[detaro]

> The article states that to update SWR `cache-control` headers you need to use the `headers` property of `vercel.json`[3]. This is for changing the headers of static assets, not Vercel Function responses (Serverless or Edge Functions).

Then why does [3] say "This example configures custom response headers for static files, Serverless Functions, and a wildcard that matches all routes.", if it isn't for changing the headers on Serverless Functions? (EDIT: my bet would've been that its adding the headers outgoing from the CDN, not from the function, but your claim above contradicts that too)

[leerob]

That should be more clear! I'll update, thank you. Basically, you should always use the framework or "product native" way of adding caching headers. For Serverless Functions (that use Node.js), that's the `response.setHeader()` API[1]. For Edge Functions (that use Web APIs), that's using the Web Response API and passing a headers object[2].

Most of the time folks using Vercel aren't actually using these Functions manually, but instead having framework-defined infrastructure[3] that generates the functions based on their framework-native code (e.g. `getServerSideProps` in Next.js)

[1]: https://vercel.com/docs/concepts/functions/serverless-functi...

[2]: https://vercel.com/docs/concepts/functions/edge-functions/ed...

[3]: https://vercel.com/blog/framework-defined-infrastructure

[transitivebs]

Hey Lee, Travis here.

One piece of meta feedback for Vercel reading through all this is that whenever you have multiple ways of accomplishing something (like setting headers in vercel.json vs in the handlers themselves), it's bound to cause confusion.

Love Vercel :)