blockchain-security

blockchain-security is a skill for Claude Code, Codex from j4flmao/agent-skills. It costs 203 tokens per session (5,325 once invoked), scanned A, original, MIT.

A guide to security analysis for blockchain systems and smart contracts, including financial attack risks and emergency response.

In plain words
What is it for?
Use it for smart-contract audits, threat models, formal checks, incident response, bug-bounty planning, and analysis of attacks such as reentrancy, flash loans, and oracle manipulation.
Why use it?
Blockchain code can lose assets permanently when attackers exploit contract bugs, price feeds, permissions, or economic incentives.

Skill for Claude CodeCodex

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

Good fit Use it for smart-contract audits, threat models, formal checks, incident response, bug-bounty planning, and analysis of attacks such as reentrancy, flash loans, and oracle manipulation.

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Install with agentmods
npx agentmods add skills/j4flmao/agent-skills/blockchain-security
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 j4flmao/agent-skills --skill blockchain-security
Clone the repo
git clone --depth 1 https://github.com/j4flmao/agent-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 blockchain-security

README.md
[![agentmods](https://agentmods.dev/badge/skills/j4flmao/agent-skills/blockchain-security.svg)](https://agentmods.dev/skills/j4flmao/agent-skills/blockchain-security)
Your own site
<a href="https://agentmods.dev/skills/j4flmao/agent-skills/blockchain-security"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/blockchain-security.svg" alt="Measured on agentmods" height="20"></a>
Per session 203 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,325 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
  • 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 $0.00203 $0.05325
Opus 5 $0.00102 $0.02662
Sonnet 5 $0.00041 $0.01065
Haiku 4.5 $0.00020 $0.00532

Measured 4d ago against content hash c2a4c9956f71, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

blockchain-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 4d 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.

skills/blockchain/blockchain-security/SKILL.md · 545 lines

How it starts

The opening of the file, as written. The whole thing — 545 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Blockchain Security

Purpose

Guide blockchain-specific security analysis covering smart contract auditing, DeFi threat modeling, economic security, incident response, formal verification, and bug bounty programs. Combines traditional security engineering with blockchain-specific risks like economic attack vectors, flash loans, oracle manipulation, and MEV.

Agent Protocol

Trigger

"blockchain security", "smart contract audit", "DeFi security", "DeFi threat model", "blockchain threat modeling", "audit methodology", "blockchain incident response", "emergency pause", "fork coordination", "bug bounty", "Immunefi", "Code4rena", "economic security", "game theory blockchain", "incentive analysis", "MEV security", "certora", "formal verification blockchain", "Halmos", "Scribble", "solidity security", "smart contract vulnerability", "blockchain exploit", "flash loan attack", "oracle manipulation", "reentrancy", "access control blockchain", "cross-chain security", "bridge security"

Input Context

  • Smart contracts or protocol to analyze
  • Platform (EVM/Solana/Cosmos/Cardano)
  • Security objective (audit/threat model/incident response/pre-audit review)
  • Codebase location and audit history
  • Previous incidents or vulnerabilities
  • TVL and risk exposure

Output Artifact

Security analysis including: threat model, vulnerability findings, economic analysis, verification approach, and remediation recommendations.

Response Format

  1. Threat model: assets, actors, attack vectors, trust assumptions, attack surface
  2. Audit approach: methodology, tools, timeline, expected coverage
  3. Economic analysis: incentive structures, game theory, exploit scenarios
  4. Security controls: mitigations, circuit breakers, monitoring
  5. Verification: formal properties, invariants, proof techniques
  6. Incident response: emergency plan, communication template

Completion Criteria

  • Threat model identifies all trust assumptions and attack surfaces
  • Vulnerability findings include severity, impact, likelihood, and remediation
  • Economic analysis models incentive alignment and identifies exploit paths
  • Formal verification specifies key invariants (solvency, access control, correctness)
  • Emergency response plan covers: pause, communication, fork coordination, post-mortem

Read the full file on GitHub · 545 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. 4d ago First seen · 545 lines · 203 tokens per session scan A c2a4c9956f71

Subscribe to this mod's changes

blockchain-security is a skill published in the GitHub repository j4flmao/agent-skills (22 stars, last pushed yesterday), licensed MIT. It adds 203 tokens to every session and 5,325 once invoked, about $0.0010 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 2026-09-03.

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