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Contract Security Scanner

Official registry Security

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

Source code Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

NPM package @fino314-oss/contract-scanner-mcp
Claude Code 
claude mcp add contract-security-scanner -e 'BASESCAN_API_KEY=<your basescan_api_key>' -- npx -y @fino314-oss/contract-scanner-mcp@1.0.0
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "contract-security-scanner": {
            "command": "npx",
            "args": [
                "-y",
                "@fino314-oss/contract-scanner-mcp@1.0.0"
            ],
            "env": {
                "BASESCAN_API_KEY": "<your basescan_api_key>"
            }
        }
    }
}

Environment variables

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

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. Contract Security Scanner — MCP Server
  2. Installation
  3. Usage examples
  4. What gets analyzed
  5. Risk scoring
  6. Technical notes

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:

{
  "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):

{
  "mcpServers": {
    "contract-scanner": {
      "command": "node",
      "args": ["/Users/sam/Desktop/samDev/p8/mcp/server.js"]
    }
  }
}
Cline (VS Code extension)
  1. Open Cline settings → MCP Servers → Add server
  2. Set type: stdio
  3. Command: node /Users/sam/Desktop/samDev/p8/mcp/server.js
Any MCP client (generic)

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

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

Usage examples

Once connected, just ask your AI assistant naturally:

"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

CheckSource
Source code verified?BaseScan API
Mint / burn functionsBytecode selector scan
Pause / freezeBytecode selector scan
Blacklist / whitelistBytecode selector scan
Backdoors (rescueTokens, withdrawAll)Bytecode selector scan
Upgradeable proxyBaseScan + delegatecall detection
Contract ageBaseScan transaction history
Activity levelBaseScan recent txs

Risk scoring

ScoreLabelMeaning
0-9SAFENo red flags
10-29LOWMinor concerns
30-49MEDIUMElevated risk — review before interacting
50-69HIGHSignificant risk — small amounts only
70+CRITICALAvoid — 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

Frequently asked questions

What is Contract Security Scanner?

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

How do I install Contract Security Scanner?

It runs on your machine. In Claude Code: claude mcp add contract-security-scanner -e 'BASESCAN_API_KEY=<your basescan_api_key>' -- npx -y @fino314-oss/contract-scanner-mcp@1.0.0. For other clients, paste the JSON configuration from this page into their MCP settings.

Does Contract Security Scanner need an API key?

Yes. It expects BASESCAN_API_KEY, which you set in its configuration.

Is Contract Security Scanner open source?

Its code is public on GitHub, but the repository does not declare a standard license.

Who maintains Contract Security Scanner?

It is published by fino-oss. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.