Web Application Testing
anthropics/skills
Tests local web applications with Python Playwright scripts, checking frontend behavior, capturing screenshots and reading browser console logs.
Plan E2E verification and reproducible evidence, audit test value, or test an isolated system before implementation.
Install Testing
$ npx skills add yielded-dev/agent --skill testing -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install yielded-dev/agent testing --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/yielded-dev/agent.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/testing .claude/skills/testing && 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 "testing" agent skill from https://github.com/yielded-dev/agent/tree/main/.agents/skills/testing into .claude/skills/testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "testing", 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/yielded-dev/agent/tree/main/.agents/skills/testingType 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 yielded-dev/agent --skill testing -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install yielded-dev/agent testing --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/yielded-dev/agent.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/testing .agents/skills/testing && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "testing" agent skill from https://github.com/yielded-dev/agent/tree/main/.agents/skills/testing into .agents/skills/testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "testing", 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 yielded-dev/agent --skill testing -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install yielded-dev/agent testing --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/yielded-dev/agent.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/testing .cursor/skills/testing && 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 "testing" agent skill from https://github.com/yielded-dev/agent/tree/main/.agents/skills/testing into .cursor/skills/testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "testing", 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/yielded-dev/agent.git --path .agents/skills/testing--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 yielded-dev/agent --skill testing -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install yielded-dev/agent testing --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/yielded-dev/agent.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/testing .gemini/skills/testing && 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 "testing" agent skill from https://github.com/yielded-dev/agent/tree/main/.agents/skills/testing into .gemini/skills/testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "testing", 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 yielded-dev/agent testingInstalls 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 yielded-dev/agent --skill testing -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/yielded-dev/agent.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/testing .github/skills/testing && 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 "testing" agent skill from https://github.com/yielded-dev/agent/tree/main/.agents/skills/testing into .github/skills/testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "testing", 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 yielded-dev/agent --skill testing -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install yielded-dev/agent testing --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/yielded-dev/agent.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/testing .opencode/skills/testing && 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 "testing" agent skill from https://github.com/yielded-dev/agent/tree/main/.agents/skills/testing into .opencode/skills/testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "testing", 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
testing- GitHub stars
- 132
- Token cost
- ~487 tokens
- SKILL.md length
- 244 words
- Files
- 9 (incl. references)
- Skills in repo
- 3
- Repo updated
- First seen
- Licence
- MIT
At a glance
Plan E2E verification and reproducible evidence, audit test value, or test an isolated system before implementation.
- Tasks that involve End-to-end testing
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Testing is an agent skill from yielded-dev/agent. Plan E2E verification and reproducible evidence, audit test value, or test an isolated system before implementation.
Its SKILL.md is about 490 tokens, which your agent loads only when the skill is triggered. The skill folder holds 10 other files, including reference files (for example `.dev-kit-origin.json`, `agents/openai.yaml` and `references/e2e.md`).
It sits in Testing & QA, covering End-to-end testing. The repository describes itself as: Yielded Agent: an agent harness toolkit for TypeScript, built on Effect and Effect AI. The licence is MIT.
When your agent uses it
- Tasks that involve End-to-end testing
Example prompts
- “/testing”
What it can do on your machine
Read from SKILL.md and the folder at commit fbfc583. 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
No URLs in SKILL.md.
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
Testing loads about 487 tokens when it runs, and up to ~3.5k if it reads all its reference files. Until then it costs about 31 tokens; SKILL.md has 244 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 yielded-dev/agent at commit fbfc583, republished under its MIT licence (© yielded-dev). 244 words, ~487 tokens.
Download SKILL.mdSave it as
.claude/skills/testing/SKILL.md (or your agent's skills folder). This skill also uses 8 other files; get the full folder from GitHub.- name
- testing
- description
- Plan E2E verification and reproducible evidence, audit test value, or test an isolated system before implementation.
- license
- MIT
Testing
Default to writing no new tests or test infrastructure. Verification remains required: use existing checks and direct observation of the running workflow. Strongly prefer E2E as the sole testing mechanism for complex features; running a workflow and saving evidence usually needs no new automated suite.
Never write unit tests after writing the implementation. Never replace an unnecessary unit test with a larger integration or E2E test. Read test selection before writing or expanding any test, fixture, mock, harness, or reporting code, including temporary scripts.
Before substantial work, identify the requested observable outcomes and the cheapest sufficient proof for each in working notes. Add acceptance scope only for a requirement or a concrete risk introduced by the change. Simple edits need no separate acceptance document or new tests.
- Plan or run E2E verification: workflows and artifacts, then use the existing consumer, CLI, adapter, or deployed acceptance entrypoint. Every run must finish with a verifiable artifact and enough information to repeat it.
- Audit existing tests: test selection.
- Isolation is necessary, or a human requests TDD: first read failure-first development and boundaries and placement. Write all the ways the scoped system could fail, then the failing tests, then the code.
An incident URL or explicit test request does not waive necessity or test-first order. Keep the final suite green and stop when the requested outcomes have sufficient evidence. Test count, coverage, and artifact volume are not goals.
© yielded-dev, 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 8 other files (references) in .agents/skills/testing of yielded-dev/agent.
- SKILL.md
- .dev-kit-origin.json
- LICENSE
- NOTICE
- agents/openai.yaml
- references/e2e.md
- references/selection.md
- references/tdd.md
- references/test-design.md
Open the folder on GitHubat commit fbfc583
Compare with similar skills
Testing 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 |
|---|---|---|---|---|---|---|
| Testing this skillyielded-dev/agent | 132 | — | ~487 | Automated safety check: Pass | MIT | |
| Web Application Testinganthropics/skills | 180k | 51 repos | ~966 | Automated safety check: Pass | Apache-2.0 | |
| TDD WorkflowhellangleZ/burn-in-cceverywhere-ralph | 112 | 11 repos | ~2.4k | Automated safety check: Pass | None | |
| Uloop Replay Inputkurotu/VRCQuestTools | 373 | 3 repos | ~615 | Automated safety check: Pass | MIT | |
| Ui4 Convert Testspayloadcms/payload | 45k | — | ~3.5k | Automated safety check: Pass | MIT | |
| E2Estackia/rtp2httpd | 2.2k | — | ~517 | Automated safety check: Pass | GPL-2.0 |
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Related
Categories
Questions about Testing
What does Testing do?
Plan E2E verification and reproducible evidence, audit test value, or test an isolated system before implementation. Testing is an agent skill from yielded-dev/agent. Plan E2E verification and reproducible evidence, audit test value, or test an isolated system before implementation.
When should I use Testing?
Testing fits situations like: tasks that involve End-to-end testing.
How do I install Testing in Claude Code?
Run `npx skills add yielded-dev/agent --skill testing -a claude-code`. Or copy the skill folder (.agents/skills/testing in yielded-dev/agent) into .claude/skills/testing in your project. Claude Code loads it when a task matches its description.
How do I install Testing in Codex?
Run `npx skills add yielded-dev/agent --skill testing -a codex`. Or copy the skill folder (.agents/skills/testing in yielded-dev/agent) into .agents/skills/testing in your project. Codex loads it when a task matches its description.
Can I use Testing 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 yielded-dev/agent --skill testing -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/testing, .gemini/skills/testing, .github/skills/testing and .opencode/skills/testing in your project.
What does Testing need to run?
SKILL.md names no scripts, command-line tools or credentials: Testing is instructions for the agent only.
Does Testing access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Testing 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 Testing use?
Testing is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Testing use?
About 487 tokens (SKILL.md is roughly 1.9k 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 3k tokens, read only when the agent opens those files.
What are the alternatives to Testing?
Skills that share tags, products or a category with Testing: Web Application Testing (anthropics/skills, 180k stars), TDD Workflow (hellangleZ/burn-in-cceverywhere-ralph, 112 stars), Uloop Replay Input (kurotu/VRCQuestTools, 373 stars) and Ui4 Convert Tests (payloadcms/payload, 45k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Testing?
yielded-dev (a GitHub organization) maintains it in yielded-dev/agent, which has 132 GitHub stars. The repository holds 3 skills in this directory. The repository was last updated on October 7, 2026.
Source: yielded-dev/agent on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.