mastra: Skill for Claude Code

.claude/skills/e2e-tests-studio/SKILL.md

e2e-tests-studio is a skill for Claude Code from mastra-ai/mastra. It costs 67 tokens per session (3,841 once invoked), scanned A, original, no licence file.

A testing guide that creates Playwright end-to-end tests for changes in the playground UI packages. End-to-end tests check a feature through the product as a user would use it.

In plain words
What is it for?
Use it when creating, changing, or refactoring React components, UI, or features in packages/playground-ui or packages/playground.
Why use it?
It helps catch broken studio behavior instead of checking only whether individual screens look correct.

Skill for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter.

This is mastra-ai/mastra's own configuration. It tells Claude Code how to work on mastra itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything mastra configures →

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is import { resetStorage } from '../__utils__/reset-storage';.

Reuse

Borrowing it

Nothing to install: this file belongs to mastra-ai/mastra. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/mastra-ai/mastra/main/.claude/skills/e2e-tests-studio/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/mastra-ai/mastra

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for e2e-tests-studio

README.md
[![agentmods](https://agentmods.dev/badge/skills/mastra-ai/mastra/e2e-tests-studio/github.svg)](https://agentmods.dev/skills/mastra-ai/mastra/e2e-tests-studio)
Your own site
<a href="https://agentmods.dev/skills/mastra-ai/mastra/e2e-tests-studio"><img src="https://agentmods.dev/badge/skills/mastra-ai/mastra/e2e-tests-studio/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for e2e-tests-studio

Your own site · 80×15
<a href="https://agentmods.dev/skills/mastra-ai/mastra/e2e-tests-studio"><img src="https://agentmods.dev/badge/skills/mastra-ai/mastra/e2e-tests-studio.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 67 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,841 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Socket pass 18 Mar 2026
  • Snyk pass 15 Feb 2026
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 2 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Excessive Agency · line 8
    Skill selects an external model or provider that may use a different account or billing plan than the operator expects. Undisclosed model switches can cause unexpected cost or quota consumption.
    Fix: Remove the model/provider override or disclose it prominently and require explicit operator approval before invoking an external coding CLI or billed model.
  • medium MCP Rug Pull · line 84
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
How audits are shown
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00067 $0.03841
Opus 5 $0.00034 $0.01920
Sonnet 5 $0.00013 $0.00768
Haiku 4.5 $0.00007 $0.00384

Measured 11d ago against content hash 02a0f7222f3e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

e2e-tests-studio scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/e2e-tests-studio/SKILL.md · 459 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 11d ago First seen · 459 lines · 67 tokens per session scan A 02a0f7222f3e

Subscribe to this mod's changes

e2e-tests-studio is a skill published in the GitHub repository mastra-ai/mastra (27,896 stars, last pushed today), with no licence file. It adds 67 tokens to every session and 3,841 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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