Cookie Sync (Android)

Bridges Android's WebView CookieManager with nitro-fetch's Cronet client and the cold-start token-refresh path. Useful when your auth flow stores the session cookie in the WebView cookie jar (e.g. SAML, OAuth login pages rendered in a WebView) and you need subsequent native fetches to send it.

When enabled:

• Outbound requests: if the request has no Cookie header, the matching cookies from CookieManager are attached for the request URL.
• Inbound responses: any Set-Cookie headers (including those returned during redirects) are stored back into CookieManager. Persistence is flushed once per request after the final response.

User-set Cookie headers are always respected — sync never overwrites them.

Enable

Cookie sync is opt-in and disabled by default. Enable it once from your Application.onCreate() (or any code path that runs before the first fetch / auto-prefetch):

// android/app/src/main/java/.../MainApplication.kt
import com.margelo.nitro.nitrofetch.NitroCookieSync

class MainApplication : Application(), ReactApplication {
  override fun onCreate() {
    super.onCreate()
    NitroCookieSync.enableCookieSync()
    // ...rest of your onCreate
  }
}

That's it — both the Cronet client (fetch) and the HttpURLConnection token-refresh path will start syncing cookies on the next request.

Notes

• Android only. iOS URLSession already shares cookies with WKWebView via HTTPCookieStorage and needs no opt-in.
• Token-refresh redirects: HttpURLConnection follows redirects internally and only the final response's Set-Cookie headers are visible. If your refresh endpoint sets cookies on a 3xx hop, point it directly at the final URL.