wasm-worklet-smoke

wasm-worklet-smoke is a skill for Claude Code from gertsylvest/meta-team. It costs 64 tokens per session (1,384 once invoked), scanned A, original, MIT.

An automated browser smoke test for a WebAssembly audio engine built with Emscripten and AudioWorklet, the browser feature used to run audio processing separately from the page.

In plain words
What is it for?
Use it to build the WASM target, serve it locally, open it in headless Chrome, start the audio engine, check for errors, and verify that the output is not silent.
Why use it?
It catches browser-only failures such as loading errors, worklet setup problems, console errors, and an engine that runs without producing sound.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: positional $N argument.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is node tests/smoke_wasm.js --no-rebuild.

Good fit Use it to build the WASM target, serve it locally, open it in headless Chrome, start the audio engine, check for errors, and verify that the output is not silent.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/gertsylvest/meta-team
agentmods
npx agentmods add skills/gertsylvest/meta-team/wasm-worklet-smoke

Made for: Claude Code.

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 wasm-worklet-smoke

README.md
[![agentmods](https://agentmods.dev/badge/skills/gertsylvest/meta-team/wasm-worklet-smoke/github.svg)](https://agentmods.dev/skills/gertsylvest/meta-team/wasm-worklet-smoke)
Your own site
<a href="https://agentmods.dev/skills/gertsylvest/meta-team/wasm-worklet-smoke"><img src="https://agentmods.dev/badge/skills/gertsylvest/meta-team/wasm-worklet-smoke/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 wasm-worklet-smoke

Your own site · 80×15
<a href="https://agentmods.dev/skills/gertsylvest/meta-team/wasm-worklet-smoke"><img src="https://agentmods.dev/badge/skills/gertsylvest/meta-team/wasm-worklet-smoke.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 64 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,384 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 $0.00064 $0.01384
Opus 5 $0.00032 $0.00692
Sonnet 5 $0.00013 $0.00277
Haiku 4.5 $0.00006 $0.00138

Measured 11d ago against content hash 872731a81529, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

wasm-worklet-smoke 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 11d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (smoke.js), 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.

library/skills/wasm-worklet-smoke/SKILL.md · 112 lines

How it starts

The opening of the file, as written. The whole thing — 112 lines — stays where its author put it; the contents beside it link to each section on GitHub.

WASM Worklet Smoke Test

Automated headless verification of an Emscripten + AudioWorklet build. Catches the class of failures that require a browser to surface: worklet registration failures, Emscripten runtime errors (self is not defined, fetch is not a function), WASM instantiation failures, and silent audio output.

Covers the gaps in a basic log-message-only smoke test: verifies actual audio output is non-silent, verifies the parameter message path, and catches all console.error / unhandled rejection events.

Requirements

  • Node.js 18+ and npm
  • Playwright with Chromium: npm install playwright && npx playwright install chromium
  • Python 3 (for the HTTP server)
  • make with a WASM build target (default: synth-wasm)
  • Project setup: main.js must expose window.__audioCtx and window.__synthNode for audio verification (see Project Setup below)

Project setup

The audio verification step reads audioCtx and synthNode from window. The IIFE in main.js hides these by default. Add the following lines inside the IIFE after the AudioWorkletNode is connected and ready:

// Expose for automated testing (safe: AudioWorkletGlobalScope is isolated)
if (typeof window !== 'undefined') {
    window.__audioCtx  = audioCtx;
    window.__synthNode = synthNode;
}

Guard with window.__TEST_MODE if you prefer to enable this only during tests:

if (window.__TEST_MODE) {
    window.__audioCtx  = audioCtx;
    window.__synthNode = synthNode;
}

If the audio check is not needed, pass --no-audio-check to skip this step and the project setup requirement.

Instructions

Arguments are in $ARGUMENTS. Pass them directly to the smoke test script:

node "$(dirname "$0")/smoke.js" $ARGUMENTS

What the test verifies

Check What it catches
Build succeeds Compilation errors in any source file, missing include paths
Server starts Broken asset copy, missing synth.js / synth.wasm
WASM engine initialised log Worklet registered, WASM instantiated, onRuntimeInitialized fired
Zero console.error events Any runtime JS error in the worklet or main thread
Zero pageerror events Uncaught exceptions
Non-silent audio (AnalyserNode) Silent engine (stuck envelope, null DSP output, broken computeSynth call)
Expected fundamental frequency Wrong oscillator frequency, detuning bug, wrong default param

Read the full file on GitHub · 112 lines

Files

What ships with it

1 file 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. 11d ago First seen · 112 lines · 64 tokens per session scan A 872731a81529

Subscribe to this mod's changes

wasm-worklet-smoke is a skill published in the GitHub repository gertsylvest/meta-team (5 stars, last pushed 1mo ago), licensed MIT. It adds 64 tokens to every session and 1,384 once invoked, about $0.0003 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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