# Rejected requests

> Why a local server or workspace request returns 403 Forbidden and how loopback, origin, and symlink checks work.

Source: https://hyperclaylocal.com/docs/rejected/

Every folder server in Hyperclay Local enforces origin-wide loopback, `Origin`, Fetch Metadata, and symlink checks. These rules apply across the entire origin, not per route, and are the usual reason a request that looks valid returns `403 Forbidden`.

## Loopback Host header

The `Host` header must name a loopback address: `localhost`, any `127.x.x.x` address, or `::1` in any valid IPv6 spelling. Any other `Host` value returns `403` with `Invalid Host header`.

Checking the `Host` header stops DNS rebinding attacks, which binding the socket to `127.0.0.1` alone does not prevent.

## Cross-origin write protection

On `POST`, `PUT`, `PATCH`, and `DELETE` requests:

- `Sec-Fetch-Site: cross-site` is refused.
- `Origin: null` is refused.
- Any other `Origin` header must be a loopback origin on any port (`http://localhost:<port>`, `http://127.x.x.x:<port>`, or `http://[::1]:<port>`).
- A request with no `Origin` header at all is allowed, which is why `curl`, local shell scripts, helper programs, and the sync engine work.

Refused write requests return `403` with a JSON error body:

```json
{"msg":"Cross-origin requests are not allowed.","msgType":"error"}
```

## Single-user cookies on local ports

Every request to a served folder sets `isAdminOfCurrentResource=true` and `isLoggedIn=true` cookies. Each local folder server is single-user by design: whoever can reach the folder's port (`4321` for your personal folder, or a team folder's local port; see [Folders and ports](https://hyperclaylocal.com/docs/folders-and-ports/)) owns every file in that folder. There is no user authentication on local folder routes.

The [workspace window](https://hyperclaylocal.com/docs/guide/workspace/) shell server applies an additional per-launch token (`X-Workspace-Token`) alongside `Host`, `Origin`, and Fetch Metadata checks on its internal API routes. When you open `http://localhost:<port>/` in a browser, the server redirects through `/enter?ticket=...` using a one-time ticket that expires after 60 seconds; an unknown or expired ticket returns `403 Forbidden`, while a valid ticket sets an `HttpOnly`, `SameSite=Lax` cookie named `hyperclay-workspace-<port>` for 24 hours.

## Symlinks

Symlinks pointing outside the served folder are consented at open time only:

- A symlink created while the server is running is refused on both reads and writes.
- `/_/uploads/` serves only files inside the real `uploads/` folder, so a symlink pointing outside `uploads/` reaches nothing (see [Metadata and uploads](https://hyperclaylocal.com/docs/metadata-and-uploads/)).
- `@file` context in [AI editing](https://hyperclaylocal.com/docs/guide/ai-editing/) follows symlinks only when the target stays inside the served folder, and refuses hidden files and folders both by name and after resolving symlinks.