evm-audit-erc721

evm-audit-erc721 is a skill for Claude Code, Codex from austintgriffith/evm-audit-skills. It costs 78 tokens per session (149 once invoked), scanned A, original, MIT.

A checklist for auditing EVM smart contracts that use ERC721 or ERC1155 tokens. EVM means the Ethereum Virtual Machine, and ERC721/ERC1155 are common token standards, especially for NFTs.

In plain words
What is it for?
Reviewing protocols that interact with arbitrary NFTs, including wrapped, upgradeable, fractional, paused, blacklisted, or permit-enabled collections.
Why use it?
It helps auditors check unusual token behaviour and contract risks that a basic review may miss.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Reviewing protocols that interact with arbitrary NFTs, including wrapped, upgradeable, fractional, paused, blacklisted, or permit-enabled collections.

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Install with agentmods
npx agentmods add skills/austintgriffith/evm-audit-skills/evm-audit-erc721
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 austintgriffith/evm-audit-skills --skill evm-audit-erc721
Clone the repo
git clone --depth 1 https://github.com/austintgriffith/evm-audit-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 evm-audit-erc721

README.md
[![agentmods](https://agentmods.dev/badge/skills/austintgriffith/evm-audit-skills/evm-audit-erc721/github.svg)](https://agentmods.dev/skills/austintgriffith/evm-audit-skills/evm-audit-erc721)
Your own site
<a href="https://agentmods.dev/skills/austintgriffith/evm-audit-skills/evm-audit-erc721"><img src="https://agentmods.dev/badge/skills/austintgriffith/evm-audit-skills/evm-audit-erc721/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 evm-audit-erc721

Your own site · 80×15
<a href="https://agentmods.dev/skills/austintgriffith/evm-audit-skills/evm-audit-erc721"><img src="https://agentmods.dev/badge/skills/austintgriffith/evm-audit-skills/evm-audit-erc721.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 78 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 149 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 $0.00078 $0.00149
Opus 5.5 $0.00031 $0.00060
Sonnet 5.5 $0.00016 $0.00030
Haiku 4.5 $0.00008 $0.00015

Measured 2mo ago against content hash 7eca29e20fc5, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

evm-audit-erc721 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 2mo 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.

evm-audit-erc721/SKILL.md · 13 lines

What it actually says

ERC721/ERC1155 Audit Skill

Overview

Non-obvious security edge cases for protocols interacting with ERC721 and ERC1155 tokens. Based on real-world token behaviors that have caused exploits.

Reference Files

  • references/checklist.md — Full audit checklist, load this when auditing NFT-related protocols
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. 2mo ago First seen · 13 lines · 78 tokens per session scan A 7eca29e20fc5

Subscribe to this mod's changes

evm-audit-erc721 is a skill published in the GitHub repository austintgriffith/evm-audit-skills (12 stars, last pushed 1mo ago), licensed MIT. It adds 78 tokens to every session and 149 once invoked, about $0.0003 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 2026-08-31.