mcp-safe-db

🛡️ mcp-safe-db

Zero-risk, strictly read-only SQL database inspector for AI agents (Claude Desktop, Antigravity, Cursor, Cline).

Let your AI explore schemas, inspect tables, and run SELECT queries without risking accidental DROP, UPDATE, or DELETE.

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⚡ The Problem

Giving an AI assistant database access is risky:

• A hallucinated UPDATE query without a WHERE clause can wipe production or local dev data.
• Semicolon injection (SELECT 1; DROP TABLE users;) can execute hidden destructive actions.
• Unbounded queries (SELECT *) blow up context windows and burn API tokens.

mcp-safe-db solves this with an unbreakable Triple-Layer Defense:

1. Layer 1 (Parser Guard): Strict regex validation blocks mutation keywords (INSERT, UPDATE, DROP, ALTER, PRAGMA, ATTACH, LOAD_EXTENSION), multiple statements, and comment bypasses. High limits are capped to 50 rows automatically.
2. Layer 2 (Connection Lock): SQLite connection is locked with PRAGMA query_only = ON;.
3. Layer 3 (OS / C-Engine Lock): Database is opened natively with { readOnly: true }. Even if raw SQL bypassed earlier checks, the underlying file handle physically forbids disk writes (attempt to write a readonly database).

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🚀 Quickstart

Direct execution via npx

npx mcp-safe-db ./path/to/database.sqlite

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🛠️ Configuration

1. Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "safe-db": {
      "command": "npx",
      "args": ["-y", "mcp-safe-db", "/absolute/path/to/your/database.sqlite"]
    }
  }
}

2. Antigravity IDE / Cursor / Cline

Add to your mcp_config.json:

{
  "mcpServers": {
    "safe-db": {
      "command": "npx",
      "args": ["-y", "mcp-safe-db", "/absolute/path/to/your/database.sqlite"]
    }
  }
}

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🧰 Available Tools for AI

Tool	Description	Safe Guard
list_tables	Lists all user tables and views	Filters out internal SQLite tables
describe_table	Inspects columns, data types, and primary keys	Sanitized table name validation
sample_table	Returns the first 3 rows of any table	Hard-capped to max 10 rows
safe_query	Executes arbitrary SELECT queries	Rejects mutations, auto-caps LIMIT

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🧪 Testing

npm test

Runs the automated security and safety tests.

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📄 License

MIT © 2026

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Vibe Coded with 💖 by MrSkele & Antigravity