diff --git a/frontend/src/lib/components/sessions/sessionMirror.svelte.ts b/frontend/src/lib/components/sessions/sessionMirror.svelte.ts
index f30d66ca45..657f120e98 100644
--- a/frontend/src/lib/components/sessions/sessionMirror.svelte.ts
+++ b/frontend/src/lib/components/sessions/sessionMirror.svelte.ts
@@ -998,9 +998,23 @@ async function flush(): Promise<void> {
 		let settledAny = false
 		let leftForNext = false
 		for (const [ws, w] of work) {
-			const out = await pushWorkspace(ws, w, email)
-			if (out.status === 'abort') return
-			if (out.status === 'off') {
+			// A push carries whole transcripts, and a workspace that keeps no backups is
+			// asked again on every page load: one this page has not heard from yet is asked
+			// with the listing first, which costs nothing to refuse.
+			let probe: 'on' | 'off' | 'failed' = 'on'
+			if (!wsState.has(ws)) {
+				const listing = await fetchListing(ws)
+				if (getCurrentUserEmail() !== email) return
+				probe = listing === 'off' || listing === 'failed' ? listing : 'on'
+				if (probe === 'on') wsState.set(ws, 'on')
+			}
+			if (probe === 'failed') {
+				backOff()
+				continue
+			}
+			const out = probe === 'off' ? undefined : await pushWorkspace(ws, w, email)
+			if (out?.status === 'abort') return
+			if (!out || out.status === 'off') {
 				markOff(ws)
 				await staleWorkspaceSync(ws, email)
 				// Same rule as the loop above: a removal is worth keeping only for a session
@@ -1189,22 +1203,28 @@ function unpackBackup(
 
 type BackupListing = Awaited<ReturnType<typeof AiService.listAiSessionBackups>>
 
-/** The workspace's listing; `off` when it keeps no backups, `failed` when it could not be
- * listed this time. */
-async function listWorkspace(ws: string, email: string): Promise<BackupListing | 'off' | 'failed'> {
+/** The workspace's listing as the server answers it; `off` when it keeps no backups,
+ * `failed` when it could not be listed this time. */
+async function fetchListing(ws: string): Promise<BackupListing | 'off' | 'failed'> {
 	let listing
 	try {
 		listing = await AiService.listAiSessionBackups({ workspace: ws })
 	} catch (e) {
 		const status = statusOf(e)
-		if (status === 404 || status === 403) {
-			markOff(ws)
-			return 'off'
-		}
+		// 404: a build without object storage, or a storage whose resource is gone.
+		// 403: nothing this token may back up.
+		if (status === 404 || status === 403) return 'off'
 		console.warn('Could not list session backups', e)
 		return 'failed'
 	}
-	if (!listing.enabled) {
+	return listing.enabled ? listing : 'off'
+}
+
+/** `fetchListing`, with what it says of the workspace recorded for the page. */
+async function listWorkspace(ws: string, email: string): Promise<BackupListing | 'off' | 'failed'> {
+	const listing = await fetchListing(ws)
+	if (listing === 'failed') return 'failed'
+	if (listing === 'off') {
 		markOff(ws)
 		return 'off'
 	}
diff --git a/frontend/src/lib/components/sessions/sessionMirror.test.ts b/frontend/src/lib/components/sessions/sessionMirror.test.ts
index 55a1acc138..9a8a211ded 100644
--- a/frontend/src/lib/components/sessions/sessionMirror.test.ts
+++ b/frontend/src/lib/components/sessions/sessionMirror.test.ts
@@ -150,6 +150,7 @@ beforeEach(async () => {
 	__resetMirrorForTesting()
 	pushMock.mockReset()
 	listMock.mockReset()
+	listMock.mockResolvedValue({ enabled: true, sessions: [] })
 	pullMock.mockReset()
 	chatImport.unavailable = false
 	chatImport.pruneFails = false
@@ -316,6 +317,30 @@ describe('sessionMirror flush', () => {
 		expect((await __syncRowsForTesting(EMAIL)).some((r) => r.id === 'sr')).toBe(false)
 	})
 
+	it('asks a workspace it has not heard from before sending it a transcript', async () => {
+		const s: Session = { id: 'sp', name: 'session-1', createdAt: 1, workspace_id: 'ws' }
+		sessionState.sessions = [s]
+		await putSession(s)
+		const { ApiError } = await import('$lib/gen')
+		listMock.mockRejectedValueOnce(
+			new ApiError({ method: 'GET', url: '' } as never, { status: 404 } as never, 'no resource')
+		)
+		await __flushForTesting()
+		expect(listMock).toHaveBeenCalledTimes(1)
+		expect(pushMock).not.toHaveBeenCalled()
+		expect(await pendingDirty()).toEqual(['sp'])
+
+		// A page that heard the workspace keeps backups pushes without asking again.
+		__resetMirrorForTesting()
+		pushMock.mockResolvedValue({ enabled: true, results: [{ id: 'sp' }] })
+		await __flushForTesting()
+		await putSession({ ...s, summary: 'changed' })
+		await __flushForTesting()
+		expect(listMock).toHaveBeenCalledTimes(2)
+		expect(pushMock).toHaveBeenCalledTimes(2)
+		expect(await pendingDirty()).toEqual([])
+	})
+
 	it('keeps the marks when the push fails, and stops for a workspace without storage', async () => {
 		const s: Session = { id: 's2', name: 'session-2', createdAt: 1, workspace_id: 'ws' }
 		const never: Session = { id: 's2b', name: 'session-3', createdAt: 2, workspace_id: 'ws' }
@@ -355,11 +380,11 @@ describe('sessionMirror flush', () => {
 
 		// Backups an admin turns on again elsewhere are noticed once the page's memory of
 		// them being off expires, with nothing else prompting it: the removal goes then.
-		listMock.mockResolvedValue({ enabled: true, sessions: [] })
+		listMock.mockClear()
 		pushMock.mockResolvedValueOnce({ enabled: true, results: [{ id: 's2' }] })
 		await vi.waitFor(() => expect(pushMock).toHaveBeenCalledTimes(4), { timeout: 3000 })
 		expect(pushMock.mock.calls[3][0].requestBody.removed).toEqual(['s2'])
-		await vi.waitFor(() => expect(listMock).toHaveBeenCalledTimes(1))
+		await vi.waitFor(() => expect(listMock).toHaveBeenCalled())
 		await __settleForTesting()
 		expect(pendingKeys()).toEqual([])
 	})
@@ -426,7 +451,7 @@ describe('sessionMirror flush', () => {
 		await __flushForTesting()
 		expect(pushMock).toHaveBeenCalledTimes(2)
 
-		listMock.mockResolvedValue({ enabled: true, sessions: [] })
+		listMock.mockClear()
 		pushMock.mockResolvedValueOnce({ enabled: true, results: [{ id: 'so' }] })
 		usersWorkspaceStore.set({ email: EMAIL, workspaces: [] } as never)
 		backupSettingsChanged('ws')