Cupola
A data analyst’s workbench, in a browser tab.
Cupola is a fast, modern SQL workbench powered by DuckDB — running entirely in your browser. Write SQL, pivot and chart the results, and hand the hard parts to a built-in AI analyst. Sign in with Google and start exploring live data in seconds.
No install. No account to create. Free and open source.
Catalog
- 🌋 volcanoes
- eruptions
- regions
- ƒ nearest()
SELECT name, country, primary_type
FROM volcanoes
ORDER BY last_eruption_year DESC
LIMIT 3;What is Cupola?
A modern shell for working with data
Think of Cupola as a data analyst’s command center that opens in any browser. Under the hood it runs Haybarn — Query.Farm’s distribution of DuckDB — compiled to multi-threaded WebAssembly. That means a real, fast analytical database runs inside the tab: your queries don’t wait on a server, and your data doesn’t have to leave your machine.
On top of that engine, Cupola adds the things analysts actually want — a polished SQL shell, pivot tables, charts and maps, a catalog browser, and a built-in AI analyst — and lets you connect to live data sources with a single sign-in.
New to VGI? You don’t need to be.
VGI is Query.Farm’s way of turning APIs, services, and databases into live SQL tables. Cupola speaks it natively, so a single URL connects you to a ready-to-query source — but you don’t have to learn VGI to start. Open a source, and it’s just tables and SQL.
What you can do
Everything an analyst needs, in one tab
A real database, in your browser
Cupola runs Haybarn — Query.Farm’s build of DuckDB — compiled to multi-threaded WebAssembly. Genuine analytical SQL runs locally in the tab, with no install and nothing to provision.
A shell built for analysts
A fast SQL terminal with autocomplete, history, dot commands, and sessions that survive a reload — plus formatted results and quick export to CSV or Excel.
An AI analyst on tap
A built-in assistant that writes and runs SQL, inspects your schema, and explains what it found in plain language. It does the tedious parts so you can ask the next question.
Pivot, chart, and map
Turn any result into an interactive pivot table, a chart, or a map for geospatial data — drag-and-drop, backed directly by the in-browser engine.
Browse the whole catalog
A searchable tree of schemas, tables, views, and functions, with row previews, column statistics, and on-demand profiling so you learn the data as you go.
Sign in and connect
One-click OAuth (Google and more) with per-source identity. Point Cupola at a live data source, share views as deep links, and theme it to match your team.
AI data analyst
Ask in plain English. Get answers in SQL.
Cupola’s built-in analyst is more than autocomplete. It reads your catalog, writes and runs real SQL against the in-browser engine, checks its own results, and explains what it found — so you can go from a vague question to a defensible answer without writing the first query yourself.
- Understands your schemas, tables, and column types
- Writes, runs, and refines SQL on the live data
- Explains results and suggests the next question
- Bring your own Anthropic API key — your data stays in your browser
Analyst
Running a query against volcanoes…
SELECT country, count(*) AS n
FROM volcanoes
WHERE last_eruption_year >= 1900
GROUP BY country
ORDER BY n DESC LIMIT 3;Indonesia (76), Japan (59), and the United States (53) lead — together about a third of all volcanoes active in the last century.
Try it now
Explore a live dataset in 30 seconds
We host an example data source — the Smithsonian global volcano catalog — so you can see Cupola work on real data without setting anything up.
Open the example
Launch Cupola pointed at our volcano data source. One link does it — no setup, no download.
Sign in with Google
The example source asks you to authenticate. Sign in with your Google account and you’re connected.
Query, pivot, or ask
Browse the catalog, run SQL in the shell, build a pivot, or ask the AI analyst a question.
Launch Cupola on the example volcano source:
https://cupola.query-farm.services/?service=https://vgi-volcanos.fly.dev
Heads up: the example source requires a quick Google sign-in to connect. Your data and queries stay in your browser.
Open source
Free, and yours to run
Cupola is Apache 2.0 licensed. Use the hosted version, or clone the repo and run it yourself — it’s a static site backed by DuckDB-WASM, with nothing to license and no server to operate.
For enterprise
Make it your team’s workbench
Cupola supports OAuth / PKCE sign-in, per-source identity, and full custom theming and branding. We help teams self-host it, white-label it, and wire it to their own internal data sources.
Talk about enterprise →Where it fits
Cupola and the rest of the data farm
Cupola is the place you actually work with data. Haybarn is the engine inside it; VGI and the Orchard are how you connect live sources to query.
Haybarn
The DuckDB engine that runs inside Cupola — and on the desktop or server when you outgrow the browser.
VGI
The protocol that turns APIs, services, and databases into the live SQL sources Cupola connects to.
Orchard
The marketplace of ready-made connectors you can open and explore directly inside Cupola.
See your data in a new light
Cupola is free, open source, and ready now. Open the live example, or bring your own source.