Codesafer

CodeSafer (cleaner-code)

AI code security scanner as a Model Context Protocol (MCP) server.

Detects hidden threats in AI-generated code that traditional linters miss.

Website: codesafer.org · MCP Clients: Claude Code, Cursor, VS Code + Copilot, Cline

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Why CodeSafer?

AI coding assistants generate code fast — but who's checking it for hidden threats?

Recent supply-chain attacks show that malicious code can hide in ways human reviewers and traditional linters routinely miss:

• Invisible Unicode characters injected into identifiers (30+ variants)
• BiDi / Trojan Source attacks that reorder how code is displayed vs. executed (CVE-2021-42574)
• Homoglyphs — Cyrillic characters masquerading as Latin (CVE-2021-42694)
• Glassworm-style Unicode steganography hiding payloads in whitespace
• Rules file backdoors planted in .cursorrules, CLAUDE.md, and other AI config files
• Typosquatted dependencies in package.json
• Obfuscation patterns — eval + base64, reverse shells, packed payloads

CodeSafer scans for all of these before the code runs on your machine.

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How it works

CodeSafer runs as a local MCP server. Your AI client (Claude Code, Cursor, etc.) calls its tools when reviewing or generating code, and findings are returned inline.

Hybrid detection:

1. 8 static analysis scanners — deterministic rules for known attack categories (fast, zero false-negatives on the patterns they cover).
2. CodeBERT deep analysis — transformer model classifies code chunks as malicious/benign with confidence scores. Catches obfuscated or novel patterns that static rules miss.

Nothing leaves your machine. The AI analysis runs locally against a tokenizer server.

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Features

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MCP Tools

CodeSafer exposes six tools to your MCP client:

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Installation

Prerequisites

• Node.js 18 or later
• An MCP-compatible client (Claude Code, Cursor, VS Code + Copilot, Cline)

From source

git clone https://github.com/goldmembrane/cleaner-code.git

cd cleaner-code npm install npm run build

Configure your MCP client

Claude Code (~/.claude.json or project .mcp.json):

{

"mcpServers": { "codesafer": { "command": "node", "args": ["/absolute/path/to/cleaner-code/dist/index.js"] } } }

Cursor (.cursor/mcp.json):

{

"mcpServers": { "codesafer": { "command": "node", "args": ["/absolute/path/to/cleaner-code/dist/index.js"] } } }

Restart your client, and CodeSafer tools will appear in the tool picker.

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Usage

Once configured, ask your AI client things like:

• *"Scan this file for hidden security issues."*
• *"Check the dependencies in package.json for typosquatting."*
• *"Scan .cursorrules for a rules-file backdoor."*
• *"Run a deep AI analysis of src/auth.ts."*
• *"Explain what a Trojan Source attack is and how to fix the finding above."*

The client will call the appropriate MCP tool and return findings with severity, line numbers, and remediation guidance.

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Free tier & Plans

CodeSafer is free to use. Static analysis (scan_file, scan_directory, scan_rules_file, check_dependencies, explain_finding) has no limits.

AI deep analysis (ai_analyze) includes 10 free runs per session. Paid plans for higher AI quotas are available at codesafer.org.

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Detection categories

CodeSafer detects threats across 9 categories:

1. Invisible Unicode characters — 30+ variants including Zero-Width Space, Zero-Width Joiner
2. BiDi / Trojan Source attacks — CVE-2021-42574
3. Homoglyphs — Cyrillic/Greek characters masquerading as Latin (CVE-2021-42694)
4. Unicode steganography — Glassworm patterns in whitespace
5. Rules file backdoors — malicious instructions in .cursorrules, CLAUDE.md, etc.
6. Dependency risks — typosquatting and suspicious install scripts
7. Obfuscation patterns — eval + base64, packed payloads, reverse shells
8. Static analysis findings — 8 deterministic scanners
9. AI deep analysis — CodeBERT transformer for novel and obfuscated threats

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Project structure

cleaner-code/

├── src/ │ ├── index.ts # MCP server entry point │ ├── api-server.ts # Optional HTTP API server │ ├── types.ts # Scanner interfaces │ ├── utils.ts # File collection, summary formatting │ └── scanner/ │ ├── invisible.ts # Invisible Unicode scanner │ ├── bidi.ts # BiDi / Trojan Source scanner │ ├── homoglyph.ts # Homoglyph scanner │ ├── encoding.ts # Encoding / charset scanner │ ├── obfuscation.ts # Obfuscation pattern scanner │ ├── steganography.ts # Unicode steganography scanner │ ├── rules-backdoor.ts # Rules file backdoor scanner │ ├── dependency.ts # Dependency risk scanner │ └── ai-analyzer.ts # CodeBERT deep analyzer ├── ml/ # ML model assets and tokenizer ├── functions/ # Cloud function deployments ├── deploy/ # Deployment manifests └── web/ # Landing page assets

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License

ISC — see the LICENSE file for details.

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Links

• Website: codesafer.org
• Model Context Protocol: modelcontextprotocol.io
• Report issues: GitHub Issues