general

A set of coding rules for building Ethereum software, especially smart contracts written in Solidity. Ethereum is a blockchain platform, and smart contracts are programs that run on it.

In plain words
What is it for?
Use it when writing or reviewing Solidity contracts, including access control, token handling, validation, events, and storage or gas decisions.
Why use it?
It gives the coding agent consistent standards for safety, readability, and gas use, while warning against common mistakes such as unsafe token transfers or exposed keys.

Cursor rule for Cursor

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.

agentmods
npx agentmods add rules/ccashwell/evm-cortex/general
Clone the repo
git clone --depth 1 https://github.com/ccashwell/evm-cortex

Made for: Cursor.

Per session 521 This file is loaded in full into every session.
When invoked 521 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.00521 $0.00521
Opus 5 $0.00260 $0.00260
Sonnet 5 $0.00104 $0.00104
Haiku 4.5 $0.00052 $0.00052

Measured 2d ago against content hash 1519f14aabb7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

general 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 2d 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.

.cursor/rules/general.mdc · 61 lines

How it starts

The opening of the file, as written. The whole thing — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.

EVM Cortex - Ethereum Protocol Engineering Standards

You are part of EVM Cortex, an Ethereum protocol engineering squad with specialized agents, skills, hooks, and rules.

Solidity Standards

Code Style

  • Custom errors over require strings (gas + clarity)
  • Named imports: import {ERC20} from "@openzeppelin/..."
  • NatSpec on ALL public/external functions
  • Constants: UPPER_SNAKE_CASE. Immutables: camelCase or UPPER_SNAKE_CASE
  • Events: PascalCase past tense (Deposited, Transferred)
  • Max 400 lines per contract file. Extract libraries for reuse.
  • Functions under 50 lines. No more than 4 levels of nesting.

Security

  • Checks-effects-interactions pattern on all state-changing functions
  • ReentrancyGuard on functions with external calls
  • SafeERC20 for ALL token transfers
  • Ownable2Step over Ownable
  • Input validation at all entry points
  • USDC has 6 decimals. USDT does not return bool. Use SafeERC20.
  • Never hardcode private keys or API keys
  • Never trust tx.origin for authorization

Gas Awareness

  • Storage packing: fit variables into 32-byte slots
  • Prefer calldata over memory for read-only parameters
  • Use immutable/constant for values set once
  • Cache storage reads in memory when accessed multiple times
  • Use unchecked only when overflow is mathematically impossible

Testing (Foundry)

  • TDD: write test first, implement, then optimize
  • Test naming: test_Function_Condition_Result, test_RevertWhen_Condition
  • Fuzz test all math operations
  • Fork-test all external protocol integrations
  • Gas snapshots: forge snapshot to track regressions
  • Target 90%+ coverage on security-critical paths

Conventions

  • Say "onchain" not "on-chain"
  • Never hallucinate contract addresses -- verify with cast code
  • Foundry is the default toolchain (not Hardhat)
  • OpenZeppelin Contracts v5 as the standard library

Git Conventions

  • Commit format: <type>: <description>
  • Types: feat, fix, refactor, docs, test, chore, perf, ci, audit
  • Keep commits atomic and focused

Read the full file on GitHub · 61 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. 2d ago First seen · 61 lines · 521 tokens per session scan A 1519f14aabb7

Subscribe to this mod's changes

general is a cursor rule published in the GitHub repository ccashwell/evm-cortex (127 stars, last pushed 22d ago), licensed MIT. It adds 521 tokens to every session, about $0.0026 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.