Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/mthines/agent-skills/e2e-testingnpx skills add mthines/agent-skills --skill e2e-testinggit clone --depth 1 https://github.com/mthines/agent-skillsWrote 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.
[](https://agentmods.dev/skills/mthines/agent-skills/e2e-testing)<a href="https://agentmods.dev/skills/mthines/agent-skills/e2e-testing"><img src="https://agentmods.dev/badge/skills/mthines/agent-skills/e2e-testing.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00153 | $0.02433 |
| Opus 5 | $0.00077 | $0.01216 |
| Sonnet 5 | $0.00031 | $0.00487 |
| Haiku 4.5 | $0.00015 | $0.00243 |
Grade A, and why
e2e-testing 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 246 lines — stays where its author put it; the contents beside it link to each section on GitHub.
E2E Testing
Drive end-to-end tests through Playwright's MCP-backed Test Agents — Planner, Generator, Healer — released in Playwright 1.56 (Oct 2025). The user writes (or approves) a Markdown feature spec; agents generate the test, run it against a real browser via the accessibility tree, and self-heal when locators drift.
This
SKILL.mdis a thin index. Decision rules live inrules/*.mdand load on demand. Worked references (agent reference, MCP tool catalog, pyramid math) live inreferences/*.md. Literal boilerplate the skill emits lives intemplates/*.md. Do not preload everything — load only what the current phase asks for.
When to use
Reach for this skill when any of the following is true:
- A feature has user-facing flow that integration tests cannot fully cover.
- A bug repros only through real navigation (multi-page, auth, real network).
- A flake needs a Healer pass instead of a manual locator hunt.
- The repo has no
@playwright/mcpwiring yet and needs Phase 0 setup.
Do not reach for this skill when:
- A unit or component test would catch the same bug — defer to
tddand the layer rule inrules/layer-decision.md. - The change is a pure refactor with no behavioural surface.
- You are adding test infrastructure unrelated to a real flow.
Phase 0 — Preflight (mandatory gate)
Before any agent loop, verify the repo is wired for Playwright Test Agents. Halt and ask the user before installing anything.
Run these checks (read-only):
# 1. Playwright + MCP server installed?
jq '.devDependencies | keys[]' package.json | grep -E '@playwright/(test|mcp)'
# 2. Test-agent artefacts present?
ls specs/ tests/seed.spec.ts playwright.config.ts 2>/dev/null
Decision table:
| State | Action |
|---|---|
| Both deps present + artefacts exist | Proceed to Phase 1. |
| Deps missing | Halt. Print install plan, ask permission before running. |
| Deps present, artefacts missing | Halt. Print npx playwright init-agents --loop=claude, ask first. |
Playwright present but version < 1.56 |
Halt. Test Agents require 1.56+. Ask permission to upgrade. |
What ships with it
12 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- references/mcp-tool-catalog.md 5.8 KB
- references/playwright-agents.md 3.7 KB
- references/pyramid-2026.md 2.7 KB
- rules/anti-patterns.md 3.7 KB
- rules/layer-decision.md 3.5 KB
- rules/locator-strategy.md 3.8 KB
- rules/spec-first-flow.md 5.0 KB
- rules/token-budget.md 4.5 KB
- templates/install-plan.md 1.3 KB
- templates/playwright.config.ts 1.1 KB runs code
- templates/seed.spec.ts 852 B runs code
- templates/spec.md 1.1 KB
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.
- 4d ago First seen · 246 lines · 153 tokens per session scan A e2df232e9f4a
e2e-testing is a skill published in the GitHub repository mthines/agent-skills (12 stars, last pushed today), licensed MIT. It adds 153 tokens to every session and 2,433 once invoked, about $0.0008 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 2026-08-31.
Other skills, from other repositories
ego-browser
Skill "ego-browser" from citrolabs/ego-lite, covering ego-browser, quick start, common helpers, task spaces and control handoff.
eval-graphics
Turn an eval study's numbers into on-brand, publish-ready figures using the Newsjack chart room (the eval design system), then validate them with Playwright. For producing the charts in a published eval/data study.
custom-icons
Create or refine custom icon assets as native or traced SVGs and transparent PNG/WebP files. Use when the user asks for a bespoke icon or cohesive icon set, wants an image traced into a clean vector, or needs a detailed or 3D icon with transparency.
design-exploration
Generates multiple distinct design variants of a component or page, each with a completely different visual direction, then implements the chosen one. Use when the user asks to redesign, restyle, explore design options, create multiple visual directions, or compare design approaches for any UI element -- components…
web-design
Design and implement high-quality web interfaces by synthesizing proven design philosophies from Dieter Rams, Brad Frost (Atomic Design), Google Material Design, and modern web best practices. Triggered when the user asks to design a web page, UI component, design system, layout, or when asked to review/improve…
life-design
Walk you through the Stanford Designing Your Life method and write your Personal Life Design Blueprint — three Odyssey plans and the prototypes to test them.