mysql-mcp-server: Instructions file for Claude Code

CLAUDE.md

mysql-mcp-server CLAUDE.md is an instructions file for Claude Code from eltonf/mysql-mcp-server. It costs 321 tokens per session, scanned A, original, MIT.

A set of Claude Code instructions for developing a MySQL server that inspects schemas and permits guarded read-only queries. Claude Code is a coding agent that follows repository instruction files.

In plain words
What is it for?
Use it when modifying, building, or testing the eltonf/mysql-mcp-server repository.
Why use it?
It gives contributors the repository's architecture, design decisions, and development commands in one place.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions CLAUDE.md.

This is eltonf/mysql-mcp-server's own configuration. It tells Claude Code how to work on mysql-mcp-server itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything mysql-mcp-server configures →

Reuse

Borrowing it

Nothing to install: this file belongs to eltonf/mysql-mcp-server. 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/eltonf/mysql-mcp-server/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/eltonf/mysql-mcp-server

Made for: Claude Code.

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Per session 321 This file is loaded in full into every session.
When invoked 321 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00321 $0.00321
Opus 5.5 $0.00128 $0.00128
Sonnet 5.5 $0.00064 $0.00064
Haiku 4.5 $0.00032 $0.00032

Measured 2mo ago against content hash 0f26eae0aaa8, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mysql-mcp-server 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 2mo 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 · 38 lines

What it actually says

CLAUDE.md

This repository is mysql-mcp-server, a MySQL-specific MCP server for schema introspection and guarded read-only queries.

Architecture

  • src/index.ts registers MCP tools and starts the stdio server.
  • src/core/* contains reusable code intended for future extraction:
    • config, logging, cache, MCP response helpers
    • schema metadata types
    • read-only query safety and LIMIT enforcement
    • SQL parsing and access-control validation
  • src/mysql/* contains MySQL-specific code:
    • mysql2 connection pool
    • identifier helpers
    • information_schema catalog queries
  • src/handlers/* adapts MCP tool input/output to the MySQL implementation.

Design Notes

  • One MCP server instance connects to one configured MySQL database (DB_NAME).
  • Tool database and schema inputs are compatibility fields and must match DB_NAME when provided.
  • MySQL catalog metadata comes from information_schema.
  • execute_query accepts read-only SELECT/WITH queries, validates access control, and enforces LIMIT.
  • Routine/function definition tools are intentionally deferred for v1.

Development Commands

npm run build
npm test
npm start

Example Domain

Use neutral examples such as app_db, customers, orders, products, and order_items. Do not add company-specific databases, internal hostnames, personal usernames, or private schema names to public docs or tests.

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.

  1. 2mo ago First seen · 38 lines · 321 tokens per session scan A 0f26eae0aaa8

Subscribe to this mod's changes

mysql-mcp-server CLAUDE.md is an instructions file published in the GitHub repository eltonf/mysql-mcp-server (0 stars, last pushed 6mo ago), licensed MIT. It adds 321 tokens to every session, about $0.0013 per session on Opus 5.5. 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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