Do I need to write a custom MCP server?

No. Google publishes a prebuilt toolbox binary that exposes BigQuery to MCP clients. You just download it and point Claude Code at it.

Do I need sudo to install the toolbox?

No. Everything goes into your home directory and Claude Code runs the toolbox as you. If a step prompts for sudo, the install path is wrong.

How does Claude Code authenticate to BigQuery?

Through Application Default Credentials. Run gcloud auth application-default login once and the toolbox picks up the same credentials your other Google Cloud tools use.

Tooling

Connect Claude Code to BigQuery in 2 steps with MCP

Wire Claude Code into BigQuery with Google's prebuilt MCP toolbox in two steps — list datasets, inspect schemas, and run SQL from any session.

April 18, 2026·Updated May 9, 2026·3 min read·Koppelvlak

You can connect Claude Code to BigQuery using Google’s prebuilt MCP toolbox. Once set up, Claude Code can list tables, inspect schemas and run SQL queries. You do not need to write a custom server.

What you’ll achieve

Claude Code can list datasets, inspect table schemas, and run SQL against your BigQuery project from any session.
No custom MCP server code — you point Claude at Google’s prebuilt toolbox binary.

Tutorial setup 3 prerequisites · 3 values

Requirements

Claude Code — installed and working from your terminal.
A Google Cloud project — with the BigQuery API enabled.
Application Default Credentials —
sign in once with gcloud auth application-default login. Install gcloud on Mac if you have not done this yet.

Your values

BIGQUERY_PROJECT_ID Your BigQuery project ID

Step-by-step guide

Step 1: Install the toolbox

Download the binary to your home directory and make it executable:

mkdir -p ~/.mcp && cd ~/.mcp \
  && curl -O https://storage.googleapis.com/genai-toolbox/v1.1.0/darwin/arm64/toolbox \
  && chmod +x toolbox

Step 2: Register the MCP server

Run this command — your project ID from the box above is already substituted in:

claude mcp add bigquery \
  --scope user \
  -e BIGQUERY_PROJECT={{BIGQUERY_PROJECT_ID}} \
  -- ~/.mcp/toolbox --prebuilt bigquery --stdio

The -- separates Claude Code’s flags from the toolbox’s own arguments. Your shell expands ~ to a full path before Claude Code sees it.

Verification / Testing

Restart Claude Code and ask it something like “list the tables in dataset X” or “show me the schema for orders”. You should see tool calls to the BigQuery server in the transcript, with results coming back from your project.

If nothing shows up, run claude mcp list in a fresh terminal to confirm the bigquery server is registered under your user scope.

What you learned

How MCP servers register at user scope so they’re available in every Claude Code session.
How to point Claude Code at Google’s prebuilt BigQuery toolbox without writing custom server code.

#claude-code #mcp #bigquery

Tooling