MySQL + Codex - QueryBear

This guide walks through connecting MySQL (or MariaDB) to Codex (OpenAI’s terminal coding agent) using QueryBear’s managed MCP server.

What you’ll need

A QueryBear account (sign up free)
A MySQL or MariaDB database (5.7+ / 10.x+)
Codex CLI installed

Step 1: Create a read-only MySQL user

CREATE USER 'querybear'@'%' IDENTIFIED BY 'choose-a-strong-one';
GRANT SELECT ON your_db.* TO 'querybear'@'%';
GRANT SHOW VIEW ON your_db.* TO 'querybear'@'%';
FLUSH PRIVILEGES;

Step 2: Add the connection to QueryBear

Dashboard → Connections → New connection → MySQL, with the credentials from Step 1.

Step 3: Add QueryBear to Codex

~/.codex/config.toml:

[mcp_servers.querybear]
type = "http"
url = "https://mcp.querybear.com/mcp"

Restart the Codex CLI.

Step 4: Authorize and verify

Start a Codex session. First tool call opens OAuth in browser.

“What QueryBear tools do you have? List my connections.”

Try it

“In our MySQL DB, find the orders that had a refund processed in the last 7 days. Include order id, customer, refund amount, and reason.”

Codex calls get_schema, joins orders and refunds, and returns the result.

MySQL + Codex gotchas

TOML typos silently disable the server. If querybear doesn’t appear in the tool list, re-check the TOML block.
Restart Codex CLI fully after editing config — it caches MCP discovery on startup.
Multi-statement and stored procedure calls are blocked. Allow-list specific procedures per connection if needed.
Name the connection in your prompt (“using the prod connection…”) to skip list_connections.

MySQL MCP server — MySQL-specific deep dive
Codex client — Codex overview
Security model — what the gateway protects against

​What you’ll need

​Step 1: Create a read-only MySQL user

​Step 2: Add the connection to QueryBear

​Step 3: Add QueryBear to Codex

​Step 4: Authorize and verify

​Try it

​MySQL + Codex gotchas

​Related