wasm-pack-build

wasm-pack-build is a skill for Claude Code from gertsylvest/meta-team. It costs 76 tokens per session (1,030 once invoked), scanned A, original, MIT.

A fixed build process for compiling Rust code into WebAssembly, a format that runs in web browsers, for browser audio projects.

In plain words
What is it for?
Use it to verify tools, build a Rust crate for the web, optimize the WebAssembly output, and inspect the resulting module.
Why use it?
It makes builds consistent across developer machines and checks the finished module for required exports, SIMD support, and validity.

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 bash build.sh ./rust/audio-wasm.

Good fit Use it to verify tools, build a Rust crate for the web, optimize the WebAssembly output, and inspect the resulting module.

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-pack-build

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-pack-build

README.md
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Your own site
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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-pack-build

Your own site · 80×15
<a href="https://agentmods.dev/skills/gertsylvest/meta-team/wasm-pack-build"><img src="https://agentmods.dev/badge/skills/gertsylvest/meta-team/wasm-pack-build.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 76 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,030 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 $0.00076 $0.01030
Opus 5 $0.00038 $0.00515
Sonnet 5 $0.00015 $0.00206
Haiku 4.5 $0.00008 $0.00103

Measured 11d ago against content hash a98e0f45de1e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

wasm-pack-build 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 (build.sh), 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-pack-build/SKILL.md · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

wasm-pack Build

The canonical Rust→WASM build path for browser audio. Builds with wasm-pack against wasm32-unknown-unknown, applies wasm-opt for size and performance, and runs wasm-module-inspect on the output to confirm exports are minimal, SIMD is present, and the module validates.

The flag set is fixed by this skill so every Rust WASM build in the project produces a binary with the same characteristics — no ad-hoc differences between developer machines or CI.

Requirements

  • rustup with stable toolchain and the wasm32-unknown-unknown target:
    rustup target add wasm32-unknown-unknown
    
  • wasm-pack — install via cargo install wasm-pack or from https://rustwasm.github.io/wasm-pack/installer/.
  • wasm-opt (Binaryen) — install via brew install binaryen (macOS) or apt install binaryen (Linux).
  • The wasm-module-inspect skill from this library (the script invokes it for the final verification step).

What it does

  1. Verifies prerequisites (wasm-pack, wasm-opt, target installed).
  2. Sets RUSTFLAGS="-C target-feature=+simd128" so WASM SIMD is enabled.
  3. Runs wasm-pack build --target web --release (or --dev if --dev is passed) on the crate.
  4. Runs wasm-opt -O3 --enable-simd <pkg>/<crate>_bg.wasm -o <same> to apply Binaryen's optimisation pass over the wasm-bindgen-emitted module.
  5. Invokes wasm-module-inspect on the optimised .wasm.

Release builds also implicitly use the project's [profile.release] settings — the crate is expected to declare panic = "abort", lto = "fat", codegen-units = 1, opt-level = 3 per the rust-audio-engineer agent's standards.

Instructions

The arguments are in $ARGUMENTS. Pass them directly to the build script:

bash "$(dirname "$0")/build.sh" $ARGUMENTS

Argument 1 is the crate directory. Optional second argument --dev switches to a debug build with source maps for browser debugging.

Output sections

Section What it reports
PREREQ Whether wasm-pack, wasm-opt, and the wasm32 target are present
BUILD wasm-pack invocation result
OPTIMISE wasm-opt size reduction
INSPECT Full output of wasm-module-inspect

Read the full file on GitHub · 74 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 · 74 lines · 76 tokens per session scan A a98e0f45de1e

Subscribe to this mod's changes

wasm-pack-build is a skill published in the GitHub repository gertsylvest/meta-team (5 stars, last pushed 1mo ago), licensed MIT. It adds 76 tokens to every session and 1,030 once invoked, about $0.0004 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.