What is create-yaml-tests?

A guide for creating and maintaining Shiplight YAML end-to-end tests. Shiplight is a testing tool, YAML is a human-readable configuration format, and end-to-end tests check a web application through complete user flows.

It helps create new Shiplight projects, add or fix YAML tests, validate them, and maintain existing tests.

It provides a defined process for setting up test projects, authentication, target URLs, test specifications, and repairs.

create-yaml-tests — Skill for Claude Code and Codex by ShiplightAI

Install

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.

Any agent

npx skills add ShiplightAI/agent-skills --skill create-yaml-tests

Clone the repo

git clone --depth 1 https://github.com/ShiplightAI/agent-skills

Made for: Claude Code, Codex.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/shiplightai/agent-skills/create-yaml-tests/github.svg)](https://agentmods.dev/skills/shiplightai/agent-skills/create-yaml-tests)

Your own site

<a href="https://agentmods.dev/skills/shiplightai/agent-skills/create-yaml-tests"><img src="https://agentmods.dev/badge/skills/shiplightai/agent-skills/create-yaml-tests/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/shiplightai/agent-skills/create-yaml-tests"><img src="https://agentmods.dev/badge/skills/shiplightai/agent-skills/create-yaml-tests.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,183 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.

Origin original 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.

Model	Per session	Once invoked
Fable 5.1	$0.00045	$0.01183
Opus 5	$0.00023	$0.00592
Sonnet 5	$0.00009	$0.00237
Haiku 4.5	$0.00005	$0.00118

Measured 9d ago against content hash 6caae528085b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

create-yaml-tests 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 9d 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.

skills/create-yaml-tests/SKILL.md · 119 lines

How it starts

The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Create Shiplight Tests

This is the single entry point for Shiplight E2E test work.

Use this skill when the user wants to:

Create a new local Shiplight test project
Add YAML tests for a web application
Update or fix existing Shiplight YAML tests
Set up or repair target URLs, accounts, or auth setup
Plan what product behavior should be tested

Daily Skill Update Check

Before starting this skill's work, opportunistically refresh Shiplight skills at most once per day:

Check the timestamp file at .shiplight-agent-skills-last-update in the current project.
If the timestamp file is missing, create it with the current timestamp and continue without running npx -y skills@latest update -y. Treat .shiplight-agent-skills-last-update as local cache and do not commit it.
If the timestamp file exists and is older than 24 hours, run npx -y skills@latest update -y, then create/update the timestamp file even if the command fails.
If the update command fails, continue with the currently installed skill and mention the failure briefly.

Test Project Root

Before reading or writing project files, identify the Shiplight test project root. All paths in this skill are relative to that root.

If the root is not clear, ask the user to confirm it before creating or moving files.

Canonical Project Layout

Shiplight test projects use this layout:

specs/context.md       project-level app, risk, data, and target-deployment context
specs/tests/           Markdown specs, each covering a feature or journey group
tests/                 executable Shiplight YAML tests
playwright.config.ts   project-level Playwright config, shared auth, and runtime defaults
auth.setup.ts          shared-account Playwright auth setup, if needed
auth/                  optional auth helpers or per-test login scripts
templates/             reusable YAML statement groups, if any
helpers/               TypeScript helper functions, if any
fixtures/              fixture files, if any
knowledge/             durable notes discovered by agents
test-results/          generated runtime artifacts; do not edit
shiplight-report/      generated reports; do not edit
.shiplight/            local Shiplight state; do not edit

Read the full file on GitHub · 119 lines

Files

What ships with it

10 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.

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.

9d ago First seen · 119 lines · 45 tokens per session scan A 6caae528085b

Subscribe to this mod's changes

create-yaml-tests is a skill published in the GitHub repository ShiplightAI/agent-skills (2 stars, last pushed 2mo ago), licensed MIT. It adds 45 tokens to every session and 1,183 once invoked, about $0.0002 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.

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