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

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What you’ll need

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

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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;

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Step 2: Add the connection to QueryBear

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

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Step 3: Add QueryBear to Codex

~/.codex/config.toml: 
[mcp_servers.querybear]
type = "http"
url = "https://mcp.querybear.com/mcp"
Restart the Codex CLI.

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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.”

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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.

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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.