web3-solidity-audit-mcp

web3-solidity-audit-mcp is a skill for Claude Code, Codex from Awarexone/web3-bug-bounty-hunting-ai-skills. It costs 68 tokens per session (3,251 once invoked), scanned B, original, MIT.

An MCP server that combines several Solidity smart-contract analysis tools, including Slither, Aderyn, SWC weakness checks, and gas analysis. Solidity is the programming language commonly used for Ethereum smart contracts; MCP lets an AI coding tool call external tools.

In plain words
What is it for?
Use it to inspect Solidity contracts, look for known smart-contract weaknesses, apply DeFi and Web3 checks, review gas issues, and prepare CI checks.
Why use it?
It brings different contract scanners into one audit workflow and merges their findings into a severity-ordered report, reducing the need to run and compare tools separately.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: reads .claude/ paths; mentions Claude Code.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is solidity-audit-cli audit ./contracts/Token.sol.

Good fit Use it to inspect Solidity contracts, look for known smart-contract weaknesses, apply DeFi and Web3 checks, review gas issues, and prepare CI checks.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/Awarexone/web3-bug-bounty-hunting-ai-skills
agentmods
npx agentmods add skills/awarexone/web3-bug-bounty-hunting-ai-skills/web3-solidity-audit-mcp

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 web3-solidity-audit-mcp

README.md
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Your own site
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Your own site · 80×15
<a href="https://agentmods.dev/skills/awarexone/web3-bug-bounty-hunting-ai-skills/web3-solidity-audit-mcp"><img src="https://agentmods.dev/badge/skills/awarexone/web3-bug-bounty-hunting-ai-skills/web3-solidity-audit-mcp.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 68 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,251 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 3 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 8 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Supply Chain · line 38
    Remote code is downloaded and executed. This bypasses code review and could introduce malicious code.
    Fix: Avoid downloading and executing remote scripts. Use trusted packages from PyPI/npm. If remote fetch is required, verify checksums and use HTTPS.
  • high Tool Misuse · line 42
    Tool calls are chained to bypass individual safety checks or escalate capabilities beyond what any single tool call would allow.
    Fix: Limit tool chaining depth and validate the output of each tool before passing it to the next. Require explicit user approval for multi-step chains.
  • high Agent Snooping · line 53
    Skill accesses MCP server configuration files (mcp.json). MCP configs contain server URLs, authentication tokens, and tool definitions — reading them allows the skill to discover and potentially abuse other tool integrations.
    Fix: Remove all code or instructions that read MCP configuration files (mcp.json). MCP server details should be managed by the agent runtime, not read by individual skills.
  • medium MCP Rug Pull · line 46
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 79
    Docker image references without a specific tag (:latest is implicit) or digest (@sha256:...) can be silently replaced by a malicious image.
    Fix: Pin the image: image:tag or image@sha256:abc123
  • medium Data Exfiltration · line 286
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Privilege Escalation · line 288
    Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
    Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
  • low Supply Chain · line 42
    Remote code is downloaded and executed. This bypasses code review and could introduce malicious code.
    Fix: Avoid downloading and executing remote scripts. Use trusted packages from PyPI/npm. If remote fetch is required, verify checksums and use HTTPS.
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 $0.00068 $0.03251
Opus 5 $0.00034 $0.01625
Sonnet 5 $0.00014 $0.00650
Haiku 4.5 $0.00007 $0.00325

Measured 12d ago against content hash c83469306520, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade B, and why

web3-solidity-audit-mcp scanned grade B with 3 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 12d 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.

Asks for rootlowPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

sudo install -m 755 /tmp/aderyn /usr/local/bin/aderyn

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Downloads and executes remote codemediumSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

curl -L https://foundry.paradigm.xyz | bash && foundryup

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -L https://foundry.paradigm.xyz | bash && foundryup
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

web3-solidity-audit-mcp/SKILL.md · 399 lines

How it starts

The opening of the file, as written. The whole thing — 399 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SKILL 36 — SOLIDITY AUDIT MCP: CLAUDE-NATIVE SMART CONTRACT SCANNER

From: github.com/mariano-aguero/solidity-audit-mcp — MCP server plugging Slither + Aderyn + SWC patterns into Claude Code 10 tools. 19 built-in finding explainers. 86 SWC detectors. DeFi + Web3 preset detector packs. CI/CD ready.


WHAT IT IS

An MCP server that gives Claude Code direct access to Slither, Aderyn, Slang AST, SWC pattern matching, and a gas optimizer — all in one unified pipeline with auto-deduplication. Instead of context-switching between tools, you ask Claude to audit a contract and get a merged, severity-sorted report.

Stack:

External (install separately):
  Slither   → Trail of Bits, 90+ detectors, deep data flow
  Aderyn    → Cyfrin Rust-based, fast AST analysis
  Echidna   → Property fuzzer (optional)
  Halmos    → Symbolic execution (optional)

Built-in (no install):
  Slang     → Nomic Foundation AST parser, precise pattern matching
  SWC       → 86 detectors against Smart Contract Weakness Classification registry
  Gas       → Storage packing, loop, calldata optimizations

INSTALL & CONFIGURE

# Prerequisites
pip install slither-analyzer solc-select
solc-select install 0.8.20 && solc-select use 0.8.20
curl -L https://foundry.paradigm.xyz | bash && foundryup

# Aderyn (Rust)
cargo install aderyn
# or: curl -L https://raw.githubusercontent.com/Cyfrin/aderyn/dev/cyfrinup/install | bash

# MCP server
npm install -g solidity-audit-mcp
# or: npx solidity-audit-mcp

# Optional fuzzers
brew install echidna    # macOS
pip install halmos      # symbolic execution

Wire into Claude Code — add to ~/.claude/mcp.json:

{
  "mcpServers": {
    "audit": {
      "command": "npx",
      "args": ["solidity-audit-mcp"]
    }
  }
}

Or project-level .mcp.json in repo root:

{
  "mcpServers": {
    "audit": {
      "command": "node",
      "args": ["/path/to/solidity-audit-mcp/dist/index.js"]
    }
  }
}

Docker (all tools pre-installed):

docker run -v $(pwd):/contracts solidity-audit-mcp audit /contracts/Token.sol

Read the full file on GitHub · 399 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. 12d ago First seen · 399 lines · 68 tokens per session scan B c83469306520

Subscribe to this mod's changes

web3-solidity-audit-mcp is a skill published in the GitHub repository Awarexone/web3-bug-bounty-hunting-ai-skills (143 stars, last pushed 18d ago), licensed MIT. It adds 68 tokens to every session and 3,251 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it B with 3 findings (asks for root, downloads and executes remote code, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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