Unclear documentation for Vercel adapter ISR bypassToken (__prerender_bypass)

[Leftium]

Describe the bug

It is not clear how the Vercel ISR cache can be bypassed:

A random token that can be provided in the URL to bypass the cached version of the asset, by requesting the asset with a __prerender_bypass= cookie.

• Can a URL param be added? (Which would result in the Vercel adapter injecting the __prerender_bypass cookie)
• Is GET/HEAD request with header x-prerender-revalidate: <token> a second, alternate method of bypassing the ISR cache?

It seems:

• https://example.com/?__prerender_bypass=<token> does not work (may be convenient if it did work)
• The __prerender_bypass=<token> cookie does work
• Did not test x-prerender-revalidate (assuming it probably works)

Reproduction

• https://svelte.dev/docs/kit/adapter-vercel#Incremental-Static-Regeneration-bypassToken
• https://github.com/sveltejs/kit/blob/f4ce1856ad9ea446c424bd818b25ae89e34a0692/documentation/docs/25-build-and-deploy/90-adapter-vercel.md#bypasstoken

Severity

annoyance

[droplab]

A GET request with header x-prerender-revalidate: <token> does not work in numerous tests I've attempted.