mysql-readonly

This MCP server provides secure, read-only access to a MySQL database. It exposes a set of MCP tools that let you inspect schemas, preview data, and run constrained queries without risking data modification. The recommended setup uses npx so you can launch it on-demand without local installation. To use it, configure an MCP client to point at the server entry (for example, the my-database entry shown in the configuration). The available tools include: list_tables to enumerate tables and metadata, describe_table to view column definitions and keys, preview_data to sample rows with optional filters, run_query to execute safe SELECT-like queries with strict validation, show_relations to explore foreign key relationships, and db_stats to get a snapshot of database size and table counts. Each tool enforces the read-only policy and query limits described in the documentation, making it suitable for AI-assisted exploration and analysis.

Prerequisites:

• Node.js and npm installed on your machine
• Access to install global npm packages if you plan to install the binary globally

Install steps:

1. Global installation (optional):

npm install -g mysql-readonly-mcp
mysql-readonly-mcp

2. If you prefer to use npx (no installation):

npx -y mysql-readonly-mcp

3. Run a local example (using the quick start configuration):

• Ensure you have a MySQL server reachable with the environment values you provide
• Start the MCP server with the configuration shown in the Quick Start example (or your own) to begin listening for MCP clients

Tips and considerations:

• The server enforces read-only actions. Attempts to modify data (INSERT, UPDATE, DELETE) or any schema changes (DROP, ALTER, CREATE, TRUNCATE) are blocked.
• Connection details are provided via environment variables (MYSQL_HOST, MYSQL_PORT, MYSQL_USER, MYSQL_PASSWORD, MYSQL_DATABASE). Do not expose sensitive credentials in logs.
• Query limits: previews are capped (default max 100 rows) and custom queries up to 5000 rows (timeout 30 seconds per query).
• For multi-database setups, create separate MCP entries with distinct MYSQL_HOST/PORT/DATABASE values.
• If you encounter connection issues, verify network access to MySQL, correct credentials, and that the user has appropriate privileges (SELECT/SHOW/DESCRIBE/EXPLAIN).