---
name: "hsts-preload-header-hardening"
description: "Force HTTPS connections and eliminate SSL stripping attacks with HSTS Preload."
metadata:
  author: "Chromium HSTS"
  version: "1.0.0"
  runtime_compatibility:
    - "codex"
    - "claude-code"
    - "cursor"
    - "windsurf"
triggers:
  - "configure hsts header"
  - "submit domain to hsts preload"
  - "prevent ssl stripping hsts"
permissions:
  fs_read: true
  fs_write: "workspace"
  shell_exec: false
  net_access: false
---

# HTTP Strict Transport Security (HSTS) Preload

Configures HTTP Strict Transport Security: Strict-Transport-Security: max-age=31536000; includeSubDomains; preload, testing eligibility, and submitting domains to the global HSTS Preload list.

## When to Invoke
Invoke this skill whenever you need to:
- configure hsts header
- submit domain to hsts preload
- prevent ssl stripping hsts

## Execution SOP & Rules
1. Set header: Strict-Transport-Security: max-age=31536000; includeSubDomains; preload.
2. Ensure the initial HTTP connection immediately redirects to HTTPS with a 301 response.
3. Verify all subdomains possess valid, unexpired SSL/TLS certificates.
4. Submit the validated root domain to the Chromium HSTS preload list for permanent browser pinning.

## Verification Checklist
- Run local linting, syntax validation, and type-checks before reporting completion.
- Ensure all created or modified files adhere to workspace boundaries and avoid uncommitted secrets.
- Verify tests or build commands exit cleanly with return code 0.