Fix SPA mode URL detection for Octane & alternative runtimes (FrankenPHP, Swoole, containers)

[eslam-reda-div]

Fixes an issue where Filament SPA mode fails when running on non PHP-FPM runtimes such as Laravel Octane (FrankenPHP, Swoole) and in containerized or load-balanced environments.

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Issue

SPA mode relies on is_app_url() to determine whether a URL belongs to the application.
The previous implementation depended solely on request()->root(), which is not reliable in:

• Octane runtimes (FrankenPHP / Swoole)
• Reverse proxies and load balancers
• Containers where the public app URL differs from the internal request root

This causes Filament to incorrectly treat internal URLs as external, breaking SPA navigation.

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Change

Update is_app_url() to:

• Prefer config('app.url') as the canonical application URL
• Correctly handle relative URLs
• Retain request()->root() as a safe fallback for backward compatibility

function is_app_url(string $url): bool
{
    if (str($url)->startsWith('/') && ! str($url)->startsWith('//')) {
        return true;
    }

    $appUrl = rtrim((string) config('app.url'), '/');

    return ($appUrl !== '' && str($url)->startsWith($appUrl))
        || rescue(fn () => str($url)->startsWith(request()->root()), false);
}

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Impact

• ✅ Fixes SPA mode on Octane (FrankenPHP, Swoole)
• ✅ Works correctly behind proxies and in containers
• ✅ No breaking changes
• ✅ More predictable behavior across all runtimes

[SerjoA]

can this be merged to v3.3 also?

[SerjoA]

this can be solved in filament 3.3 using trusted hosts and proxies in app middleware