Laravel ↔ Vue/React: Inertia.js Redirect and Status‑Code Interoperability

Goal

Determine how Inertia.js should behave when a server framework (e.g., Laravel) returns a 302 status code together with a valid Inertia JSON payload that includes a redirect key, and how the various client adapters (Vue, React, Svelte) interpret that response.

Constraints & Uncertainty

• The official documentation states a 200 status is required for a valid Inertia response, yet does not forbid 3xx responses with an Inertia body.
• The redirect key is not formally part of the public contract, and the default shouldRedirect callback implementation is undocumented.
• Adapter implementations differ: some automatically follow the redirect, others render the component and ignore the navigation instruction.

Specific questions:

1. Should a 302 response with an Inertia payload be treated as a client‑side redirect by default, or must the client explicitly handle the redirect key?
2. Is the presence of the redirect key guaranteed to remain stable across future Inertia releases?
3. What is the recommended pattern for handling 4xx/5xx responses that still contain a valid Inertia payload?