Static assets

assets.directory in the wrangler file serves files before, or instead of, the Worker, with the behaviour of celld’s asset server, which follows Cloudflare’s. A project may have assets and no main.

{
  "name": "static-assets",
  "compatibility_date": "2026-01-01",
  "assets": { "directory": "./public" }
}

This is celld’s static-assets example (conformance/celld-examples/static-assets), copied unchanged and run by the conformance suite on Node and in Chromium.

What the asset server does

• GET and HEAD only; run_worker_first; assets.binding exposes env.ASSETS.
• _redirects first (301, 302, 303, 307, 308 to Location; 200 rewrites; * to :splat), then _headers rules.
• html_handling auto-trailing-slash, with a 307 to the canonical path; not_found_handling (with a Worker, only for navigation requests).
• A strong SHA-256 ETag, If-None-Match → 304, Range → 206 or 416, and Cache-Control: public, max-age=0, must-revalidate by default. A file with an unknown extension gets no Content-Type.

Where CellB follows Cloudflare instead of celld

How it is checked

celld’s static-assets example and CellB’s assets-api, assets-drop and assets-force projects, on Node and in Chromium.