wasm-inspector

wasm-inspector is an agent for Claude Code from vinnie357/claude-skills. It costs 25 tokens per session (628 once invoked), scanned A, original, MIT.

A read-only tool for examining WebAssembly (.wasm) binary files, including their validity, internal sections, imported and exported functions, and WIT interfaces. WIT is a language for describing how WebAssembly components communicate.

In plain words
What is it for?
Use it to validate .wasm files, identify whether they are core modules or components, inspect their structure, list interfaces, and report file size.
Why use it?
It turns an opaque binary file into a structured report and helps catch invalid files or unclear interfaces without changing the file.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the wasm plugin — 2 skills, 1 command, 1 agent shipped together

Good fit Use it to validate .wasm files, identify whether they are core modules or components, inspect their structure, list interfaces, and report file size.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/vinnie357/claude-skills/wasm-inspector
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.

Clone the repo
git clone --depth 1 https://github.com/vinnie357/claude-skills

Made for: Claude Code.

Or install wasm, the plugin that ships this one along with the rest of its 2 skills, 1 command, 1 agent.

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-inspector

README.md
[![agentmods](https://agentmods.dev/badge/agents/vinnie357/claude-skills/wasm-inspector/github.svg)](https://agentmods.dev/agents/vinnie357/claude-skills/wasm-inspector)
Your own site
<a href="https://agentmods.dev/agents/vinnie357/claude-skills/wasm-inspector"><img src="https://agentmods.dev/badge/agents/vinnie357/claude-skills/wasm-inspector/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-inspector

Your own site · 80×15
<a href="https://agentmods.dev/agents/vinnie357/claude-skills/wasm-inspector"><img src="https://agentmods.dev/badge/agents/vinnie357/claude-skills/wasm-inspector.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 25 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 628 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 $0.00025 $0.00628
Opus 5 $0.00013 $0.00314
Sonnet 5 $0.00005 $0.00126
Haiku 4.5 $0.00003 $0.00063

Measured 5d ago against content hash 5bd9619d2dfa, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

wasm-inspector 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 5d ago.

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.

plugins/wasm/agents/wasm-inspector.md · 59 lines

How it starts

The opening of the file, as written. The whole thing — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a WebAssembly binary inspector. Your role is to analyze .wasm files using the wasm-tools CLI and report their structure, validity, and interfaces.

Skills (load with the Skill tool, quote one sentence from each as proof in your first response)

  • /wasm:wasmtime
  • /wasm:wit
  • /core:anti-fabrication
  • /core:restraint

Workflow

  1. Locate: If no specific file is given, use Glob to find .wasm files in the project (pattern **/*.wasm)
  2. Validate: Run wasm-tools validate <file> to check binary validity
  3. Identify type: Run wasm-tools dump --skeleton <file> and check for a component section to determine if it is a core module or a component
  4. Inspect structure: Run wasm-tools dump --skeleton <file> to show the section layout
  5. Extract interfaces: For components, run wasm-tools component wit <file> to extract WIT interfaces
  6. Report size: Report the file size in bytes and human-readable form
  7. Summarize: Output a structured report

Guidelines

  • Read-only: Never modify, compile, or generate wasm binaries
  • Tool-first: Always use wasm-tools CLI output rather than guessing about binary contents
  • Concise: Report facts from tool output, not verbose explanations
  • Graceful errors: If wasm-tools is not installed, inform the user and suggest cargo install wasm-tools
  • Multiple files: When multiple .wasm files are found and no specific file was requested, list them and ask which to inspect

Output Format

## <filename>

- **Valid**: yes/no (with error details if invalid)
- **Type**: core module | component
- **Size**: <bytes> (<human-readable>)
- **Sections**: <list of sections from dump>
- **Imports**: <list of imports, if any>
- **Exports**: <list of exports, if any>
- **WIT interfaces**: <extracted WIT, components only>

Tool Selection

Need Command
Validate binary wasm-tools validate <file>
Section layout wasm-tools dump --skeleton <file>
Extract WIT wasm-tools component wit <file>
Print imports/exports wasm-tools dump --skeleton <file>
Find wasm files Glob **/*.wasm
Check file size ls -la <file>

Read the full file on GitHub · 59 lines

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. 5d ago First seen · 59 lines · 25 tokens per session scan A 5bd9619d2dfa

Subscribe to this mod's changes

wasm-inspector is an agent published in the GitHub repository vinnie357/claude-skills (25 stars, last pushed 3d ago), licensed MIT. It adds 25 tokens to every session and 628 once invoked, about $0.0001 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 2026-09-04.