agent-playtest

agent-playtest is a skill for Claude Code, Codex from jamesyang124/agent-skills. It costs 187 tokens per session (2,251 once invoked), scanned A, original, MIT.

A browser-based playtesting workflow for interactive websites, games, 3D worlds, galleries, and scenes. It has agents interact with each item, save screenshots and input logs, and write descriptions supported by what they observed.

In plain words
What is it for?
Use it to play through catalog items, collect screenshot evidence, document observed behavior, audit descriptions, and report disagreements or blockers.
Why use it?
Publisher descriptions may be missing, inaccurate, or generic. Evidence from actual interaction helps separate observed facts from supplied claims and records items that could not be tested.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents.

Good fit Use it to play through catalog items, collect screenshot evidence, document observed behavior, audit descriptions, and report disagreements or blockers.

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Install with agentmods
npx agentmods add skills/jamesyang124/agent-skills/agent-playtest
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 jamesyang124/agent-skills --skill agent-playtest
Clone the repo
git clone --depth 1 https://github.com/jamesyang124/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.

agentmods badge for agent-playtest

README.md
[![agentmods](https://agentmods.dev/badge/skills/jamesyang124/agent-skills/agent-playtest/github.svg)](https://agentmods.dev/skills/jamesyang124/agent-skills/agent-playtest)
Your own site
<a href="https://agentmods.dev/skills/jamesyang124/agent-skills/agent-playtest"><img src="https://agentmods.dev/badge/skills/jamesyang124/agent-skills/agent-playtest/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 agent-playtest

Your own site · 80×15
<a href="https://agentmods.dev/skills/jamesyang124/agent-skills/agent-playtest"><img src="https://agentmods.dev/badge/skills/jamesyang124/agent-skills/agent-playtest.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 187 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,251 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00187 $0.02251
Opus 5.5 $0.00075 $0.00900
Sonnet 5.5 $0.00037 $0.00450
Haiku 4.5 $0.00019 $0.00225

Measured 20d ago against content hash 32b0585d7acb, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

agent-playtest 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 20d ago.

The scan reads SKILL.md. This mod also ships 11 executable files (scripts/_common.py, scripts/contact_sheets.py, scripts/frame_diff.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

own-skills/agent-playtest/SKILL.md · 127 lines

How it starts

The opening of the file, as written. The whole thing — 127 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent playtest: closed-loop play → screenshot evidence → described, audited data

Many catalog entries (rooms, games, worlds, apps) have publisher text that is wrong, empty, or templated. This skill gets an observed description: an agent actually opens each item, plays it, records what it saw, and writes a description in which every claim cites a screenshot. The output stays separate from the publisher's declared data and never overwrites it. Disagreements are recorded and handed to whoever owns the catalog.

Every item goes through this pipeline:

plan  →  dispatch N player subagents  →  play (closed loop)  →  audit screenshots  →  validate  →  spot-check  →  report
                                  ↘ blockers log (anything that could not be done: record it and continue) ↙

Roles

Role Who Does
Orchestrator the calling session writes the plan and brief, dispatches players, audits, validates, samples the spot-check, reports, keeps the blockers log
Player 1 subagent per slice of items (default ≤ 4 in parallel) plays its items in order with one browser session, writes playtest.json, shots/, description.json
Human the person running it (optional) spot-checks descriptions; plays hard items in human-demo mode

Evidence contract

Read references/evidence-review.md before capture or review: content-only screenshots, coverage by content type, declared/observed separation, timing limits, model roles and portable batches. It takes precedence over historical capture/report examples. Keep database schemas unchanged unless separately authorized.

Before you start (orchestrator)

  1. Pick a browser adapter. Read references/browser-adapters.md. It lists the capabilities a player needs and how ego-browser, Playwright and Chrome DevTools provide each one. Record the choice in the campaign entry.
  2. Pick or write a site profile. Site-specific rules (URLs, metadata source, paywalls, device gates, embed origins) go in profiles/<site>.md, never in the generic protocol. profiles/viverse.md is the worked example.
  3. Set up the workspace (layout in references/data-schema.md). Then add a campaigns.json entry and write archive/<campaign>/plan.json (templates/plan.example.json).
  4. Write the brief from templates/agent_brief.md, filling in the adapter, profile, paths, and any rules specific to this campaign.

Read the full file on GitHub · 127 lines

Files

What ships with it

32 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.

  1. 20d ago First seen · 127 lines · 187 tokens per session scan A 32b0585d7acb

Subscribe to this mod's changes

agent-playtest is a skill published in the GitHub repository jamesyang124/agent-skills (2 stars, last pushed 7d ago), licensed MIT. It adds 187 tokens to every session and 2,251 once invoked, about $0.0007 per session on Opus 5.5. 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 2026-10-06.

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