Security

HTTP Strict Transport Security sounds simple: send one response header and browsers stop using plain HTTP for your domain. With AWS API Gateway, it’s a little messier. The short version: API Gateway can return Strict-Transport-Security, but whether HSTS actually helps depends on how clients reach your API, whether you use a custom domain, and whether any HTTP endpoint still exists in front of it. If you only remember one thing, remember this: HSTS protects browser traffic for hostnames, not APIs in the abstract. If your API is consumed by server-to-server clients, mobile apps, or SDKs, HSTS is mostly irrelevant. If your API is called from browser-based apps on a custom domain, then it absolutely matters. ...

HSTS in Ktor is simple once you know where to put it, and easy to get wrong if you treat it like just another header. Strict-Transport-Security tells browsers: “for this domain, use HTTPS only for a while.” After a browser sees it over a valid HTTPS response, future HTTP requests get upgraded to HTTPS before they ever leave the browser. That blocks protocol downgrade attacks and strips out a whole class of sloppy redirect problems. ...

HSTS is one of those headers that’s easy to enable and surprisingly easy to get wrong. If you run a REST API with Express, HSTS tells clients: “Stop trying plain HTTP for this host. Use HTTPS only for a while.” That sounds simple, but the details matter a lot in production, especially behind proxies, load balancers, and CDNs. This guide is the version I wish more API teams used: what to send, when to send it, and what not to do. ...

HSTS is one of those headers that’s dead simple on paper and weirdly easy to mess up in production. If you run a TypeScript app with tRPC, you usually don’t “add HSTS to tRPC” directly. You add it at the HTTP layer that serves your tRPC endpoint: Express, Fastify, Next.js custom server, Nginx, your edge platform, or your CDN. That distinction matters because if you set it in the wrong place, your API might still be exposed over plain HTTP during redirects or on subdomains you forgot existed. ...

HTTP Strict Transport Security is one of those headers you set once, then forget about until you realize your rollout plan was sloppy. If you run a Dart app with Shelf, HSTS is straightforward: send a Strict-Transport-Security response header on HTTPS responses, and don’t break local development while doing it. This guide is the practical version: what to send, when to send it, and copy-paste Shelf middleware you can actually use. ...

HSTS looks simple: send one response header and browsers stop talking to your site over plain HTTP. The catch is that HSTS is one of those headers that can absolutely improve security and absolutely break things if you roll it out carelessly. I’ve seen teams flip on includeSubDomains in production and then spend the afternoon finding forgotten subdomains, old staging boxes, and random vendor callbacks still using HTTP. If you’re running Fastify, you’ve got a few ways to handle HSTS: ...

HSTS is one of those headers that looks trivial until you ship it wrong. For Koa apps, the mechanics are easy: send Strict-Transport-Security over HTTPS. The hard part is rollout, preload, proxies, subdomains, and not bricking a staging or legacy setup by accident. This guide is the version I wish more teams had on hand: what to send, when to send it, and copy-paste Koa examples that won’t surprise you later. ...

A few years ago, I helped clean up a messy HTTPS rollout for a mid-sized SaaS app. On paper, the setup looked fine: valid TLS cert, HTTPS redirect, load balancer in front, and a decent-looking security checklist in the wiki. In production, it was shaky. Users could still hit http:// directly. Some static assets loaded from old subdomains with mismatched certificates. One internal team wanted to turn on HSTS preload immediately because they’d read that “preload means maximum security.” That would have been a great way to lock broken TLS behavior into every browser. ...

HSTS is one of those headers that’s boring right up until the day it saves you from a nasty downgrade or cookie theft issue. If you’re running a Crystal app with Kemal, HSTS is usually easy to add. The hard part is deciding how aggressive to be. Short max-age? Long max-age? Include subdomains? Preload? Those choices have real operational consequences, especially if you run staging environments, legacy subdomains, or mixed infrastructure. ...

If you run a Play app in production and you’re still treating HTTPS as “mostly enabled,” HSTS is one of the easiest ways to stop users from ever hitting your site over plain HTTP again. The idea is simple: tell the browser, “for this domain, only use HTTPS for a while.” After that, even if someone clicks an old http:// link or a network attacker tries SSL stripping, the browser upgrades the request before it leaves the machine. ...