Connect Claude to BigQuery

SaturnSQL's hosted MCP server gives Claude tools to browse your BigQuery project's schema, run read-only queries, and save results, without you managing a service account key locally.

Setup

1. Add your BigQuery connection in SaturnSQL: your project ID and a service account JSON key. Give the service account only the BigQuery Data Viewer and Job User IAM roles. See setting up a read-only BigQuery service account. The key is encrypted at rest and shown to you exactly once.

2. Click your name in the sidebar, then Install MCP, and paste the copied prompt into Claude. It connects itself, no local BigQuery MCP server or credential file to manage.

From there Claude can list datasets and tables, read INFORMATION_SCHEMA, and run SQL against your project, scoped to the same read-only, row-limited execution SaturnSQL uses everywhere else.

Why not a self-hosted BigQuery MCP server?

Self-hosted options exist, but they mean putting a service account key on your own machine or server and no shared query library. SaturnSQL's connector reuses a connection you've already secured, and every query Claude saves lands in the same library your team already uses.

Common questions

Can Claude run expensive queries by accident? The service account should carry only Data Viewer and Job User, and execution is row-limited the same way the editor is. For tighter control, set a custom query cost cap on the service account's project in GCP.

Can I limit Claude to specific datasets? Scope the service account's IAM roles to specific datasets instead of project-wide. See the BigQuery setup guide.

Is this free? Yes, MCP access is included on every plan, including Free. BigQuery is one of the database engines available from the Starter plan up.