Inertia Protocol Support

Guren ships its own Inertia server adapter inside @guren/core, written against the Inertia protocol as @inertiajs/react 3 speaks it. This page is the coverage table: which parts of the protocol the adapter implements, which it leaves out, and where each part is documented. If you arrive from the Laravel, Rails or AdonisJS adapter, read this page first and the Frontend guide second.

The Shape of an Inertia App in Guren

A controller renders a page by name and hands it props. Page names come from codegen, so a typo in the component path or a missing prop fails at compile time rather than at runtime:

import { Controller } from '@guren/core'
import { pages } from '@/.guren/pages.gen'

export class UserController extends Controller {
  async index() {
    return this.inertia(pages.users.Index, {
      users: () => User.all(),
    })
  }
}

The page component lives under resources/js/pages/users/Index.tsx and declares its Props. bunx guren codegen extracts that interface and types the controller call against it. The Frontend guide covers the project layout, forms and the type flow.

Protocol Coverage

Protocol feature	Status	In Guren
HTML document with the embedded page object	Supported	The page object is serialized with < escaped, so prop data cannot close the <script> element.
Inertia JSON responses (X-Inertia, Vary)	Supported	Vary lists Accept, X-Inertia and the three partial-reload headers.
Asset versioning (version, 409 with X-Inertia-Location on a GET mismatch)	Supported	The version comes from the version option or GUREN_INERTIA_VERSION, which the asset bootstrap sets from the Vite manifest. The 409 is decided before any prop resolves, so a stale client never runs a lazy query. It does not echo X-Inertia-Version.
Partial reloads (X-Inertia-Partial-Component, -Data, -Except)	Supported	Top-level keys only: author.name in the header selects author. See Partial Reloads.
Lazy props (a function evaluated only when sent)	Supported	Pass () => value. The page's Props still declares the resolved type.
Always props	Supported	always(value). errors is shared this way.
Deferred props with groups (deferredProps)	Supported	defer(() => value, group). See Deferred Props.
Rescued deferred props (rescuedProps)	Not supported	A deferred callback that throws fails the follow-up request.
Optional props	Not supported	Use defer() where the data can arrive after the first render.
Merge, prepend and deep merge props (mergeProps, prependProps, deepMergeProps, matchPropsOn)	Not supported	A partial reload replaces the prop.
Once props (onceProps, X-Inertia-Except-Once-Props)	Not supported
Infinite scroll (scrollProps)	Not supported	Builds on merge props.
Resetting props (X-Inertia-Reset)	Not supported	Nothing merges, so there is nothing to reset.
History encryption (encryptHistory, clearHistory)	Not supported
Validation errors in the errors prop	Supported	A ValidationException on an Inertia request flashes the errors and redirects back with 303; the next render carries one message per field. Works without a session through a cookie. See Form Validation Errors.
Error bags (X-Inertia-Error-Bag)	Not supported	Errors are one flat object per page.
Redirects (303 after a non-GET request)	Supported	this.redirect() answers a non-GET request with 303.
External redirects (409 with X-Inertia-Location)	No helper	Return a Response with status 409 and the header yourself.
Fragment redirects (X-Inertia-Redirect, preserveFragment)	Not supported
Shared data	Supported	shareInertiaProps() resolves per request and passes through the partial-reload filter. The sharedProps page key is not emitted.
Flash data in the page object (flash)	Not supported	Share a flash value as an always() prop instead.
CSRF (XSRF-TOKEN cookie, X-XSRF-TOKEN header)	Supported	See Inertia.js Integration.
Server-side rendering	Supported, in process	renderInertiaServer() runs inside the app rather than as a separate Node server, so the /render, /health and /shutdown contract does not apply. A failed render logs and falls back to client rendering. See Server-Side Rendering.
Prefetching (Purpose: prefetch)	Needs nothing from the server	The client feature works as is.
Precognition	Not supported

Client-side features that need no server support, such as <WhenVisible>, usePrefetch and the <Form> component, work as @inertiajs/react documents them.

Testing

TestApp asserts on the page object directly:

await app.get('/users').assertInertia('users/Index', { users: [] })

The controller mock in @guren/testing resolves lazy, always and deferred props through the same rule the runtime uses, so a controller test sees the prop set a browser would receive. See the Testing guide.

Beyond the Protocol

These are the parts a reader coming from another adapter will not find there:

• Page ids and Props are generated, so this.inertia() is checked against the component's declared props, and ControllerInertiaProps reads the resolved type back for the page.
• createTypedLink() and createTypedForm() from @guren/inertia-client check route names and params at compile time.
• bunx guren check warns when a controller passes defer() for a prop the page declares as required.
• Prototype mode serves a page from a fixture before any controller exists. See Prototype-First.

Client Frameworks

The scaffold and @guren/inertia-client target React. The server adapter does not depend on which Inertia client sends the request, but Guren ships no Vue or Svelte scaffold, SSR entry or typed components.

Next Steps

• Frontend: page components, forms, partial reloads, deferred props and SSR.
• Validation: how validation errors reach an Inertia form.
• Testing: assertInertia() and the controller mock.