Does contextBridge.exposeInMainWorld survive same-process renderer navigation?

Direct Answer

Same-document navigations (history.pushState/replaceState): Yes, the exposed API survives. The JavaScript execution context remains intact, so window.exposedApi stays available.

Cross-origin same-process navigations: No, the binding is removed. Electron tears down the isolated context for security, stripping all contextBridge exports from window.

Full document reloads (e.g., window.location.href change): No, the binding is lost. The renderer context is destroyed; the preload script must re-run to re-establish the bridge.

Why the Distinction Matters

Electron's contextBridge ties the exposed object to the document's isolated world, not to the renderer process itself. When the document changes—whether by navigation or reload—the isolated world is recreated. Only same-document history manipulations preserve the existing world.

Behavior by Navigation Type

Navigation Type	Process Reused?	Isolated World Preserved?	contextBridge Binding
history.pushState() / replaceState()	Yes	Yes	Survives
window.location.href = '/same-origin'	Yes (usually)	No	Lost — preload re-executes
Cross-origin (localhost → example.com)	Yes (site-per-process off)	No	Lost — security teardown
location.reload()	Yes	No	Lost — preload re-executes

Verification Steps

1. In your preload script, expose a test API:

   contextBridge.exposeInMainWorld('testBridge', { ping: () => 'pong' });

2. Load the page and confirm window.testBridge.ping() === 'pong'.
3. Call history.pushState({}, '', '/new-path') and re-check — it should still work.
4. Navigate via window.location.href = '/other-page' (same origin) — the API will be undefined until the preload runs again.
5. Navigate cross-origin — the API disappears immediately.

Practical Recommendation

Treat contextBridge bindings as per-document. If your app uses SPA routing (pushState), the bridge persists automatically. For any multi-page flow or cross-origin transition, re-initialize the bridge in the preload script — it runs on every new document load.

One Diagnostic Detail That Changes the Recommendation

Are you using webPreferences.sandbox: true or nodeIntegrationInWorker? These flags can alter process isolation boundaries and may cause the renderer to be recycled differently across navigations. If either is enabled, verify the exact process ID (process.pid in the renderer) before and after navigation to confirm whether the same process truly handles the new document.