MCP Toolbox for Databases in Claude Desktop ask your database questions in plain English.
Connect Google's MCP Toolbox for Databases to Claude Desktop and chat with your data through tools you define — not raw SQL. Exact claude_desktop_config.json entry for Mac and Windows, plus the restart and log dance.
MCP Toolbox for Databases (github.com/googleapis/genai-toolbox, 15.5k stars) is Google's MCP server for letting agents query databases safely. You describe your database sources and a set of named, parameterized tools in a tools.yaml file; the Toolbox serves only those tools. In Claude Desktop, that turns into a chat where 'how many orders shipped last week?' executes a query you wrote and approved in advance.
It's distributed as an OCI container image rather than an npm or pip package, so the setup below uses Docker. Claude Desktop launches it as a stdio subprocess via claude_desktop_config.json.
Prepare the pieces
You need three things: Docker running, a reachable database (the Toolbox supports engines including PostgreSQL, MySQL, SQL Server, BigQuery, and Spanner — the repo docs list them all), and a tools.yaml that names a source plus the tools Claude may call against it. Keep the first version read-only; you can add write tools once you've watched how Claude uses the read ones.
Edit claude_desktop_config.json
The config file lives at ~/Library/Application Support/Claude/claude_desktop_config.json on macOS and %APPDATA%\Claude\claude_desktop_config.json on Windows; the in-app path is Settings > Developer > Edit Config. Add the Toolbox under mcpServers. Use the absolute path to your tools.yaml in the volume mount — GUI launches don't expand ~ or shell variables reliably.
{
"mcpServers": {
"toolbox": {
"command": "docker",
"args": [
"run", "-i", "--rm",
"-v", "/Users/you/db/tools.yaml:/config/tools.yaml",
"us-central1-docker.pkg.dev/database-toolbox/toolbox/toolbox:latest",
"--tools-file", "/config/tools.yaml",
"--stdio"
]
}
}
}Restart fully, then verify
Claude Desktop only reads this file at launch, and closing the window is not quitting the app — use Cmd-Q on macOS or quit from the system tray on Windows, then reopen. The Toolbox's tools should appear under the tools icon in the chat input. Ask a question your tools.yaml can answer and confirm Claude proposes a Toolbox tool call; you'll approve it before it runs.
Troubleshooting in Claude Desktop
Server not listed after a real restart? Check the MCP logs: ~/Library/Logs/Claude/ on macOS (per-server mcp-server-toolbox.log files) or %APPDATA%\Claude\logs on Windows. Docker errors land there verbatim — image pull failures, a bad mount path, or 'docker: command not found.' That last one is a PATH problem: Claude Desktop doesn't inherit your shell PATH, so writing the absolute Docker binary path (e.g. /usr/local/bin/docker) into the command field is the reliable fix.
Two more recurring failures. Omitting -i from docker run kills the stdio handshake immediately. And databases on your host machine are not localhost from inside the container — point your tools.yaml at host.docker.internal instead. If tools appear but calls error, run the same docker command in a terminal: the Toolbox prints YAML validation and connection errors to stderr at startup.
The live listing
You can preview the Toolbox's probed tool surface on its Loomal marketplace listing at https://loomal.ai/marketplace/mcp-toolbox-for-databases before you commit to the setup. Maintainers of MCP servers can claim listings like this one to verify ownership and publish per-call pricing for agents.
FAQ
How do I install the Toolbox for Databases in Claude Desktop?
Add a docker run entry under mcpServers in claude_desktop_config.json that mounts your tools.yaml and passes --tools-file and --stdio, then fully quit and reopen Claude Desktop. The tools you defined appear in the chat's tool list once the server connects.
Where is Claude Desktop's config file?
On macOS: ~/Library/Application Support/Claude/claude_desktop_config.json. On Windows: %APPDATA%\Claude\claude_desktop_config.json. Settings > Developer > Edit Config opens it from inside the app on both platforms.
Why doesn't the Toolbox show up after I edited the config?
Either the app wasn't fully quit (the config is only read at launch), the JSON has a syntax error, or the docker command failed. The per-server logs in ~/Library/Logs/Claude (macOS) or %APPDATA%\Claude\logs (Windows) show the exact failure — PATH issues with the docker binary are the most common.
Can Claude run arbitrary SQL against my database?
No. The Toolbox only exposes the named tools you declare in tools.yaml, each mapped to a specific parameterized query. Claude also asks for your approval before each tool call in Desktop, so you see every query before it executes.
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