bqcheck

Know what a BigQuery query costs before you run it. Highlight SQL anywhere in Chrome, click the extension, see the bill.

Runs entirely on your machine via a small local server and a Chrome extension. Uses your existing gcloud creds.

Setup

You'll need Python 3.11+, uv, and gcloud signed in:

gcloud auth application-default login
gcloud auth login

Start the server:

cd server
uv sync
uv run bqcheck-server

Load the extension:

1. Open chrome://extensions and turn on Developer mode
2. Load unpacked → pick the extension/ folder
3. Pin it to the toolbar

Using it

Three ways to check a query:

• Popup : highlight SQL, click the icon. The selection drops into the editor — pick a project, hit Calculate Cost. You can also paste SQL directly.
• Right-click : select SQL → Check BQ cost. Result shows on the toolbar badge; the popup never opens.
• Keyboard : Cmd+Shift+, (mac) / Ctrl+Shift+, (Win/Linux) with SQL selected. Same badge-only flow as the right-click menu. Rebind at chrome://extensions/shortcuts.

Click the ⚙ to set your org's price per TiB (defaults to $6.25).

Also

There's a CLI if you want a one-off estimate from the terminal:

uv run bqcheck query.sql --project my-proj

Server flags: --port 7899 (also update manifest.json's host_permissions and the SERVER constant in extension/shared.js), --project my-proj for a default fallback.

When things break

• ERR on the badge : server isn't running.
• Empty project dropdown : gcloud auth login then hit ↻.
• 403 from BigQuery : your ADC user needs BigQuery Job User on that project.

License

MIT. See LICENSE.