How do I install the New Tab skill?

Run npx skillmds@latest add thedaviddias/new-tab in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is New Tab safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with New Tab?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is New Tab free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published New Tab?

thedaviddias (@thedaviddias) published this skill. Their other Agent Skills are listed on their SkillMD profile.

New Tab by thedaviddias — Agent Skill

Name: New Tab
Author: thedaviddias

File contents

External Link Security

A malicious site opened via target='_blank' can use window.opener.location to silently redirect your original tab to a phishing page — the user switches back and sees a fake login screen on what appears to be your domain.

Quick Reference

Always add rel="noopener noreferrer" to any <a target="_blank"> link
noopener prevents the new tab from accessing window.opener and redirecting your page
noreferrer additionally suppresses the Referer header sent to the destination site
Modern browsers (Chrome 88+, Firefox 79+) implicitly add noopener for cross-origin _blank links, but explicit markup is required for older browsers and same-origin links
ESLint rule jsx-a11y/anchor-is-valid and eslint-plugin-security can enforce this automatically

Check

Find all anchor elements with target='_blank' in the HTML and JSX source. Verify each one includes rel='noopener noreferrer' (or at minimum rel='noopener'). Flag any external links opening in a new tab that are missing this attribute.

Fix

Add rel='noopener noreferrer' to all elements. In React/JSX this is rel="noopener noreferrer". Configure an ESLint rule to prevent this from recurring.

Explain

Explain the reverse tabnapping attack enabled by window.opener, how rel='noopener' and rel='noreferrer' prevent it, and the difference between the two values.

Code Review

Review server config, headers, forms, and integration points related to External Link Security. 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/en/rules/security/new-tab

---name: new-tabdescription: Use when reviewing HTML or JSX for anchor elements with target='_blank' to verify rel='noopener noreferrer' is present.---# External Link SecurityA malicious site opened via target='_blank' can use window.opener.location to silently redirect your original tab to a phishing page — the user switches back and sees a fake login screen on what appears to be your domain.## Quick Reference- Always add `rel="noopener noreferrer"` to any `<a target="_blank">` link- `noopener` prevents the new tab from accessing `window.opener` and redirecting your page- `noreferrer` additionally suppresses the `Referer` header sent to the destination site- Modern browsers (Chrome 88+, Firefox 79+) implicitly add `noopener` for cross-origin `_blank` links, but explicit markup is required for older browsers and same-origin links- ESLint rule `jsx-a11y/anchor-is-valid` and `eslint-plugin-security` can enforce this automatically## CheckFind all anchor elements with target='_blank' in the HTML and JSX source. Verify each one includes rel='noopener noreferrer' (or at minimum rel='noopener'). Flag any external links opening in a new tab that are missing this attribute.## FixAdd rel='noopener noreferrer' to all <a target='_blank'> elements. In React/JSX this is rel="noopener noreferrer". Configure an ESLint rule to prevent this from recurring.## ExplainExplain the reverse tabnapping attack enabled by window.opener, how rel='noopener' and rel='noreferrer' prevent it, and the difference between the two values.## Code ReviewReview server config, headers, forms, and integration points related to External Link Security. 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/en/rules/security/new-tab

Frequently asked questions

New Tab