diff --git a/src/main/ipc/pty-hidden-delivery-gate.test.ts b/src/main/ipc/pty-hidden-delivery-gate.test.ts
index e4358812d5b..5efb9899732 100644
--- a/src/main/ipc/pty-hidden-delivery-gate.test.ts
+++ b/src/main/ipc/pty-hidden-delivery-gate.test.ts
@@ -50,9 +50,9 @@ describe('pty hidden delivery gate', () => {
     expect(shouldSuppressHiddenRendererPtyView(PTY_ID, {})).toBe(true)
     setRendererPtyDeliveryInterest(PTY_ID, true)
     expect(shouldSuppressHiddenRendererPtyView(PTY_ID, {})).toBe(true)
-    expect(
-      shouldSuppressHiddenRendererPtyView(PTY_ID, { terminalHiddenDeliveryGate: false })
-    ).toBe(false)
+    expect(shouldSuppressHiddenRendererPtyView(PTY_ID, { terminalHiddenDeliveryGate: false })).toBe(
+      false
+    )
   })
 
   it('routes a suppressed PTY sidecar-only exactly while interest is registered', () => {
diff --git a/src/main/ipc/pty-hidden-delivery-gate.ts b/src/main/ipc/pty-hidden-delivery-gate.ts
index 25f53d915e5..3c318b280da 100644
--- a/src/main/ipc/pty-hidden-delivery-gate.ts
+++ b/src/main/ipc/pty-hidden-delivery-gate.ts
@@ -97,9 +97,7 @@ export function shouldDropHiddenRendererPtyData(
   id: string,
   settings: HiddenPtyDeliveryGateSettings | null | undefined
 ): boolean {
-  return (
-    shouldSuppressHiddenRendererPtyView(id, settings) && !deliveryInterestRendererPtys.has(id)
-  )
+  return shouldSuppressHiddenRendererPtyView(id, settings) && !deliveryInterestRendererPtys.has(id)
 }
 
 /** Bytes a sidecar still needs while the view is suppressed: sent, but flagged
diff --git a/src/preload/api-types.ts b/src/preload/api-types.ts
index 24555ca239e..19922310fba 100644
--- a/src/preload/api-types.ts
+++ b/src/preload/api-types.ts
@@ -1112,6 +1112,18 @@ export type PluginMarketplaceHostInstallPreview = {
   blockedByKillList?: { reason: string; advisoryUrl?: string }
 }
 
+export type PtyDataPayload = {
+  id: string
+  data: string
+  seq?: number
+  rawLength?: number
+  transformed?: boolean
+  background?: boolean
+  droppedOutput?: boolean
+  /** Hidden-gated bytes delivered to raw-byte sidecars without the view. */
+  sidecarOnly?: boolean
+}
+
 export type PreloadApi = {
   app: AppApi
   orcaProfiles: {
@@ -1618,20 +1630,7 @@ export type PreloadApi = {
       rendererDispatcherReadyForcedCount: number
     }>
     resetRendererDeliveryDebug: () => Promise<void>
-    onData: (
-      callback: (data: {
-        id: string
-        data: string
-        seq?: number
-        rawLength?: number
-        transformed?: boolean
-        background?: boolean
-        droppedOutput?: boolean
-        /** Hidden-gated bytes for raw-byte sidecars only; the view must not
-         *  render or reply to them (main answered their queries). */
-        sidecarOnly?: boolean
-      }) => void
-    ) => () => void
+    onData: (callback: (data: PtyDataPayload) => void) => () => void
     onReplay: (callback: (data: { id: string; data: string }) => void) => () => void
     /** Out-of-band main→renderer signal that renderer-bound bytes were
      *  dropped (hidden-delivery gate / pending cap); the pane restores from
diff --git a/src/preload/index.ts b/src/preload/index.ts
index 394dcfac7eb..bf349006354 100644
--- a/src/preload/index.ts
+++ b/src/preload/index.ts
@@ -222,7 +222,8 @@ import type {
   PluginHostInstallSource,
   PluginHostListEntry,
   PluginHostLogLine,
-  PreloadApi
+  PreloadApi,
+  PtyDataPayload
 } from './api-types'
 import type { AgentKind, LaunchSource, RequestKind } from '../shared/telemetry-events'
 import { createBrowserFindSubscriptions } from './browser-find-subscriptions'
@@ -1154,30 +1155,8 @@ const api = {
     getSize: (id: string): Promise<{ cols: number; rows: number } | null> =>
       ipcRenderer.invoke('pty:getSize', { id }),
 
-    onData: (
-      callback: (data: {
-        id: string
-        data: string
-        seq?: number
-        rawLength?: number
-        transformed?: boolean
-        background?: boolean
-        droppedOutput?: boolean
-      }) => void
-    ): (() => void) => {
-      const listener = (
-        _event: Electron.IpcRendererEvent,
-        data: {
-          id: string
-          data: string
-          seq?: number
-          rawLength?: number
-          transformed?: boolean
-          background?: boolean
-          droppedOutput?: boolean
-          sidecarOnly?: boolean
-        }
-      ) => callback(data)
+    onData: (callback: (data: PtyDataPayload) => void): (() => void) => {
+      const listener = (_event: Electron.IpcRendererEvent, data: PtyDataPayload) => callback(data)
       ipcRenderer.on('pty:data', listener)
       return () => ipcRenderer.removeListener('pty:data', listener)
     },
diff --git a/src/preload/pty-snapshot-capability-ipc.test.ts b/src/preload/pty-snapshot-capability-ipc.test.ts
index 5c639edcfb7..6760a61335a 100644
--- a/src/preload/pty-snapshot-capability-ipc.test.ts
+++ b/src/preload/pty-snapshot-capability-ipc.test.ts
@@ -69,4 +69,23 @@ describe('PTY snapshot capability preload IPC', () => {
       expect.anything()
     )
   })
+
+  it('forwards the sidecar-only PTY data bit through the public preload API', async () => {
+    await import('./index')
+    const api = exposeInMainWorld.mock.calls.find(([name]) => name === 'api')?.[1] as PreloadApi
+    const callback = vi.fn()
+    api.pty.onData(callback)
+    const listener = on.mock.calls.find(([channel]) => channel === 'pty:data')?.[1] as (
+      event: unknown,
+      payload: { id: string; data: string; sidecarOnly?: boolean }
+    ) => void
+
+    listener({}, { id: 'pty-contract', data: 'raw', sidecarOnly: true })
+
+    expect(callback).toHaveBeenCalledWith({
+      id: 'pty-contract',
+      data: 'raw',
+      sidecarOnly: true
+    })
+  })
 })