Skip to content
Agentmart
Submit a tool

assay

Run assay on a web page you just wrote or changed.

Skill by sickn33

IndexedMIT★ 48,428
Write a review

Chalk Labs

Need help deploying assay?

Chalk Labs sets up agents like this inside real teams: connected to your tools, tested on your data, with a human in the loop where it matters.

Book a call

Install

Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install skill/sickn33-assay

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

Get the weekly diff

The weekly diff: one email a week with new agent tools, notable updates and grade changes, plus security alerts for tools you follow. Double opt-in, one-click unsubscribe.

We use your email only for this newsletter. Privacy

About

Run assay on a web page you just wrote or changed. It opens the page in a real browser, drives every control, and reports where the page contradicts itself. Local browser checks without an LLM API key.

Use cases: backend, ml

No reviews yet. Installed it? Reviews come from verified installers only. How reviews work

Permissions

What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

Tools
No tools found
Secrets
None asked for
Install scripts
None found

Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/assay

What's inside

Skill name
assay
Description
Run assay on a web page you just wrote or changed. It opens the page in a real browser, drives every control, and reports where the page contradicts itself. Local browser checks without an LLM API key.
License
MIT
Instructions
150 lines in SKILL.md · view on GitHub

Files (1)

  • SKILL.md

SKILL.md (first lines)

# Assay

## Overview

A page you have just written has no tests yet. `assay` serves the page locally, opens it in a real Chromium browser through Playwright, finds every control on it, uses all of them, and reports where the page contradicts itself. There is no LLM API key requirement. Browser behavior can vary with application state, timing, browser version and network dependencies; repeated results are evidence only for the tested environment.

Use this skill after you create or change a web page, to run assay on that page and report the one line it prints. The skill reports the result and does not change code because of it unless you ask.

## When to Use This Skill

- Use when you have just created an HTML page and want to know whether its controls work before you move on.
- Use when you changed a page, or the JavaScript or CSS that a page loads, and want to confirm the page still holds together.
- Use when the user asks you to check, QA, or smoke-test a local web page.
- Run it once at the end, after the last edit, on each page you changed. Do not run it while you are still making changes.

## How It Works

### Step 1: Install the CLI once

Install assay from PyPI. The package is named `assay-ui` and the command it installs is `assay`.

```bash
pip install assay-ui
```

It needs Python 3.10 or newer. On the first run assay downloads the Chromium build Playwright uses.

### Step 2: Run assay on the page you changed

Point assay at the page itself and ask for the one-line summary.

```bash
assay <the page you changed> --one-line
```

Point it at a file such as `todo.html` or `dist/index.html`. A folder also works and opens the `index.html` inside it. The page is often a folder or two above the file you edited, so a change to a script or stylesheet still means running assay on the page that loads it. assay needs no LLM API key; initial browser installation and page dependencies may use the network. A small page takes seconds, and a busy one can take a minute or more.

### Step 3: Report the one line assay printed, verbatim

Put assay's output, word for word, as the last thing in your reply. It is already one line, or one line and a short list. Do not summarize it, reformat it, add to it, or write your own version.

A clean run looks like this, with assay's own numbers and wording.

```text
assay: checked todo/todo.html, 8 checks, nothing flagged.
```

A run that flagged something looks like this, followed by a short list.

```text
assay: checked notes/index.html, 12 checks, 4 flagged:
```

Report the line whether it flagged anything or not. Without it, the reader cannot tell a clean page from a check that never ran.

If the command did not run, say so in your own words, name the page, and quote what the shell actually printed. Never describe a check that did not happen as one that passed, and never guess at a cause.

### Step 4: Report the finding and stop

Report what assay found and stop. Do not edit code in response to a finding in the same reply. If the user then asks you to fix it, fix it.

## Examples

### Example 1: A page that checks out clean

**User:** I added a to-do list at `todo/todo.html`. Does it work?

```bash
assay todo/todo.html --one-line
```

```text
assay: checked todo/todo.html, 8 checks, nothing flagged.
```

Report that line as the last thing in the reply, and do not change the page.

### Example 2: A page where assay flagged something

```bash
assay notes/ --one-line
```

```text
assay: checked notes/index.html, 12 checks, 4 flagged:
  - draw on canvas twice, then press Undo twice: it reacted one press late
```

Report the whole line and its short list, say that a finding is a place to look rather than a confirmed bug, and wait for the user to ask before changing anything.

### Example 3: The command did not run

```bash
assay dist/index.html --one-line
```

```text
assay: error: dist/index.html does not exist
```

Say that assay did not run, name the page, and quote the message. Do not report a check that never happened as one that passed.

## Best Practices

- ✅ Run assay once, at the end, on each page you changed.
- ✅ Point it at the built page, such as `dist/index.html`, not at a source template.
- ✅ Print assay's one line exactly as it came out, as the last thing in your reply.
- ✅ When assay flags something, treat it as a place to look and wait to be asked before changing code.
- ❌ Do not run assay while you are still editing the page.
- ❌ Do not summarize, reword, or invent the result, and never report a check that did not run as one that passed.

## Limitations

- assay will not build your project. Point it at built output. Given a source tree, it says so and names the command to run, and it will not run `npm install` for you, because installing dependencies executes their setup scripts.
- assay checks one page. It does not crawl, so run it on each page you changed.
- assay cannot check intent. A control that runs but does the wrong thing usually is not caught, because assay presses what the page offers and reports what followed without knowing what the page is for.
- A finding is a place to look, not a confirmed bug. A control can correctly do nothing in the state it was pressed in, and a value can be limited on purpose.

## Security & Safety Notes

From sickn33/agentic-awesome-skills, MIT.

More from sickn33/agentic-awesome-skills

Signals

Stars
48,428
Forks
7,039
Open issues
0
Last commit (this folder)
Oct 24, 2026 (12 days ago)
Last release
Oct 24, 2026 (12 days ago)

From GitHub (fetched Oct 24, 2026).

Details

License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

More from sickn33

Done for you

Rather not set it up yourself?

Chalk Labs scopes, builds and runs agents for your team: the task audit, the eval harness, the integrations and the weekly ops report. Fixed scope, priced before we start.

See how we build AI agents →Read the case studies

Chalk Labs is a two-founder AI and growth studio. We build AI agents, CRMs and MVPs for Web3 and AI companies, and have shipped 50+ product and token launches.

launches shipped
50+
launches shipped
media placements
500+
media placements
founders on every account
2
founders on every account

Press we've placed: Forbes · CoinDesk · Decrypt · Cointelegraph · The Block

Rahil Jain, Co-founder, Chalk Labs. Ex-Goldman Sachs engineer. You talk to the person who builds it.

Get assay running in your business

Tell us what you want to automate. A founder replies within one working day with a plan, not a pitch deck.

Goes to the Chalk Labs founders, not the newsletter. Privacy

Need help deploying assay?

CallGet help
Cite this page

assay skill. Agent Mart. https://agentmart.dev/skills/sickn33-assay (last updated 2026-10-24)