web3_security

A set of security guidelines for Web3, blockchain, and decentralized application development. Web3 applications use blockchain networks and may manage digital assets or transactions.

In plain words
What is it for?
It is for reviewing or guiding the security of Web3, blockchain, and decentralized applications.
Why use it?
It helps developers account for common security weaknesses when building software that interacts with blockchain networks. The description does not specify which vulnerabilities or practices it covers.

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/0xjcf/mcp_codeanalysis/web3_security
Clone the repo
git clone --depth 1 https://github.com/0xjcf/MCP_CodeAnalysis

Made for: Cursor.

Per session 1,416 This file is loaded in full into every session.
When invoked 1,416 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.01416 $0.01416
Opus 5 $0.00708 $0.00708
Sonnet 5 $0.00283 $0.00283
Haiku 4.5 $0.00142 $0.00142

Measured yesterday against content hash ad90fc6219ce, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

web3_security 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 yesterday.

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/web3_security/web3_security.mdc · 187 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. yesterday First seen · 187 lines · 1,416 tokens per session scan A ad90fc6219ce

Subscribe to this mod's changes

web3_security is a cursor rule published in the GitHub repository 0xjcf/MCP_CodeAnalysis (7 stars, last pushed 7mo ago), with no licence file. It adds 1,416 tokens to every session, about $0.0071 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.