Checking HTTP Security Headers
jeremylongshore/tons-of-skills-marketplace
Audit a target's HTTP security headers — CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, and the Cross-Origin trio (COOP, COEP, CORP).
A skill your agent uses when reviewing HTTP response headers for clickjacking protection on any web application with authenticated user actions.
MITAuto-check passed
Install X Frame Options
$ npx skills add thedaviddias/Front-End-Checklist --skill x-frame-options -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install thedaviddias/Front-End-Checklist x-frame-options --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/x-frame-options .claude/skills/x-frame-options && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "x-frame-options" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/x-frame-options into .claude/skills/x-frame-options/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "x-frame-options", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/x-frame-optionsType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add thedaviddias/Front-End-Checklist --skill x-frame-options -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install thedaviddias/Front-End-Checklist x-frame-options --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/x-frame-options .agents/skills/x-frame-options && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "x-frame-options" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/x-frame-options into .agents/skills/x-frame-options/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "x-frame-options", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add thedaviddias/Front-End-Checklist --skill x-frame-options -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install thedaviddias/Front-End-Checklist x-frame-options --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/x-frame-options .cursor/skills/x-frame-options && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "x-frame-options" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/x-frame-options into .cursor/skills/x-frame-options/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "x-frame-options", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/thedaviddias/Front-End-Checklist.git --path skills/x-frame-options--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add thedaviddias/Front-End-Checklist --skill x-frame-options -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install thedaviddias/Front-End-Checklist x-frame-options --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/x-frame-options .gemini/skills/x-frame-options && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "x-frame-options" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/x-frame-options into .gemini/skills/x-frame-options/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "x-frame-options", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install thedaviddias/Front-End-Checklist x-frame-optionsInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add thedaviddias/Front-End-Checklist --skill x-frame-options -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/x-frame-options .github/skills/x-frame-options && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "x-frame-options" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/x-frame-options into .github/skills/x-frame-options/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "x-frame-options", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add thedaviddias/Front-End-Checklist --skill x-frame-options -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install thedaviddias/Front-End-Checklist x-frame-options --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/x-frame-options .opencode/skills/x-frame-options && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "x-frame-options" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/x-frame-options into .opencode/skills/x-frame-options/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "x-frame-options", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
x-frame-options- GitHub stars
- 74k
- Token cost
- ~547 tokens
- SKILL.md length
- 235 words
- Files
- 2 (incl. references)
- Skills in repo
- 390
- Repo updated
- First seen
- Licence
- MIT
At a glance
A skill your agent uses when reviewing HTTP response headers for clickjacking protection on any web application with authenticated user actions.
- Reviewing HTTP response headers for clickjacking protection on any web application with authenticated user actions
- SKILL.md covers Quick Reference, Check, Fix and Explain, plus 1 more section
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
X Frame Options is an agent skill from thedaviddias/Front-End-Checklist. Use when reviewing HTTP response headers for clickjacking protection on any web application with authenticated user actions.
Its SKILL.md is about 550 tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including reference files (for example `references/rule.md`).
The repository describes itself as: 🗂 The essential checklist for modern web development, for humans and AI agents. The licence is MIT.
When your agent uses it
- Reviewing HTTP response headers for clickjacking protection on any web application with authenticated user actions
Example prompts
- “/x-frame-options”
What it can do on your machine
Read from SKILL.md and the folder at commit e8d14d0. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
Links to these hosts (documentation or services it may open):
frontendchecklist.io
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
X Frame Options loads about 547 tokens when it runs, and up to ~1.8k if it reads all its reference files. Until then it costs about 35 tokens; SKILL.md has 235 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from thedaviddias/Front-End-Checklist at commit e8d14d0, republished under its MIT licence (© thedaviddias). 235 words, ~547 tokens.
Download SKILL.mdSave it as
.claude/skills/x-frame-options/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.- name
- x-frame-options
- description
- Use when reviewing HTTP response headers for clickjacking protection on any web application with authenticated user actions.
- metadata.category
- security
- metadata.priority
- high
- metadata.difficulty
- beginner
- metadata.estimatedTime
- 5
- metadata.source
- frontendchecklist.io
- metadata.url
- https://frontendchecklist.io/rules/security/x-frame-options
Set an X-Frame-Options header
Without framing protection, an attacker can embed your banking login page in a transparent iframe on a malicious site and trick users into clicking buttons they cannot see — transferring money, changing settings, or leaking credentials.
Quick Reference
- Use
X-Frame-Options: DENYto prevent all framing, orSAMEORIGINto allow framing only from your own domain ALLOWFROMis obsolete and unsupported in modern browsers — use CSPframe-ancestorsinstead- The modern equivalent is
Content-Security-Policy: frame-ancestors 'none'— prefer CSP for new sites - Both headers can coexist: X-Frame-Options for older browsers, frame-ancestors for modern ones
- Clickjacking attacks trick users into clicking invisible iframe buttons — DENY eliminates this entirely
Check
Check whether the server sends an X-Frame-Options header (DENY or SAMEORIGIN) or a Content-Security-Policy header with frame-ancestors directive to prevent clickjacking.
Fix
Add X-Frame-Options: DENY to all responses if the site does not need to be embedded anywhere. If legitimate framing is needed on the same origin, use SAMEORIGIN. For fine-grained control, use CSP frame-ancestors instead.
Explain
Explain what a clickjacking attack is, how X-Frame-Options and CSP frame-ancestors prevent it, and the difference between DENY and SAMEORIGIN values.
Code Review
Review server config, headers, forms, and integration points related to Set an X-Frame-Options header. Flag exact responses, cookies, or browser behaviors that violate the rule, and verify them against the effective production-like response.
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/rules/security/x-frame-options
© thedaviddias, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 1 other file (references) in skills/x-frame-options of thedaviddias/Front-End-Checklist.
- SKILL.md
- references/rule.md
Open the folder on GitHubat commit e8d14d0
Compare with similar skills
X Frame Options next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| X Frame Options this skillthedaviddias/Front-End-Checklist | 74k | — | ~547 | Automated safety check: Pass | MIT | |
| Checking HTTP Security Headersjeremylongshore/tons-of-skills-marketplace | 2.8k | — | ~1.6k | Automated safety check: Pass | MIT | |
| HTTP MCP Headersgithub/gh-aw | 5.4k | — | ~1.2k | Automated safety check: Pass | MIT | |
| HTTP Response HandlingHKUDS/OpenSpace | 7.8k | — | ~1k | Automated safety check: Pass | MIT | |
| Optionsasgeirtj/system_prompts_leaks | 69k | — | ~918 | Automated safety check: Pass | CC0-1.0 | |
| HTTP Header Security Auditjeremylongshore/tons-of-skills-marketplace | 2.8k | — | ~596 | Automated safety check: Pass | MIT |
Similar skills
- Official
HTTP MCP Headers
github/gh-aw
Implement secret-safe HTTP headers for MCP transport in gh-aw.
HTTP Response Handling
HKUDS/OpenSpace
Handle websites requiring JavaScript by using curl with browser headers and validating file types.
Options
asgeirtj/system_prompts_leaks
Present multiple design options as a vertical stack of anchored turns
HTTP Header Security Audit
jeremylongshore/tons-of-skills-marketplace
Execute http header security audit operations. An agent skill from jeremylongshore/tons-of-skills-marketplace.
Responsive Design
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Implement modern responsive layouts using container queries, fluid typography, CSS Grid, and mobile-first breakpoint strategies.
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Questions about X Frame Options
What does X Frame Options do?
A skill your agent uses when reviewing HTTP response headers for clickjacking protection on any web application with authenticated user actions. X Frame Options is an agent skill from thedaviddias/Front-End-Checklist. Use when reviewing HTTP response headers for clickjacking protection on any web application with authenticated user actions.
When should I use X Frame Options?
X Frame Options fits situations like: reviewing HTTP response headers for clickjacking protection on any web application with authenticated user actions.
How do I install X Frame Options in Claude Code?
Run `npx skills add thedaviddias/Front-End-Checklist --skill x-frame-options -a claude-code`. Or copy the skill folder (skills/x-frame-options in thedaviddias/Front-End-Checklist) into .claude/skills/x-frame-options in your project. Claude Code loads it when a task matches its description.
How do I install X Frame Options in Codex?
Run `npx skills add thedaviddias/Front-End-Checklist --skill x-frame-options -a codex`. Or copy the skill folder (skills/x-frame-options in thedaviddias/Front-End-Checklist) into .agents/skills/x-frame-options in your project. Codex loads it when a task matches its description.
Can I use X Frame Options in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add thedaviddias/Front-End-Checklist --skill x-frame-options -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/x-frame-options, .gemini/skills/x-frame-options, .github/skills/x-frame-options and .opencode/skills/x-frame-options in your project.
What does X Frame Options need to run?
SKILL.md names no scripts, command-line tools or credentials: X Frame Options is instructions for the agent only.
Does X Frame Options access the network?
SKILL.md names 1 domain. As links in the text: frontendchecklist.io. This is read from the text; nothing was executed.
Is X Frame Options safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does X Frame Options use?
X Frame Options is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does X Frame Options use?
About 547 tokens (SKILL.md is roughly 2.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 1.3k tokens, read only when the agent opens those files.
What are the alternatives to X Frame Options?
Skills that share tags, products or a category with X Frame Options: Checking HTTP Security Headers (jeremylongshore/tons-of-skills-marketplace, 2.8k stars), HTTP MCP Headers (github/gh-aw, 5.4k stars), HTTP Response Handling (HKUDS/OpenSpace, 7.8k stars) and Options (asgeirtj/system_prompts_leaks, 69k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains X Frame Options?
thedaviddias (a GitHub user) maintains it in thedaviddias/Front-End-Checklist, which has 74,421 GitHub stars. The repository holds 390 skills in this directory. The repository was last updated on October 6, 2026.
Source: thedaviddias/Front-End-Checklist on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.