.tip

Jun 8, 2026 · one of the small things

Vary tells the cache which headers change the response

A response that differs by Accept-Language or by a custom header will be served to the wrong user by any cache that does not know that.

Vary: Accept-Encoding, Accept-Language

Never Vary: Cookie on a cached response. It makes the cache useless. If a response depends on the cookie it should be no-store or private.

httpcaching

~/tips/today — 2026-09-04

~cat tips/today

Session cookies: HttpOnly, Secure, SameSite=Lax

securityhttp

Three attributes, each closing a class of attack. HttpOnly keeps scripts from reading it. Secure keeps it off plain HTTP. SameSite=Lax stops it being sent on cross-site POSTs, which is most CSRF.

Set-Cookie: session=...; HttpOnly; Secure; SameSite=Lax; Path=/; Max-Age=1209600

Strict breaks arriving from an external link while logged in. Lax is the default worth keeping.

↵ open y yesterday l ls /tips

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