io.github.fino-oss/contract-scanner

Official

by fino-oss · JavaScript

Contract Security Scanner

Scans Base L2 smart contracts for security risks. Risk score 0-100, detects backdoors & proxies.

Analyze smart contracts for security vulnerabilities and backdoors.

README.md3 KBView on GitHub

Contract Security Scanner — MCP Server

Scan any Base L2 smart contract for security risks directly from your AI assistant.

3 tools exposed:

scan_contract — Full security scan (source verification, risky selectors, age, activity)
batch_scan — Compare up to 5 contracts side by side
interpret_risk — Get an actionable recommendation (SAFE / CAUTION / HIGH_RISK / DO_NOT_USE)

Risk score: 0-100. Analyzes: mint/blacklist/backdoor functions, proxy patterns, source verification, contract age, transaction activity.

Installation

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

json

{
  "mcpServers": {
    "contract-scanner": {
      "command": "node",
      "args": ["/Users/sam/Desktop/samDev/p8/mcp/server.js"]
    }
  }
}

Restart Claude Desktop. The tools appear automatically.

Cursor

Add to .cursor/mcp.json (project) or ~/.cursor/mcp.json (global):

json

{
  "mcpServers": {
    "contract-scanner": {
      "command": "node",
      "args": ["/Users/sam/Desktop/samDev/p8/mcp/server.js"]
    }
  }
}

Cline (VS Code extension)

Open Cline settings → MCP Servers → Add server
Set type: stdio
Command: node /Users/sam/Desktop/samDev/p8/mcp/server.js

Any MCP client (generic)

The server uses stdio transport — just pipe JSON-RPC messages:

bash

node /Users/sam/Desktop/samDev/p8/mcp/server.js

Usage examples

Once connected, just ask your AI assistant naturally:

code

"Scan this contract before I approve: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"

"Compare the risk of these 3 Aave clones: 0x... 0x... 0x..."

"Is this token safe to buy? 0x4ed4e862860bed51a9570b96d89af5e1b0efefed"

What gets analyzed

Check	Source
Source code verified?	BaseScan API
Mint / burn functions	Bytecode selector scan
Pause / freeze	Bytecode selector scan
Blacklist / whitelist	Bytecode selector scan
Backdoors (rescueTokens, withdrawAll)	Bytecode selector scan
Upgradeable proxy	BaseScan + delegatecall detection
Contract age	BaseScan transaction history
Activity level	BaseScan recent txs

Risk scoring

Score	Label	Meaning
0-9	SAFE	No red flags
10-29	LOW	Minor concerns
30-49	MEDIUM	Elevated risk — review before interacting
50-69	HIGH	Significant risk — small amounts only
70+	CRITICAL	Avoid — potential rug or backdoor

Technical notes

Chain: Base L2 only (https://mainnet.base.org)
API: BaseScan free tier (no key needed for basic checks; set BASESCAN_API_KEY env var for full source analysis)
No wallet needed: read-only RPC calls only
Latency: ~2-5s per contract (network dependent)

Built on Base. Agent wallet: 0x804dd2cE4aA3296831c880139040e4326df13c6e

Install

Configuration

Environment variables

BASESCAN_API_KEYsecret

BaseScan API key for source code analysis (optional — basic bytecode scan works without it)

claude_desktop_config.json

{
  "mcpServers": {
    "contract-scanner": {
      "command": "npx",
      "args": [
        "-y",
        "@fino314-oss/contract-scanner-mcp@1.0.0"
      ],
      "env": {
        "BASESCAN_API_KEY": "<YOUR_BASESCAN_API_KEY>"
      }
    }
  }
}