Vercel moves FastAPI frontends and static files to its CDN

Vercel now lifts FastAPI frontends and static file mounts to its CDN at build time, replacing per-request serving from the function, as of September 10. That means fewer function invocations for content that doesn't change between requests, and more headroom for requests that do need Python running.

Apps that declare a frontend with app.frontend() or mount files through StaticFiles get pushed to the edge once, at deploy. They no longer re-run through Python on every hit.

Route precedence still holds. A route declared ahead of a StaticFiles mount wins over a CDN-served file at the same path, per Vercel's FastAPI-and-static-files changelog.

The catch is anything gated at request time. Frontends behind FastAPI dependencies stay on the function. So do static files behind middleware, since the CDN can't run those checks before deciding what to serve.

Static assets gated by an auth dependency or a middleware flag get no benefit yet. That logic has to move somewhere the CDN can see it, or the gated files need to be split from the ungated ones.

Separately, Vercel doubled Sandbox storage to 64 GB per sandbox, including custom images, with no price change mentioned, per Vercel's Sandbox storage changelog. The old 32 GB ceiling was a real wall for agents cloning a large monorepo while keeping a build cache resident at the same time.