mysql_query
Run SQL queries against MySQL database (READ-ONLY)
LABSCO SUMMARY
Questions get answered from the database, and what it may change is a decision you make once.
Instead of pasting a table into the conversation, the model writes the query and reads the rows back. Writes are not a single on switch — insert, update, delete and DDL are separate flags, and they can be set per database, so a development schema can be writable while production stays read-only on the same connection.
What it is
A MySQL server with one tool and one resource: mysql_query runs SQL, and mysql://tables lists the tables and their column metadata. Everything else is configuration — what it may write, which databases it can reach, how the connection is secured, and what gets masked on the way out.
What you get
- SQL run against the configured MySQL database, returning rows (
mysql_query) - Tables and their column metadata listed as a resource, so a schema question does not need a query (
mysql://tables) - Read-only by default:
ALLOW_INSERT_OPERATION,ALLOW_UPDATE_OPERATION,ALLOW_DELETE_OPERATIONandALLOW_DDL_OPERATIONeach turn on one class of write and nothing else - Per-database overrides on all four, so development can write while production stays readable — and a multi-DB mode that queries across databases without reconnecting, with writes off across all of them by default
- PII redaction that masks sensitive columns in results, with extra column names and regex patterns you supply, and
SELECT *refused while it is on unless you allow it - Guardrails on cost as well as risk:
MYSQL_RATE_LIMITat 100 queries a minute,MYSQL_MAX_QUERY_COMPLEXITY, a 30000 ms query timeout and a 10-connection pool, all adjustable - SSL and TLS with an mTLS option, a Unix socket path instead of host and port, a connection string for rotating credentials, an SSH tunnel for remote databases, and a remote HTTP mode behind a bearer token
Requirements
Node.js v20 or newer, MySQL 5.7 or newer with 8.0 recommended, and a MySQL user with the privileges you intend to use. npx @benborla29/mcp-server-mysql with MYSQL_HOST, MYSQL_PORT, MYSQL_USER, MYSQL_PASS and MYSQL_DB set — omit MYSQL_DB for multi-DB mode. Every write class is off until you turn it on, and the read-only transaction enforcement behind them has its own disable flag that is worth leaving alone. Grant the database user only what the flags allow, so the two limits agree.
Setup effort
One command plus credentials — npm install -g @benborla29/mcp-server-mysql, then supply credentials
USE CASES
01
Answering a question from live data
Have the model write the SQL and read the rows. No export, no pasted table, and no stale copy of a number that changed this morning.
02
Checking what the schema actually contains
Read the tables resource rather than querying information_schema by hand. Column metadata comes with it, which is usually the half of the answer you were about to ask for next.
03
Letting an agent write to development but not production
Set the schema-specific permission lists so insert and update are allowed on development and denied on production. One connection, two risk profiles, decided in configuration rather than in the prompt.
04
Querying a database with real customer data in it
Turn on PII redaction so sensitive columns are masked before results reach the model, and add your own column names and patterns for the fields it would not guess. SELECT * is refused while redaction is on unless you allow it, which is the point.
05
Reaching a database that is not on your machine
Use the built-in SSH tunnel, or SSL with client certificates for mTLS. The remote HTTP mode behind a bearer token covers the case where the server itself is not local either.
06
Keeping a runaway query from hurting
The rate limit, the complexity ceiling and the query timeout are all set before anything runs. A model that writes an expensive join is a normal event, not an incident.
1 tool
Counted once with only startup setup. Other versions, modes or optional credentials may expose a different list.
BEFORE YOU INSTALL
What to know first
Tools you get
1 tool when we connected. All write operations are disabled by default; INSERT, UPDATE, DELETE and DDL each need their own flag, with per-database overrides. Schema browsing is an MCP resource, mysql://tables, not a tool.
Requires
- npx on PATH
- Node.js v20 or later
- MySQL 5.7+
- MYSQL_USER in your environment
- MYSQL_PASS in your environment
CONTEXT COST
Light Standing cost
Rated by the size of the one tool definition that rides along on every turn
INSTALLATION
Connect your client
Server setup
TERMINAL
npm install -g @benborla29/mcp-server-mysqlMCP Clients
Claude Code
CLAUDE CODE · TERMINAL
claude mcp add mcp_server_mysql -e MYSQL_HOST="127.0.0.1" -e MYSQL_PORT="3306" -e MYSQL_USER="root" -e MYSQL_PASS="<YOUR_MYSQL_PASS>" -e MYSQL_DB="<YOUR_MYSQL_DB>" -- npx @benborla29/mcp-server-mysqlClaude Desktop
CLAUDE DESKTOP · JSON
{
"mcpServers": {
"mcp_server_mysql": {
"command": "npx",
"args": [
"-y",
"@benborla29/mcp-server-mysql"
],
"env": {
"MYSQL_HOST": "127.0.0.1",
"MYSQL_PORT": "3306",
"MYSQL_USER": "root",
"MYSQL_PASS": "<YOUR_MYSQL_PASS>",
"MYSQL_DB": "<YOUR_MYSQL_DB>"
}
}
}
}Codex
CODEX · TERMINAL
codex mcp add mcp_server_mysql --env MYSQL_HOST="127.0.0.1" --env MYSQL_PORT="3306" --env MYSQL_USER="root" --env MYSQL_PASS="<YOUR_MYSQL_PASS>" --env MYSQL_DB="<YOUR_MYSQL_DB>" -- npx -y @benborla29/mcp-server-mysqlAny MCP client — self-hosted HTTP
Create a .env file and copy from the example at https://github.com/benborla/mcp-server-mysql/blob/main/.env
Set your MySQL credentials, IS_REMOTE_MCP=true, REMOTE_SECRET_KEY to a secure string, and optionally PORT (default: 3000)
Load and run:
ANY MCP CLIENT — SELF-HOSTED HTTP · TERMINAL
source .env
npx @benborla29/mcp-server-mysqlConfigure your agent — <YOUR_HOST> is the machine running the server, and the Bearer value is your REMOTE_SECRET_KEY:
ANY MCP CLIENT — SELF-HOSTED HTTP · JSON
{
"mcpServers": {
"mysql": {
"url": "http://<YOUR_HOST>:3000/mcp",
"type": "http",
"headers": {
"Authorization": "Bearer <YOUR_REMOTE_SECRET_KEY>"
}
}
}
}"type": "http" is how Claude Code and VS Code name this transport; Cline and Roo Code spell it "streamableHttp" (as the project's docs do), and Cursor reads the url without a type.
