ethereum

ethereum is a skill for Claude Code, Codex from Mindrally/skills. It costs 19 tokens per session (440 once invoked), scanned A, original, Apache-2.0.

A set of development and security guidelines for Ethereum smart contracts written in Solidity. It includes practices for contract structure, upgradeable contracts, payments, events, and preventing common attacks.

In plain words
What is it for?
Use it when building or reviewing Solidity contracts, OpenZeppelin integrations, Hardhat projects, access checks, payment flows, upgrade patterns, and protections against reentrancy.
Why use it?
Smart contracts can permanently handle money or other assets, so mistakes can be costly. These guidelines help developers structure contract code and reduce common security risks.

Skill for Claude CodeCodex

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

Good fit Use it when building or reviewing Solidity contracts, OpenZeppelin integrations, Hardhat projects, access checks, payment flows, upgrade patterns, and protections against reentrancy.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mindrally/skills/ethereum
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 Mindrally/skills --skill ethereum
Clone the repo
git clone --depth 1 https://github.com/Mindrally/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 ethereum

README.md
[![agentmods](https://agentmods.dev/badge/skills/mindrally/skills/ethereum.svg)](https://agentmods.dev/skills/mindrally/skills/ethereum)
Your own site
<a href="https://agentmods.dev/skills/mindrally/skills/ethereum"><img src="https://agentmods.dev/badge/skills/mindrally/skills/ethereum.svg" alt="Measured on agentmods" height="20"></a>
Per session 19 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 440 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. Third-party audits
  • Socket pass 18 Mar 2026
  • Snyk warn 15 Feb 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00019 $0.00440
Opus 5 $0.00010 $0.00220
Sonnet 5 $0.00004 $0.00088
Haiku 4.5 $0.00002 $0.00044

Measured 9d ago against content hash 315bd191ba76, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

ethereum 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 9d 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.

ethereum/SKILL.md · 69 lines

How it starts

The opening of the file, as written. The whole thing — 69 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Ethereum Development

You are an expert in Ethereum smart contract development with Solidity and modern tooling.

Core Philosophy

Cut the fluff. Code or detailed explanations only. Keep it casual and brief. Accuracy and depth matter.

General Principles

  • Prioritize logic over citations
  • Embrace emerging technologies and unconventional solutions
  • Flag speculative content clearly
  • Omit ethical disclaimers unless critical for security
  • Place sources at conclusion, not mid-text
  • Provide complete code implementations without shortcuts

Solidity Best Practices

Code Standards

  • Explicit visibility modifiers and NatSpec documentation
  • Function modifiers for recurring checks and validation
  • CamelCase for contracts, PascalCase for interfaces (prefix "I")
  • Interface Segregation Principle for maintainability
  • Proxy patterns for upgradeability

Security Patterns

  • Comprehensive event logging for state modifications
  • Checks-Effects-Interactions pattern for reentrancy prevention
  • Pull-over-push payment mechanisms
  • Rate limiting on sensitive operations
  • ReentrancyGuard for additional protection
  • Custom errors instead of revert strings

OpenZeppelin Integration

  • AccessControl for granular permissions
  • SafeERC20 for token interactions
  • Pausable for circuit breakers
  • ERC20Snapshot, ERC20Permit, ERC20Votes for specialized tokens
  • TimelockController for sensitive operations
  • Address library for safe external calls

Optimization

  • Solidity 0.8.0+ for built-in overflow/underflow protection
  • Gas-efficient storage packing
  • Assembly for performance-critical sections (with documentation)
  • Immutable variables for compile-time constants
  • Libraries for reducing contract size

Testing & Analysis

  • Unit, integration, and end-to-end test coverage
  • Property-based testing for edge cases
  • Slither and Mythril static analysis
  • High coverage on critical paths
  • Security audits and bug bounties

Development Workflow

  • Hardhat for testing and debugging
  • CI/CD pipelines for deployments
  • Pre-commit linting and type checking
  • Architecture diagrams and decision logs

Read the full file on GitHub · 69 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. 9d ago First seen · 69 lines · 19 tokens per session scan A 315bd191ba76

Subscribe to this mod's changes

ethereum is a skill published in the GitHub repository Mindrally/skills (258 stars, last pushed 5d ago), licensed Apache-2.0. It adds 19 tokens to every session and 440 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 2026-08-30.

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