What is mysql-mcp CLAUDE.md?

Repository instructions for a read-only MySQL server that lets AI agents query one or more MySQL databases through MCP, a standard way for AI tools to use external services.

Installing dependencies, starting the server for testing, and understanding its database connections, multiple-server setup, and read-only checks.

They give the coding agent the project layout, setup commands, and safety rules it needs to work on the server without changing database data.

How saturnino-adrales/mysql-mcp configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to saturnino-adrales/mysql-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/saturnino-adrales/mysql-mcp/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/saturnino-adrales/mysql-mcp

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/saturnino-adrales/mysql-mcp/claude-md/github.svg)](https://agentmods.dev/instructions/saturnino-adrales/mysql-mcp/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/saturnino-adrales/mysql-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/saturnino-adrales/mysql-mcp/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/saturnino-adrales/mysql-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/saturnino-adrales/mysql-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 815 This file is loaded in full into every session.

When invoked 815 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00815	$0.00815
Opus 5	$0.00407	$0.00407
Sonnet 5	$0.00163	$0.00163
Haiku 4.5	$0.00081	$0.00081

Measured 10d ago against content hash 2b00f0b76ef7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

mysql-mcp CLAUDE.md scanned grade A with 0 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 10d 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 89 lines

How it starts

The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

MySQL MCP Server - A Model Context Protocol server providing readonly MySQL database operations for AI agents with support for multiple database servers. Built as an npm package that can be installed locally and integrated with Claude Desktop.

Development Commands

# Install dependencies
npm install

# Start the server (for testing)
npm start

# Run the server directly
node server.js

Architecture

Core Components

server.js - Main MCP server implementation

MySQLMCPServer class handles all database operations and MCP protocol
Uses StdioServerTransport for communication with Claude Desktop
Multi-server connection management via Map structures:
- this.servers - Stores server configurations loaded from environment
- this.connections - Stores active MySQL connections per server
Lazy connection pattern - connects to MySQL only when first tool is called
All database operations are wrapped with security checks to ensure readonly access

Multi-Server Architecture

loadServerConfigs() method (server.js:31-69) handles two configuration modes:
1. Multiple servers via MYSQL_SERVERS - JSON object with named server configurations
2. Single server via MYSQL_ vars* - Backward compatible, creates 'default' server
Each server maintains independent connection with its own database context
Server selection via optional server parameter in all tool calls (defaults to 'default')

Available MCP Tools

list_servers - Shows all configured MySQL servers and connection status
list_tables - Returns all tables in the database (accepts server param)
describe_table - Shows table structure with columns, types, keys (accepts server param)
query - Executes SELECT queries only (accepts server param)
show_databases - Lists all accessible databases (accepts server param)
use_database - Switches active database on a server (accepts server param)

Read the full file on GitHub · 89 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.

10d ago First seen · 89 lines · 815 tokens per session scan A 2b00f0b76ef7

Subscribe to this mod's changes

mysql-mcp CLAUDE.md is an instructions file published in the GitHub repository saturnino-adrales/mysql-mcp (0 stars, last pushed 1y ago), licensed MIT. It adds 815 tokens to every session, about $0.0041 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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