#$etag

#Import

1import { $etag } from "alepha/server/etag";

#Overview

Middleware that enables ETag-based response caching per-route.

Sets per-request etag options in the ALS context. The global ServerEtagProvider hooks read these to generate ETags, handle 304s, and optionally store responses.

When store is enabled, the middleware also checks the cache before calling the handler, short-circuiting on cache hits.

Route middleware — works inside $action, $page, or any pipeline.

 1class UserController { 2  // ETag only (no response caching) 3  getUser = $action({ 4    use: [$etag()], 5    handler: async ({ params }) => { ... }, 6  }); 7  8  // ETag + response caching (store) 9  getProfile = $action({10    use: [$etag(true)],11    handler: async ({ params }) => { ... },12  });13 14  // Fine-grained control15  getStats = $action({16    use: [$etag({ store: { ttl: [5, "minutes"] }, control: { public: true, maxAge: 300 } })],17    handler: async ({ params }) => { ... },18  });19}

Stored responses are namespaced by caller identity (the authorization and cookie headers), so an authenticated route does not serve one user's body to another. Anonymous callers share a single entry.

#Options