onceProps ?? {})
+      .map((onceProp) => onceProp.expiresAt)
+      .filter((expiresAt): expiresAt is number => !!expiresAt)
+
+    if (expiryTimestamps.length === 0) {
+      return null
+    }
+
+    return Math.min(...expiryTimestamps) - Date.now()
+  }
 }
 
 export const prefetchedRequests = new PrefetchedRequests()
diff --git a/packages/core/src/request.ts b/packages/core/src/request.ts
index f062c7976..b8b65fd56 100644
--- a/packages/core/src/request.ts
+++ b/packages/core/src/request.ts
@@ -138,8 +138,18 @@ export class Request {
       'X-Inertia': true,
     }
 
-    if (currentPage.get().version) {
-      headers['X-Inertia-Version'] = currentPage.get().version
+    const page = currentPage.get()
+
+    if (page.version) {
+      headers['X-Inertia-Version'] = page.version
+    }
+
+    const onceProps = Object.entries(page.onceProps || {})
+      .filter(([, onceProp]) => !onceProp.expiresAt || onceProp.expiresAt > Date.now())
+      .map(([key]) => key)
+
+    if (onceProps.length > 0) {
+      headers['X-Inertia-Except-Once-Props'] = onceProps.join(',')
     }
 
     return headers
diff --git a/packages/core/src/response.ts b/packages/core/src/response.ts
index 3562f953e..345f72b5c 100644
--- a/packages/core/src/response.ts
+++ b/packages/core/src/response.ts
@@ -95,6 +95,10 @@ export class Response {
     this.requestParams.merge(params)
   }
 
+  public getPageResponse(): Page {
+    return (this.response.data = this.getDataFromResponse(this.response.data))
+  }
+
   protected async handleNonInertiaResponse() {
     if (this.isLocationVisit()) {
       const locationUrl = hrefToUrl(this.getHeader('x-inertia-location'))
@@ -158,13 +162,14 @@ export class Response {
   }
 
   protected async setPage(): Promise<void> {
-    const pageResponse = this.getDataFromResponse(this.response.data)
+    const pageResponse = this.getPageResponse()
 
     if (!this.shouldSetPage(pageResponse)) {
       return Promise.resolve()
     }
 
     this.mergeProps(pageResponse)
+    currentPage.mergeOncePropsIntoResponse(pageResponse)
     this.preserveEqualProps(pageResponse)
 
     await this.setRememberedState(pageResponse)
diff --git a/packages/core/src/types.ts b/packages/core/src/types.ts
index 1ef98ca45..67f89c817 100644
--- a/packages/core/src/types.ts
+++ b/packages/core/src/types.ts
@@ -173,6 +173,13 @@ export interface Page<SharedProps extends PageProps = PageProps> {
   deepMergeProps?: string[]
   matchPropsOn?: string[]
   scrollProps?: Record<keyof PageProps, ScrollProp>
+  onceProps?: Record<
+    string,
+    {
+      prop: keyof PageProps
+      expiresAt?: number | null
+    }
+  >
 
   /** @internal */
   rememberedState: Record<string, unknown>
@@ -564,6 +571,7 @@ export type PrefetchCancellationToken = {
 export type PrefetchedResponse = PrefetchObject & {
   staleTimestamp: number
   timestamp: number
+  expiresAt: number
   singleUse: boolean
   inFlight: false
   tags: string[]
diff --git a/packages/react/test-app/Pages/OnceProps/CustomKeyPageA.tsx b/packages/react/test-app/Pages/OnceProps/CustomKeyPageA.tsx
new file mode 100644
index 000000000..16e033dd1
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/CustomKeyPageA.tsx
@@ -0,0 +1,11 @@
+import { Link } from '@inertiajs/react'
+
+export default ({ userPermissions, bar }: { userPermissions: string; bar: string }) => {
+  return (
+    <>
+      <p id="permissions">Permissions: {userPermissions}</p>
+      <p id="bar">Bar: {bar}</p>
+      <Link href="/once-props/custom-key/b">Go to Custom Key Page B</Link>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/CustomKeyPageB.tsx b/packages/react/test-app/Pages/OnceProps/CustomKeyPageB.tsx
new file mode 100644
index 000000000..92c94c205
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/CustomKeyPageB.tsx
@@ -0,0 +1,11 @@
+import { Link } from '@inertiajs/react'
+
+export default ({ permissions, bar }: { permissions: string; bar: string }) => {
+  return (
+    <>
+      <p id="permissions">Permissions: {permissions}</p>
+      <p id="bar">Bar: {bar}</p>
+      <Link href="/once-props/custom-key/a">Go to Custom Key Page A</Link>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/DeferredPageA.tsx b/packages/react/test-app/Pages/OnceProps/DeferredPageA.tsx
new file mode 100644
index 000000000..727b225f1
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/DeferredPageA.tsx
@@ -0,0 +1,26 @@
+import { Deferred, Link, usePage } from '@inertiajs/react'
+
+const Foo = () => {
+  const { foo } = usePage<{ foo?: { text: string } }>().props
+
+  return <>{foo?.text}</>
+}
+
+export default ({ bar }: { bar: string }) => {
+  return (
+    <>
+      <Deferred data="foo" fallback={<div>Loading foo...</div>}>
+        <p id="foo">
+          Foo: <Foo />
+        </p>
+      </Deferred>
+
+      <p id="bar">Bar: {bar}</p>
+
+      <Link href="/once-props/deferred/b">Go to Deferred Page B</Link>
+      <Link href="/once-props/deferred/c" prefetch="mount">
+        Go to Deferred Page C
+      </Link>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/DeferredPageB.tsx b/packages/react/test-app/Pages/OnceProps/DeferredPageB.tsx
new file mode 100644
index 000000000..d941c6fd9
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/DeferredPageB.tsx
@@ -0,0 +1,23 @@
+import { Deferred, Link, usePage } from '@inertiajs/react'
+
+const Foo = () => {
+  const { foo } = usePage<{ foo?: { text: string } }>().props
+
+  return <>{foo?.text}</>
+}
+
+export default ({ bar }: { bar: string }) => {
+  return (
+    <>
+      <Deferred data="foo" fallback={<div>Loading foo...</div>}>
+        <p id="foo">
+          Foo: <Foo />
+        </p>
+      </Deferred>
+
+      <p id="bar">Bar: {bar}</p>
+
+      <Link href="/once-props/deferred/a">Go to Deferred Page A</Link>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/DeferredPageC.tsx b/packages/react/test-app/Pages/OnceProps/DeferredPageC.tsx
new file mode 100644
index 000000000..d941c6fd9
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/DeferredPageC.tsx
@@ -0,0 +1,23 @@
+import { Deferred, Link, usePage } from '@inertiajs/react'
+
+const Foo = () => {
+  const { foo } = usePage<{ foo?: { text: string } }>().props
+
+  return <>{foo?.text}</>
+}
+
+export default ({ bar }: { bar: string }) => {
+  return (
+    <>
+      <Deferred data="foo" fallback={<div>Loading foo...</div>}>
+        <p id="foo">
+          Foo: <Foo />
+        </p>
+      </Deferred>
+
+      <p id="bar">Bar: {bar}</p>
+
+      <Link href="/once-props/deferred/a">Go to Deferred Page A</Link>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/MergePageA.tsx b/packages/react/test-app/Pages/OnceProps/MergePageA.tsx
new file mode 100644
index 000000000..1d0b5f38d
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/MergePageA.tsx
@@ -0,0 +1,12 @@
+import { Link, router } from '@inertiajs/react'
+
+export default ({ items, bar }: { items: string[]; bar: string }) => {
+  return (
+    <>
+      <p id="items">Items count: {items.length}</p>
+      <p id="bar">Bar: {bar}</p>
+      <Link href="/once-props/merge/b">Go to Merge Page B</Link>
+      <button onClick={() => router.reload({ only: ['items'] })}>Load more items</button>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/MergePageB.tsx b/packages/react/test-app/Pages/OnceProps/MergePageB.tsx
new file mode 100644
index 000000000..5895ab062
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/MergePageB.tsx
@@ -0,0 +1,12 @@
+import { Link, router } from '@inertiajs/react'
+
+export default ({ items, bar }: { items: string[]; bar: string }) => {
+  return (
+    <>
+      <p id="items">Items count: {items.length}</p>
+      <p id="bar">Bar: {bar}</p>
+      <Link href="/once-props/merge/a">Go to Merge Page A</Link>
+      <button onClick={() => router.reload({ only: ['items'] })}>Load more items</button>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/OptionalPageA.tsx b/packages/react/test-app/Pages/OnceProps/OptionalPageA.tsx
new file mode 100644
index 000000000..acfd2fb40
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/OptionalPageA.tsx
@@ -0,0 +1,12 @@
+import { Link, router } from '@inertiajs/react'
+
+export default ({ foo, bar }: { foo?: string; bar: string }) => {
+  return (
+    <>
+      <p id="foo">Foo: {foo ?? 'not loaded'}</p>
+      <p id="bar">Bar: {bar}</p>
+      <Link href="/once-props/optional/b">Go to Optional Page B</Link>
+      <button onClick={() => router.reload({ only: ['foo'] })}>Load foo</button>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/OptionalPageB.tsx b/packages/react/test-app/Pages/OnceProps/OptionalPageB.tsx
new file mode 100644
index 000000000..fd7e24f4d
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/OptionalPageB.tsx
@@ -0,0 +1,12 @@
+import { Link, router } from '@inertiajs/react'
+
+export default ({ foo, bar }: { foo?: string; bar: string }) => {
+  return (
+    <>
+      <p id="foo">Foo: {foo ?? 'not loaded'}</p>
+      <p id="bar">Bar: {bar}</p>
+      <Link href="/once-props/optional/a">Go to Optional Page A</Link>
+      <button onClick={() => router.reload({ only: ['foo'] })}>Load foo</button>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/PageA.tsx b/packages/react/test-app/Pages/OnceProps/PageA.tsx
new file mode 100644
index 000000000..a903331a9
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/PageA.tsx
@@ -0,0 +1,20 @@
+import { Link, router } from '@inertiajs/react'
+
+export default ({ foo, bar }: { foo: string; bar: string }) => {
+  return (
+    <>
+      <p id="foo">Foo: {foo}</p>
+      <p id="bar">Bar: {bar}</p>
+      <Link href="/once-props/page-b">Go to Page B</Link>
+      <Link href="/once-props/page-c">Go to Page C</Link>
+      <Link href="/once-props/page-d" prefetch="mount">
+        Go to Page D
+      </Link>
+      <Link href="/once-props/page-e" prefetch="mount" cacheFor={1000}>
+        Go to Page E (short cache)
+      </Link>
+      <button onClick={() => router.reload({ only: ['foo'] })}>Reload (only foo)</button>
+      <button onClick={() => router.replaceProp('foo', 'replaced-foo')}>Replace foo</button>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/PageB.tsx b/packages/react/test-app/Pages/OnceProps/PageB.tsx
new file mode 100644
index 000000000..eff0963c8
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/PageB.tsx
@@ -0,0 +1,12 @@
+import { Link, router } from '@inertiajs/react'
+
+export default ({ foo, bar }: { foo: string; bar: string }) => {
+  return (
+    <>
+      <p id="foo">Foo: {foo}</p>
+      <p id="bar">Bar: {bar}</p>
+      <Link href="/once-props/page-a">Go to Page A</Link>
+      <button onClick={() => router.reload({ only: ['foo'] })}>Reload (only foo)</button>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/PageC.tsx b/packages/react/test-app/Pages/OnceProps/PageC.tsx
new file mode 100644
index 000000000..a02e99272
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/PageC.tsx
@@ -0,0 +1,13 @@
+import { Link } from '@inertiajs/react'
+
+export default () => {
+  return (
+    <>
+      <Link href="/once-props/page-a">Go to Page A</Link>
+      <Link href="/once-props/page-b">Go to Page B</Link>
+      <Link href="/once-props/page-d" prefetch="mount">
+        Go to Page D
+      </Link>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/PageD.tsx b/packages/react/test-app/Pages/OnceProps/PageD.tsx
new file mode 100644
index 000000000..0e20e29d9
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/PageD.tsx
@@ -0,0 +1,8 @@
+export default ({ foo, bar }: { foo: string; bar: string }) => {
+  return (
+    <>
+      <p id="foo">Foo: {foo}</p>
+      <p id="bar">Bar: {bar}</p>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/PageE.tsx b/packages/react/test-app/Pages/OnceProps/PageE.tsx
new file mode 100644
index 000000000..0e20e29d9
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/PageE.tsx
@@ -0,0 +1,8 @@
+export default ({ foo, bar }: { foo: string; bar: string }) => {
+  return (
+    <>
+      <p id="foo">Foo: {foo}</p>
+      <p id="bar">Bar: {bar}</p>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/TtlPageA.tsx b/packages/react/test-app/Pages/OnceProps/TtlPageA.tsx
new file mode 100644
index 000000000..11e1a4e53
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/TtlPageA.tsx
@@ -0,0 +1,15 @@
+import { Link, router } from '@inertiajs/react'
+
+export default ({ foo, bar }: { foo: string; bar: string }) => {
+  return (
+    <>
+      <p id="foo">Foo: {foo}</p>
+      <p id="bar">Bar: {bar}</p>
+      <Link href="/once-props/ttl/b">Go to TTL Page B</Link>
+      <Link href="/once-props/ttl/c" prefetch="mount">
+        Go to TTL Page C
+      </Link>
+      <button onClick={() => router.reload({ only: ['foo'] })}>Reload foo</button>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/TtlPageB.tsx b/packages/react/test-app/Pages/OnceProps/TtlPageB.tsx
new file mode 100644
index 000000000..070258ada
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/TtlPageB.tsx
@@ -0,0 +1,11 @@
+import { Link } from '@inertiajs/react'
+
+export default ({ foo, bar }: { foo: string; bar: string }) => {
+  return (
+    <>
+      <p id="foo">Foo: {foo}</p>
+      <p id="bar">Bar: {bar}</p>
+      <Link href="/once-props/ttl/a">Go to TTL Page A</Link>
+    </>
+  )
+}
diff --git a/packages/react/test-app/Pages/OnceProps/TtlPageC.tsx b/packages/react/test-app/Pages/OnceProps/TtlPageC.tsx
new file mode 100644
index 000000000..070258ada
--- /dev/null
+++ b/packages/react/test-app/Pages/OnceProps/TtlPageC.tsx
@@ -0,0 +1,11 @@
+import { Link } from '@inertiajs/react'
+
+export default ({ foo, bar }: { foo: string; bar: string }) => {
+  return (
+    <>
+      <p id="foo">Foo: {foo}</p>
+      <p id="bar">Bar: {bar}</p>
+      <Link href="/once-props/ttl/a">Go to TTL Page A</Link>
+    </>
+  )
+}
diff --git a/packages/svelte/test-app/Pages/OnceProps/CustomKeyPageA.svelte b/packages/svelte/test-app/Pages/OnceProps/CustomKeyPageA.svelte
new file mode 100644
index 000000000..045596c62
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/CustomKeyPageA.svelte
@@ -0,0 +1,10 @@
+<script lang="ts">
+  import { Link } from '@inertiajs/svelte'
+
+  export let userPermissions: string
+  export let bar: string
+</script>
+
+<p id="permissions">Permissions: {userPermissions}</p>
+<p id="bar">Bar: {bar}</p>
+<Link href="/once-props/custom-key/b">Go to Custom Key Page B</Link>
diff --git a/packages/svelte/test-app/Pages/OnceProps/CustomKeyPageB.svelte b/packages/svelte/test-app/Pages/OnceProps/CustomKeyPageB.svelte
new file mode 100644
index 000000000..eed728b7b
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/CustomKeyPageB.svelte
@@ -0,0 +1,10 @@
+<script lang="ts">
+  import { Link } from '@inertiajs/svelte'
+
+  export let permissions: string
+  export let bar: string
+</script>
+
+<p id="permissions">Permissions: {permissions}</p>
+<p id="bar">Bar: {bar}</p>
+<Link href="/once-props/custom-key/a">Go to Custom Key Page A</Link>
diff --git a/packages/svelte/test-app/Pages/OnceProps/DeferredPageA.svelte b/packages/svelte/test-app/Pages/OnceProps/DeferredPageA.svelte
new file mode 100644
index 000000000..2d8bccc17
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/DeferredPageA.svelte
@@ -0,0 +1,19 @@
+<script lang="ts">
+  import { Deferred, Link } from '@inertiajs/svelte'
+
+  export let foo: { text: string } | undefined
+  export let bar: string
+</script>
+
+<Deferred data="foo">
+  <svelte:fragment slot="fallback">
+    <div>Loading foo...</div>
+  </svelte:fragment>
+
+  <p id="foo">Foo: {foo?.text}</p>
+</Deferred>
+
+<p id="bar">Bar: {bar}</p>
+
+<Link href="/once-props/deferred/b">Go to Deferred Page B</Link>
+<Link href="/once-props/deferred/c" prefetch="mount">Go to Deferred Page C</Link>
diff --git a/packages/svelte/test-app/Pages/OnceProps/DeferredPageB.svelte b/packages/svelte/test-app/Pages/OnceProps/DeferredPageB.svelte
new file mode 100644
index 000000000..93c76c720
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/DeferredPageB.svelte
@@ -0,0 +1,18 @@
+<script lang="ts">
+  import { Deferred, Link } from '@inertiajs/svelte'
+
+  export let foo: { text: string } | undefined
+  export let bar: string
+</script>
+
+<Deferred data="foo">
+  <svelte:fragment slot="fallback">
+    <div>Loading foo...</div>
+  </svelte:fragment>
+
+  <p id="foo">Foo: {foo?.text}</p>
+</Deferred>
+
+<p id="bar">Bar: {bar}</p>
+
+<Link href="/once-props/deferred/a">Go to Deferred Page A</Link>
diff --git a/packages/svelte/test-app/Pages/OnceProps/DeferredPageC.svelte b/packages/svelte/test-app/Pages/OnceProps/DeferredPageC.svelte
new file mode 100644
index 000000000..93c76c720
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/DeferredPageC.svelte
@@ -0,0 +1,18 @@
+<script lang="ts">
+  import { Deferred, Link } from '@inertiajs/svelte'
+
+  export let foo: { text: string } | undefined
+  export let bar: string
+</script>
+
+<Deferred data="foo">
+  <svelte:fragment slot="fallback">
+    <div>Loading foo...</div>
+  </svelte:fragment>
+
+  <p id="foo">Foo: {foo?.text}</p>
+</Deferred>
+
+<p id="bar">Bar: {bar}</p>
+
+<Link href="/once-props/deferred/a">Go to Deferred Page A</Link>
diff --git a/packages/svelte/test-app/Pages/OnceProps/MergePageA.svelte b/packages/svelte/test-app/Pages/OnceProps/MergePageA.svelte
new file mode 100644
index 000000000..c2141f9c9
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/MergePageA.svelte
@@ -0,0 +1,11 @@
+<script lang="ts">
+  import { Link, router } from '@inertiajs/svelte'
+
+  export let items: string[]
+  export let bar: string
+</script>
+
+<p id="items">Items count: {items.length}</p>
+<p id="bar">Bar: {bar}</p>
+<Link href="/once-props/merge/b">Go to Merge Page B</Link>
+<button on:click={() => router.reload({ only: ['items'] })}>Load more items</button>
diff --git a/packages/svelte/test-app/Pages/OnceProps/MergePageB.svelte b/packages/svelte/test-app/Pages/OnceProps/MergePageB.svelte
new file mode 100644
index 000000000..d0d9f62ce
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/MergePageB.svelte
@@ -0,0 +1,11 @@
+<script lang="ts">
+  import { Link, router } from '@inertiajs/svelte'
+
+  export let items: string[]
+  export let bar: string
+</script>
+
+<p id="items">Items count: {items.length}</p>
+<p id="bar">Bar: {bar}</p>
+<Link href="/once-props/merge/a">Go to Merge Page A</Link>
+<button on:click={() => router.reload({ only: ['items'] })}>Load more items</button>
diff --git a/packages/svelte/test-app/Pages/OnceProps/OptionalPageA.svelte b/packages/svelte/test-app/Pages/OnceProps/OptionalPageA.svelte
new file mode 100644
index 000000000..cb41e7b73
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/OptionalPageA.svelte
@@ -0,0 +1,11 @@
+<script lang="ts">
+  import { Link, router } from '@inertiajs/svelte'
+
+  export let foo: string | undefined
+  export let bar: string
+</script>
+
+<p id="foo">Foo: {foo ?? 'not loaded'}</p>
+<p id="bar">Bar: {bar}</p>
+<Link href="/once-props/optional/b">Go to Optional Page B</Link>
+<button on:click={() => router.reload({ only: ['foo'] })}>Load foo</button>
diff --git a/packages/svelte/test-app/Pages/OnceProps/OptionalPageB.svelte b/packages/svelte/test-app/Pages/OnceProps/OptionalPageB.svelte
new file mode 100644
index 000000000..4e4ea88ef
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/OptionalPageB.svelte
@@ -0,0 +1,11 @@
+<script lang="ts">
+  import { Link, router } from '@inertiajs/svelte'
+
+  export let foo: string | undefined
+  export let bar: string
+</script>
+
+<p id="foo">Foo: {foo ?? 'not loaded'}</p>
+<p id="bar">Bar: {bar}</p>
+<Link href="/once-props/optional/a">Go to Optional Page A</Link>
+<button on:click={() => router.reload({ only: ['foo'] })}>Load foo</button>
diff --git a/packages/svelte/test-app/Pages/OnceProps/PageA.svelte b/packages/svelte/test-app/Pages/OnceProps/PageA.svelte
new file mode 100644
index 000000000..5c8aeb987
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/PageA.svelte
@@ -0,0 +1,15 @@
+<script lang="ts">
+  import { Link, router } from '@inertiajs/svelte'
+
+  export let foo: string
+  export let bar: string
+</script>
+
+<p id="foo">Foo: {foo}</p>
+<p id="bar">Bar: {bar}</p>
+<Link href="/once-props/page-b">Go to Page B</Link>
+<Link href="/once-props/page-c">Go to Page C</Link>
+<Link href="/once-props/page-d" prefetch="mount">Go to Page D</Link>
+<Link href="/once-props/page-e" prefetch="mount" cacheFor={1000}>Go to Page E (short cache)</Link>
+<button on:click={() => router.reload({ only: ['foo'] })}>Reload (only foo)</button>
+<button on:click={() => router.replaceProp('foo', 'replaced-foo')}>Replace foo</button>
diff --git a/packages/svelte/test-app/Pages/OnceProps/PageB.svelte b/packages/svelte/test-app/Pages/OnceProps/PageB.svelte
new file mode 100644
index 000000000..7aa1eba84
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/PageB.svelte
@@ -0,0 +1,11 @@
+<script lang="ts">
+  import { Link, router } from '@inertiajs/svelte'
+
+  export let foo: string
+  export let bar: string
+</script>
+
+<p id="foo">Foo: {foo}</p>
+<p id="bar">Bar: {bar}</p>
+<Link href="/once-props/page-a">Go to Page A</Link>
+<button on:click={() => router.reload({ only: ['foo'] })}>Reload (only foo)</button>
diff --git a/packages/svelte/test-app/Pages/OnceProps/PageC.svelte b/packages/svelte/test-app/Pages/OnceProps/PageC.svelte
new file mode 100644
index 000000000..b9b6e394f
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/PageC.svelte
@@ -0,0 +1,7 @@
+<script lang="ts">
+  import { Link } from '@inertiajs/svelte'
+</script>
+
+<Link href="/once-props/page-a">Go to Page A</Link>
+<Link href="/once-props/page-b">Go to Page B</Link>
+<Link href="/once-props/page-d" prefetch="mount">Go to Page D</Link>
diff --git a/packages/svelte/test-app/Pages/OnceProps/PageD.svelte b/packages/svelte/test-app/Pages/OnceProps/PageD.svelte
new file mode 100644
index 000000000..4811336b4
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/PageD.svelte
@@ -0,0 +1,7 @@
+<script lang="ts">
+  export let foo: string
+  export let bar: string
+</script>
+
+<p id="foo">Foo: {foo}</p>
+<p id="bar">Bar: {bar}</p>
diff --git a/packages/svelte/test-app/Pages/OnceProps/PageE.svelte b/packages/svelte/test-app/Pages/OnceProps/PageE.svelte
new file mode 100644
index 000000000..4811336b4
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/PageE.svelte
@@ -0,0 +1,7 @@
+<script lang="ts">
+  export let foo: string
+  export let bar: string
+</script>
+
+<p id="foo">Foo: {foo}</p>
+<p id="bar">Bar: {bar}</p>
diff --git a/packages/svelte/test-app/Pages/OnceProps/TtlPageA.svelte b/packages/svelte/test-app/Pages/OnceProps/TtlPageA.svelte
new file mode 100644
index 000000000..e23f2a1f9
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/TtlPageA.svelte
@@ -0,0 +1,12 @@
+<script lang="ts">
+  import { Link, router } from '@inertiajs/svelte'
+
+  export let foo: string
+  export let bar: string
+</script>
+
+<p id="foo">Foo: {foo}</p>
+<p id="bar">Bar: {bar}</p>
+<Link href="/once-props/ttl/b">Go to TTL Page B</Link>
+<Link href="/once-props/ttl/c" prefetch="mount">Go to TTL Page C</Link>
+<button on:click={() => router.reload({ only: ['foo'] })}>Reload foo</button>
diff --git a/packages/svelte/test-app/Pages/OnceProps/TtlPageB.svelte b/packages/svelte/test-app/Pages/OnceProps/TtlPageB.svelte
new file mode 100644
index 000000000..6774ce6b8
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/TtlPageB.svelte
@@ -0,0 +1,10 @@
+<script lang="ts">
+  import { Link } from '@inertiajs/svelte'
+
+  export let foo: string
+  export let bar: string
+</script>
+
+<p id="foo">Foo: {foo}</p>
+<p id="bar">Bar: {bar}</p>
+<Link href="/once-props/ttl/a">Go to TTL Page A</Link>
diff --git a/packages/svelte/test-app/Pages/OnceProps/TtlPageC.svelte b/packages/svelte/test-app/Pages/OnceProps/TtlPageC.svelte
new file mode 100644
index 000000000..6774ce6b8
--- /dev/null
+++ b/packages/svelte/test-app/Pages/OnceProps/TtlPageC.svelte
@@ -0,0 +1,10 @@
+<script lang="ts">
+  import { Link } from '@inertiajs/svelte'
+
+  export let foo: string
+  export let bar: string
+</script>
+
+<p id="foo">Foo: {foo}</p>
+<p id="bar">Bar: {bar}</p>
+<Link href="/once-props/ttl/a">Go to TTL Page A</Link>
diff --git a/packages/vue3/test-app/Pages/OnceProps/CustomKeyPageA.vue b/packages/vue3/test-app/Pages/OnceProps/CustomKeyPageA.vue
new file mode 100644
index 000000000..5209d79b1
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/CustomKeyPageA.vue
@@ -0,0 +1,11 @@
+<script setup lang="ts">
+import { Link } from '@inertiajs/vue3'
+
+defineProps<{ userPermissions: string; bar: string }>()
+</script>
+
+<template>
+  <p id="permissions">Permissions: {{ userPermissions }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+  <Link href="/once-props/custom-key/b">Go to Custom Key Page B</Link>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/CustomKeyPageB.vue b/packages/vue3/test-app/Pages/OnceProps/CustomKeyPageB.vue
new file mode 100644
index 000000000..daacbd17e
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/CustomKeyPageB.vue
@@ -0,0 +1,11 @@
+<script setup lang="ts">
+import { Link } from '@inertiajs/vue3'
+
+defineProps<{ permissions: string; bar: string }>()
+</script>
+
+<template>
+  <p id="permissions">Permissions: {{ permissions }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+  <Link href="/once-props/custom-key/a">Go to Custom Key Page A</Link>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/DeferredPageA.vue b/packages/vue3/test-app/Pages/OnceProps/DeferredPageA.vue
new file mode 100644
index 000000000..0116cb10e
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/DeferredPageA.vue
@@ -0,0 +1,23 @@
+<script setup lang="ts">
+import { Deferred, Link } from '@inertiajs/vue3'
+
+defineProps<{
+  foo?: { text: string }
+  bar: string
+}>()
+</script>
+
+<template>
+  <Deferred data="foo">
+    <template #fallback>
+      <div>Loading foo...</div>
+    </template>
+
+    <p id="foo">Foo: {{ foo?.text }}</p>
+  </Deferred>
+
+  <p id="bar">Bar: {{ bar }}</p>
+
+  <Link href="/once-props/deferred/b">Go to Deferred Page B</Link>
+  <Link href="/once-props/deferred/c" prefetch="mount">Go to Deferred Page C</Link>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/DeferredPageB.vue b/packages/vue3/test-app/Pages/OnceProps/DeferredPageB.vue
new file mode 100644
index 000000000..5b872324a
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/DeferredPageB.vue
@@ -0,0 +1,22 @@
+<script setup lang="ts">
+import { Deferred, Link } from '@inertiajs/vue3'
+
+defineProps<{
+  foo?: { text: string }
+  bar: string
+}>()
+</script>
+
+<template>
+  <Deferred data="foo">
+    <template #fallback>
+      <div>Loading foo...</div>
+    </template>
+
+    <p id="foo">Foo: {{ foo?.text }}</p>
+  </Deferred>
+
+  <p id="bar">Bar: {{ bar }}</p>
+
+  <Link href="/once-props/deferred/a">Go to Deferred Page A</Link>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/DeferredPageC.vue b/packages/vue3/test-app/Pages/OnceProps/DeferredPageC.vue
new file mode 100644
index 000000000..5b872324a
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/DeferredPageC.vue
@@ -0,0 +1,22 @@
+<script setup lang="ts">
+import { Deferred, Link } from '@inertiajs/vue3'
+
+defineProps<{
+  foo?: { text: string }
+  bar: string
+}>()
+</script>
+
+<template>
+  <Deferred data="foo">
+    <template #fallback>
+      <div>Loading foo...</div>
+    </template>
+
+    <p id="foo">Foo: {{ foo?.text }}</p>
+  </Deferred>
+
+  <p id="bar">Bar: {{ bar }}</p>
+
+  <Link href="/once-props/deferred/a">Go to Deferred Page A</Link>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/MergePageA.vue b/packages/vue3/test-app/Pages/OnceProps/MergePageA.vue
new file mode 100644
index 000000000..456d85d3b
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/MergePageA.vue
@@ -0,0 +1,12 @@
+<script setup lang="ts">
+import { Link, router } from '@inertiajs/vue3'
+
+defineProps<{ items: string[]; bar: string }>()
+</script>
+
+<template>
+  <p id="items">Items count: {{ items.length }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+  <Link href="/once-props/merge/b">Go to Merge Page B</Link>
+  <button @click="router.reload({ only: ['items'] })">Load more items</button>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/MergePageB.vue b/packages/vue3/test-app/Pages/OnceProps/MergePageB.vue
new file mode 100644
index 000000000..5450f8424
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/MergePageB.vue
@@ -0,0 +1,12 @@
+<script setup lang="ts">
+import { Link, router } from '@inertiajs/vue3'
+
+defineProps<{ items: string[]; bar: string }>()
+</script>
+
+<template>
+  <p id="items">Items count: {{ items.length }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+  <Link href="/once-props/merge/a">Go to Merge Page A</Link>
+  <button @click="router.reload({ only: ['items'] })">Load more items</button>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/OptionalPageA.vue b/packages/vue3/test-app/Pages/OnceProps/OptionalPageA.vue
new file mode 100644
index 000000000..854de286a
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/OptionalPageA.vue
@@ -0,0 +1,12 @@
+<script setup lang="ts">
+import { Link, router } from '@inertiajs/vue3'
+
+defineProps<{ foo?: string; bar: string }>()
+</script>
+
+<template>
+  <p id="foo">Foo: {{ foo ?? 'not loaded' }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+  <Link href="/once-props/optional/b">Go to Optional Page B</Link>
+  <button @click="router.reload({ only: ['foo'] })">Load foo</button>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/OptionalPageB.vue b/packages/vue3/test-app/Pages/OnceProps/OptionalPageB.vue
new file mode 100644
index 000000000..b983964f7
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/OptionalPageB.vue
@@ -0,0 +1,12 @@
+<script setup lang="ts">
+import { Link, router } from '@inertiajs/vue3'
+
+defineProps<{ foo?: string; bar: string }>()
+</script>
+
+<template>
+  <p id="foo">Foo: {{ foo ?? 'not loaded' }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+  <Link href="/once-props/optional/a">Go to Optional Page A</Link>
+  <button @click="router.reload({ only: ['foo'] })">Load foo</button>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/PageA.vue b/packages/vue3/test-app/Pages/OnceProps/PageA.vue
new file mode 100644
index 000000000..087d78cd7
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/PageA.vue
@@ -0,0 +1,16 @@
+<script setup lang="ts">
+import { Link, router } from '@inertiajs/vue3'
+
+defineProps<{ foo: string; bar: string }>()
+</script>
+
+<template>
+  <p id="foo">Foo: {{ foo }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+  <Link href="/once-props/page-b">Go to Page B</Link>
+  <Link href="/once-props/page-c">Go to Page C</Link>
+  <Link href="/once-props/page-d" prefetch="mount">Go to Page D</Link>
+  <Link href="/once-props/page-e" prefetch="mount" :cacheFor="1000">Go to Page E (short cache)</Link>
+  <button @click="router.reload({ only: ['foo'] })">Reload (only foo)</button>
+  <button @click="router.replaceProp('foo', 'replaced-foo')">Replace foo</button>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/PageB.vue b/packages/vue3/test-app/Pages/OnceProps/PageB.vue
new file mode 100644
index 000000000..9e8dc01a9
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/PageB.vue
@@ -0,0 +1,12 @@
+<script setup lang="ts">
+import { Link, router } from '@inertiajs/vue3'
+
+defineProps<{ foo: string; bar: string }>()
+</script>
+
+<template>
+  <p id="foo">Foo: {{ foo }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+  <Link href="/once-props/page-a">Go to Page A</Link>
+  <button @click="router.reload({ only: ['foo'] })">Reload (only foo)</button>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/PageC.vue b/packages/vue3/test-app/Pages/OnceProps/PageC.vue
new file mode 100644
index 000000000..2d4cc8a92
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/PageC.vue
@@ -0,0 +1,9 @@
+<script setup lang="ts">
+import { Link } from '@inertiajs/vue3'
+</script>
+
+<template>
+  <Link href="/once-props/page-a">Go to Page A</Link>
+  <Link href="/once-props/page-b">Go to Page B</Link>
+  <Link href="/once-props/page-d" prefetch="mount">Go to Page D</Link>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/PageD.vue b/packages/vue3/test-app/Pages/OnceProps/PageD.vue
new file mode 100644
index 000000000..8e9a9b6b4
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/PageD.vue
@@ -0,0 +1,8 @@
+<script setup lang="ts">
+defineProps<{ foo: string; bar: string }>()
+</script>
+
+<template>
+  <p id="foo">Foo: {{ foo }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/PageE.vue b/packages/vue3/test-app/Pages/OnceProps/PageE.vue
new file mode 100644
index 000000000..8e9a9b6b4
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/PageE.vue
@@ -0,0 +1,8 @@
+<script setup lang="ts">
+defineProps<{ foo: string; bar: string }>()
+</script>
+
+<template>
+  <p id="foo">Foo: {{ foo }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/TtlPageA.vue b/packages/vue3/test-app/Pages/OnceProps/TtlPageA.vue
new file mode 100644
index 000000000..f74ce16e1
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/TtlPageA.vue
@@ -0,0 +1,13 @@
+<script setup lang="ts">
+import { Link, router } from '@inertiajs/vue3'
+
+defineProps<{ foo: string; bar: string }>()
+</script>
+
+<template>
+  <p id="foo">Foo: {{ foo }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+  <Link href="/once-props/ttl/b">Go to TTL Page B</Link>
+  <Link href="/once-props/ttl/c" prefetch="mount">Go to TTL Page C</Link>
+  <button @click="router.reload({ only: ['foo'] })">Reload foo</button>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/TtlPageB.vue b/packages/vue3/test-app/Pages/OnceProps/TtlPageB.vue
new file mode 100644
index 000000000..85e539028
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/TtlPageB.vue
@@ -0,0 +1,11 @@
+<script setup lang="ts">
+import { Link } from '@inertiajs/vue3'
+
+defineProps<{ foo: string; bar: string }>()
+</script>
+
+<template>
+  <p id="foo">Foo: {{ foo }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+  <Link href="/once-props/ttl/a">Go to TTL Page A</Link>
+</template>
diff --git a/packages/vue3/test-app/Pages/OnceProps/TtlPageC.vue b/packages/vue3/test-app/Pages/OnceProps/TtlPageC.vue
new file mode 100644
index 000000000..85e539028
--- /dev/null
+++ b/packages/vue3/test-app/Pages/OnceProps/TtlPageC.vue
@@ -0,0 +1,11 @@
+<script setup lang="ts">
+import { Link } from '@inertiajs/vue3'
+
+defineProps<{ foo: string; bar: string }>()
+</script>
+
+<template>
+  <p id="foo">Foo: {{ foo }}</p>
+  <p id="bar">Bar: {{ bar }}</p>
+  <Link href="/once-props/ttl/a">Go to TTL Page A</Link>
+</template>
diff --git a/tests/app/server.js b/tests/app/server.js
index a5371ae34..43e5fe10b 100644
--- a/tests/app/server.js
+++ b/tests/app/server.js
@@ -1421,6 +1421,168 @@ app.post('/view-transition/form-errors', (req, res) =>
   }),
 )
 
+const getOncePropsData = (req, prop = 'foo') => {
+  const isInertiaRequest = !!req.headers['x-inertia']
+  const partialData = req.headers['x-inertia-partial-data']?.split(',') ?? []
+  const loadedOnceProps = req.headers['x-inertia-except-once-props']?.split(',') ?? []
+  const isPartialRequest = partialData.includes(prop)
+  const hasPropAlready = loadedOnceProps.includes(prop)
+  const shouldResolveProp = !isInertiaRequest || isPartialRequest || !hasPropAlready
+
+  return {
+    isInertiaRequest,
+    partialData,
+    loadedOnceProps,
+    isPartialRequest,
+    hasPropAlready,
+    shouldResolveProp,
+  }
+}
+
+app.get('/once-props/page-a', (req, res) => {
+  const { shouldResolveProp } = getOncePropsData(req)
+
+  inertia.render(req, res, {
+    component: 'OnceProps/PageA',
+    props: {
+      foo: shouldResolveProp ? 'foo-a-' + Date.now() : undefined,
+      bar: 'bar-a',
+    },
+    onceProps: { foo: { prop: 'foo', expiresAt: null } },
+  })
+})
+
+app.get('/once-props/page-b', (req, res) => {
+  const { shouldResolveProp } = getOncePropsData(req)
+
+  inertia.render(req, res, {
+    component: 'OnceProps/PageB',
+    props: {
+      foo: shouldResolveProp ? 'foo-b-' + Date.now() : undefined,
+      bar: 'bar-b',
+    },
+    onceProps: { foo: { prop: 'foo', expiresAt: null } },
+  })
+})
+
+app.get('/once-props/page-c', (req, res) => {
+  inertia.render(req, res, {
+    component: 'OnceProps/PageC',
+  })
+})
+
+app.get('/once-props/page-d', (req, res) => {
+  const { shouldResolveProp } = getOncePropsData(req)
+
+  inertia.render(req, res, {
+    component: 'OnceProps/PageD',
+    props: {
+      foo: shouldResolveProp ? 'foo-d-' + Date.now() : undefined,
+      bar: 'bar-d',
+    },
+    onceProps: { foo: { prop: 'foo', expiresAt: null } },
+  })
+})
+
+app.get('/once-props/page-e', (req, res) => {
+  const { shouldResolveProp } = getOncePropsData(req)
+
+  inertia.render(req, res, {
+    component: 'OnceProps/PageE',
+    props: {
+      foo: shouldResolveProp ? 'foo-e-' + Date.now() : undefined,
+      bar: 'bar-e',
+    },
+    onceProps: { foo: { prop: 'foo', expiresAt: null } },
+  })
+})
+
+app.get('/once-props/deferred/:page', (req, res) => {
+  const { isPartialRequest, hasPropAlready } = getOncePropsData(req)
+  const page = req.params.page
+
+  if (isPartialRequest) {
+    return setTimeout(() => {
+      inertia.render(req, res, {
+        component: `OnceProps/DeferredPage${page.toUpperCase()}`,
+        props: {
+          foo: { text: `foo-${page}-` + Date.now() },
+          bar: `bar-${page}`,
+        },
+        onceProps: { foo: { prop: 'foo', expiresAt: null } },
+      })
+    }, 100)
+  }
+
+  inertia.render(req, res, {
+    component: `OnceProps/DeferredPage${page.toUpperCase()}`,
+    props: {
+      bar: `bar-${page}`,
+    },
+    deferredProps: hasPropAlready ? {} : { default: ['foo'] },
+    onceProps: { foo: { prop: 'foo', expiresAt: null } },
+  })
+})
+
+app.get('/once-props/ttl/:page', (req, res) => {
+  const { shouldResolveProp } = getOncePropsData(req)
+  const page = req.params.page
+  const expiresAt = Date.now() + 2000
+
+  inertia.render(req, res, {
+    component: `OnceProps/TtlPage${page.toUpperCase()}`,
+    props: {
+      foo: shouldResolveProp ? `foo-${page}-` + Date.now() : undefined,
+      bar: `bar-${page}`,
+    },
+    onceProps: { foo: { prop: 'foo', expiresAt } },
+  })
+})
+
+app.get('/once-props/optional/:page', (req, res) => {
+  const { isPartialRequest, hasPropAlready } = getOncePropsData(req)
+  const page = req.params.page
+
+  inertia.render(req, res, {
+    component: `OnceProps/OptionalPage${page.toUpperCase()}`,
+    props: {
+      foo: isPartialRequest ? `foo-${page}-` + Date.now() : undefined,
+      bar: `bar-${page}`,
+    },
+    onceProps: isPartialRequest || hasPropAlready ? { foo: { prop: 'foo', expiresAt: null } } : {},
+  })
+})
+
+app.get('/once-props/merge/:page', (req, res) => {
+  const { shouldResolveProp } = getOncePropsData(req, 'items')
+  const page = req.params.page
+
+  inertia.render(req, res, {
+    component: `OnceProps/MergePage${page.toUpperCase()}`,
+    props: {
+      items: shouldResolveProp ? new Array(3).fill(page) : undefined,
+      bar: `bar-${page}`,
+    },
+    mergeProps: ['items'],
+    onceProps: { items: { prop: 'items', expiresAt: null } },
+  })
+})
+
+app.get('/once-props/custom-key/:page', (req, res) => {
+  const page = req.params.page
+  const propName = page === 'a' ? 'userPermissions' : 'permissions'
+  const { shouldResolveProp } = getOncePropsData(req, 'user-permissions')
+
+  inertia.render(req, res, {
+    component: `OnceProps/CustomKeyPage${page.toUpperCase()}`,
+    props: {
+      [propName]: shouldResolveProp ? `perms-${page}-` + Date.now() : undefined,
+      bar: `bar-${page}`,
+    },
+    onceProps: { 'user-permissions': { prop: propName, expiresAt: null } },
+  })
+})
+
 app.all('*page', (req, res) => inertia.render(req, res))
 
 // Send errors to the console (instead of crashing the server)
diff --git a/tests/once-props.spec.ts b/tests/once-props.spec.ts
new file mode 100644
index 000000000..3de695c68
--- /dev/null
+++ b/tests/once-props.spec.ts
@@ -0,0 +1,442 @@
+import { expect, test } from '@playwright/test'
+import { clickAndWaitForResponse } from './support'
+
+test.beforeEach(async ({ page }) => {
+  await page.goto('/once-props/page-a')
+})
+
+test('loads the prop on initial page load and then preserves it after navigation', async ({ page }) => {
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  await expect(page.getByText('Bar: bar-a')).toBeVisible()
+
+  await page.getByRole('link', { name: 'Go to Page B' }).click()
+
+  await expect(page).toHaveURL('/once-props/page-b')
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+
+  await page.reload()
+
+  await expect(page).toHaveURL('/once-props/page-b')
+  await expect(page.getByText('Foo: foo-b')).toBeVisible()
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+})
+
+test('navigating back and forward preserves the prop', async ({ page }) => {
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  await expect(page.getByText('Bar: bar-a')).toBeVisible()
+
+  await page.getByRole('link', { name: 'Go to Page B' }).click()
+
+  await expect(page).toHaveURL('/once-props/page-b')
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+
+  await page.goBack()
+
+  await expect(page).toHaveURL('/once-props/page-a')
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  await expect(page.getByText('Bar: bar-a')).toBeVisible()
+
+  await page.goForward()
+
+  await expect(page).toHaveURL('/once-props/page-b')
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+})
+
+test('partial reload preserves the prop', async ({ page }) => {
+  const fooText = await page.locator('#foo').innerText()
+
+  await page.getByRole('button', { name: 'Reload (only foo)' }).click()
+  await expect(page.getByText(fooText)).not.toBeVisible()
+
+  const newFooText = await page.locator('#foo').innerText()
+
+  expect(newFooText.startsWith('Foo: foo-a')).toBe(true)
+  expect(newFooText).not.toBe(fooText)
+
+  await page.getByRole('link', { name: 'Go to Page B' }).click()
+
+  await expect(page).toHaveURL('/once-props/page-b')
+  await expect(page.getByText(newFooText)).toBeVisible()
+})
+
+test('navigating through an intermediary page without the once prop', async ({ page }) => {
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  await expect(page.getByText('Bar: bar-a')).toBeVisible()
+
+  await page.getByRole('link', { name: 'Go to Page C' }).click()
+
+  await expect(page).toHaveURL('/once-props/page-c')
+
+  await page.getByRole('link', { name: 'Go to Page B' }).click()
+
+  await expect(page).toHaveURL('/once-props/page-b')
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+  await expect(page.getByText('Foo: foo-b')).toBeVisible()
+})
+
+test('deferred once prop is loaded via defer and then remembered on navigation', async ({ page }) => {
+  await page.goto('/once-props/deferred/a')
+
+  await expect(page.getByText('Loading foo...')).toBeVisible()
+  await expect(page.getByText('Bar: bar-a')).toBeVisible()
+
+  await page.waitForResponse(
+    (response) =>
+      response.url().includes('/once-props/deferred/a') &&
+      response.request().headers()['x-inertia-partial-data'] === 'foo',
+  )
+
+  await expect(page.getByText('Loading foo...')).not.toBeVisible()
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+
+  const fooText = await page.locator('#foo').innerText()
+
+  await clickAndWaitForResponse(page, 'Go to Deferred Page B', '/once-props/deferred/b')
+
+  await expect(page).toHaveURL('/once-props/deferred/b')
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+  await expect(page.getByText('Loading foo...')).not.toBeVisible()
+  await expect(page.getByText(fooText)).toBeVisible()
+})
+
+test('once prop with TTL is remembered within TTL window and reloaded after expiry', async ({ page }) => {
+  await page.goto('/once-props/ttl/a')
+
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  await expect(page.getByText('Bar: bar-a')).toBeVisible()
+
+  const initialFooText = await page.locator('#foo').innerText()
+
+  await page.getByRole('link', { name: 'Go to TTL Page B' }).click()
+
+  await expect(page).toHaveURL('/once-props/ttl/b')
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+  await expect(page.getByText(initialFooText)).toBeVisible()
+
+  await page.getByRole('link', { name: 'Go to TTL Page A' }).click()
+
+  await expect(page).toHaveURL('/once-props/ttl/a')
+  await expect(page.getByText(initialFooText)).toBeVisible()
+
+  await page.waitForTimeout(2500)
+
+  await page.getByRole('link', { name: 'Go to TTL Page B' }).click()
+
+  await expect(page).toHaveURL('/once-props/ttl/b')
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+
+  const newFooText = await page.locator('#foo').innerText()
+  expect(newFooText).not.toBe(initialFooText)
+  expect(newFooText.startsWith('Foo: foo-b')).toBe(true)
+})
+
+test('once prop with TTL has its expiry reset after reload', async ({ page }) => {
+  await page.goto('/once-props/ttl/a')
+
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  const initialFooText = await page.locator('#foo').innerText()
+
+  await page.waitForTimeout(2500)
+
+  await page.getByRole('button', { name: 'Reload foo' }).click()
+  await expect(page.getByText(initialFooText)).not.toBeVisible()
+
+  const reloadedFooText = await page.locator('#foo').innerText()
+  expect(reloadedFooText).not.toBe(initialFooText)
+  expect(reloadedFooText.startsWith('Foo: foo-a')).toBe(true)
+
+  await page.getByRole('link', { name: 'Go to TTL Page B' }).click()
+
+  await expect(page).toHaveURL('/once-props/ttl/b')
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+  await expect(page.getByText(reloadedFooText)).toBeVisible()
+})
+
+test('once prop TTL is preserved across navigation and expires correctly', async ({ page }) => {
+  await page.goto('/once-props/ttl/a')
+
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  const initialFooText = await page.locator('#foo').innerText()
+
+  await page.waitForTimeout(1000)
+
+  await page.getByRole('link', { name: 'Go to TTL Page B' }).click()
+  await expect(page).toHaveURL('/once-props/ttl/b')
+  await expect(page.getByText(initialFooText)).toBeVisible()
+
+  await page.waitForTimeout(1500)
+
+  await page.getByRole('link', { name: 'Go to TTL Page A' }).click()
+  await expect(page).toHaveURL('/once-props/ttl/a')
+
+  const newFooText = await page.locator('#foo').innerText()
+  expect(newFooText).not.toBe(initialFooText)
+  expect(newFooText.startsWith('Foo: foo-a')).toBe(true)
+})
+
+test('optional once prop is not loaded initially, fetched via reload, then cached on navigation', async ({ page }) => {
+  await page.goto('/once-props/optional/a')
+
+  await expect(page.getByText('Foo: not loaded')).toBeVisible()
+  await expect(page.getByText('Bar: bar-a')).toBeVisible()
+
+  await clickAndWaitForResponse(page, 'Load foo', '/once-props/optional/a', 'button')
+
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+
+  const fooText = await page.locator('#foo').innerText()
+  expect(fooText.startsWith('Foo: foo-a')).toBe(true)
+
+  await clickAndWaitForResponse(page, 'Go to Optional Page B', '/once-props/optional/b')
+
+  await expect(page).toHaveURL('/once-props/optional/b')
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+  await expect(page.getByText(fooText)).toBeVisible()
+
+  await clickAndWaitForResponse(page, 'Go to Optional Page A', '/once-props/optional/a')
+
+  await expect(page).toHaveURL('/once-props/optional/a')
+  await expect(page.getByText(fooText)).toBeVisible()
+})
+
+test('merge once prop merges on reload and preserves merged data on navigation', async ({ page }) => {
+  await page.goto('/once-props/merge/a')
+
+  await expect(page.getByText('Items count: 3')).toBeVisible()
+  await expect(page.getByText('Bar: bar-a')).toBeVisible()
+
+  await clickAndWaitForResponse(page, 'Load more items', '/once-props/merge/a', 'button')
+
+  await expect(page.getByText('Items count: 6')).toBeVisible()
+
+  await clickAndWaitForResponse(page, 'Go to Merge Page B', '/once-props/merge/b')
+
+  await expect(page).toHaveURL('/once-props/merge/b')
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+  await expect(page.getByText('Items count: 6')).toBeVisible()
+
+  await clickAndWaitForResponse(page, 'Go to Merge Page A', '/once-props/merge/a')
+
+  await expect(page).toHaveURL('/once-props/merge/a')
+  await expect(page.getByText('Items count: 6')).toBeVisible()
+})
+
+test('once prop with custom key shares data across pages with different prop names', async ({ page }) => {
+  await page.goto('/once-props/custom-key/a')
+
+  await expect(page.getByText('Permissions: perms-a')).toBeVisible()
+  await expect(page.getByText('Bar: bar-a')).toBeVisible()
+
+  const permissionsText = await page.locator('#permissions').innerText()
+
+  await page.getByRole('link', { name: 'Go to Custom Key Page B' }).click()
+
+  await expect(page).toHaveURL('/once-props/custom-key/b')
+  await expect(page.getByText('Bar: bar-b')).toBeVisible()
+  await expect(page.getByText(permissionsText)).toBeVisible()
+
+  await page.getByRole('link', { name: 'Go to Custom Key Page A' }).click()
+
+  await expect(page).toHaveURL('/once-props/custom-key/a')
+  await expect(page.getByText(permissionsText)).toBeVisible()
+})
+
+test('prefetched once prop is preserved after navigating through intermediary page', async ({ page }) => {
+  const prefetchPromise = page.waitForResponse((response) => response.url().includes('/once-props/page-d'))
+
+  await page.goto('/once-props/page-a')
+
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  await expect(page.getByText('Bar: bar-a')).toBeVisible()
+
+  const fooText = await page.locator('#foo').innerText()
+
+  await prefetchPromise
+
+  await page.getByRole('link', { name: 'Go to Page C' }).click()
+  await expect(page).toHaveURL('/once-props/page-c')
+
+  await page.getByRole('link', { name: 'Go to Page D' }).click()
+  await expect(page).toHaveURL('/once-props/page-d')
+
+  await expect(page.getByText(fooText)).toBeVisible()
+})
+
+test('prefetched once prop is updated when re-prefetched before use', async ({ page }) => {
+  const prefetchPromise = page.waitForResponse((response) => response.url().includes('/once-props/page-d'))
+
+  await page.goto('/once-props/page-a')
+
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  await expect(page.getByText('Bar: bar-a')).toBeVisible()
+
+  const fooText = await page.locator('#foo').innerText()
+
+  await prefetchPromise
+
+  await page.getByRole('button', { name: 'Reload (only foo)' }).click()
+  await expect(page.getByText(fooText)).not.toBeVisible()
+
+  const newFooText = await page.locator('#foo').innerText()
+
+  expect(newFooText.startsWith('Foo: foo-a')).toBe(true)
+  expect(newFooText).not.toBe(fooText)
+
+  await page.getByRole('link', { name: 'Go to Page D' }).click()
+  await expect(page).toHaveURL('/once-props/page-d')
+
+  await expect(page.getByText(newFooText)).toBeVisible()
+})
+
+test('prefetch cache TTL is extended when once prop is reloaded before expiry', async ({ page }) => {
+  const prefetchPromise = page.waitForResponse((response) => response.url().includes('/once-props/ttl/c'))
+
+  await page.goto('/once-props/ttl/a')
+
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  const initialFooText = await page.locator('#foo').innerText()
+
+  await prefetchPromise
+
+  await page.getByRole('button', { name: 'Reload foo' }).click()
+  await expect(page.getByText(initialFooText)).not.toBeVisible()
+
+  const reloadedFooText = await page.locator('#foo').innerText()
+
+  await page.waitForTimeout(1500)
+
+  let requestMade = false
+  page.on('request', (request) => {
+    if (request.url().includes('/once-props/ttl/c')) {
+      requestMade = true
+    }
+  })
+
+  await page.getByRole('link', { name: 'Go to TTL Page C' }).click()
+  await expect(page).toHaveURL('/once-props/ttl/c')
+
+  expect(requestMade).toBe(false)
+  await expect(page.getByText(reloadedFooText)).toBeVisible()
+})
+
+test('prefetch cache is invalidated when extended TTL expires', async ({ page }) => {
+  test.setTimeout(10000)
+  const prefetchPromise = page.waitForResponse((response) => response.url().includes('/once-props/ttl/c'))
+
+  await page.goto('/once-props/ttl/a')
+
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  const initialFooText = await page.locator('#foo').innerText()
+
+  await prefetchPromise
+
+  await page.getByRole('button', { name: 'Reload foo' }).click()
+  await expect(page.getByText(initialFooText)).not.toBeVisible()
+
+  const reloadedFooText = await page.locator('#foo').innerText()
+
+  await page.waitForTimeout(2500)
+
+  await page.getByRole('link', { name: 'Go to TTL Page C' }).click()
+  await expect(page).toHaveURL('/once-props/ttl/c')
+
+  const newFooText = await page.locator('#foo').innerText()
+  expect(newFooText).not.toBe(reloadedFooText)
+  expect(newFooText.startsWith('Foo: foo-c')).toBe(true)
+})
+
+test('prefetched once prop with TTL is refreshed after expiry', async ({ page }) => {
+  const prefetchPromise = page.waitForResponse((response) => response.url().includes('/once-props/ttl/c'))
+
+  await page.goto('/once-props/ttl/a')
+
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  const initialFooText = await page.locator('#foo').innerText()
+
+  await prefetchPromise
+  await page.waitForTimeout(2500)
+
+  await page.getByRole('link', { name: 'Go to TTL Page C' }).click()
+  await expect(page).toHaveURL('/once-props/ttl/c')
+
+  const newFooText = await page.locator('#foo').innerText()
+  expect(newFooText).not.toBe(initialFooText)
+  expect(newFooText.startsWith('Foo: foo-c')).toBe(true)
+})
+
+test('prefetch cache is updated when deferred once prop finishes loading', async ({ page }) => {
+  const prefetchPromise = page.waitForResponse(
+    (response) =>
+      response.url().includes('/once-props/deferred/c') && !response.request().headers()['x-inertia-partial-data'],
+  )
+
+  await page.goto('/once-props/deferred/a')
+
+  await expect(page.getByText('Loading foo...')).toBeVisible()
+
+  await prefetchPromise
+
+  await page.waitForResponse(
+    (response) =>
+      response.url().includes('/once-props/deferred/a') &&
+      response.request().headers()['x-inertia-partial-data'] === 'foo',
+  )
+
+  await expect(page.getByText('Loading foo...')).not.toBeVisible()
+  const fooText = await page.locator('#foo').innerText()
+  expect(fooText.startsWith('Foo: foo-a')).toBe(true)
+
+  await page.getByRole('link', { name: 'Go to Deferred Page C' }).click()
+  await expect(page).toHaveURL('/once-props/deferred/c')
+
+  await expect(page.getByText(fooText)).toBeVisible()
+})
+
+test('prefetch cache is updated when replaceProp is called', async ({ page }) => {
+  const prefetchPromise = page.waitForResponse((response) => response.url().includes('/once-props/page-d'))
+
+  await page.goto('/once-props/page-a')
+
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+
+  await prefetchPromise
+
+  await page.getByRole('button', { name: 'Replace foo' }).click()
+
+  await expect(page.getByText('Foo: replaced-foo')).toBeVisible()
+
+  await page.getByRole('link', { name: 'Go to Page D' }).click()
+  await expect(page).toHaveURL('/once-props/page-d')
+
+  await expect(page.getByText('Foo: replaced-foo')).toBeVisible()
+})
+
+test('prefetch cache expires based on cacheFor even when once prop has no TTL', async ({ page }) => {
+  const prefetchPromise = page.waitForResponse((response) => response.url().includes('/once-props/page-e'))
+
+  await page.goto('/once-props/page-a')
+
+  await expect(page.getByText('Foo: foo-a')).toBeVisible()
+  const fooText = await page.locator('#foo').innerText()
+
+  await prefetchPromise
+
+  await page.waitForTimeout(1500)
+
+  let requestMade = false
+  page.on('request', (request) => {
+    if (request.url().includes('/once-props/page-e')) {
+      requestMade = true
+    }
+  })
+
+  await page.getByRole('link', { name: 'Go to Page E (short cache)' }).click()
+  await expect(page).toHaveURL('/once-props/page-e')
+
+  expect(requestMade).toBe(true)
+  await expect(page.getByText('Bar: bar-e')).toBeVisible()
+  await expect(page.getByText(fooText)).toBeVisible()
+})