HTTP 510 Not Extended

What is HTTP 510 Not Extended?

The 510 (Not Extended) status code indicates that the policy for accessing the resource has not been met in the request. This is related to the HTTP Extension Framework, which allows for additional extensions to be negotiated between client and server.

Common Use Cases

• HTTP extension policy negotiation
• Custom protocol extension requirements

// Practical alternative - requiring a custom header
if (! $request->header('X-API-Version')) {
    return response()->json([
        'error' => 'API version header required',
    ], 510);
}