Sparrow — Iceberg stops at the files. Sparrow starts at the serving index. I wrote the clients.

Sparrow — Iceberg stops at the files. Sparrow starts at the index.
…and I wrote the clients.
The missing client toolkit for Apache Arrow Flight. Flight moves columnar data at wire speed — but the client side of the ecosystem is thin. Sparrow fills it: five clients, one protocol — the terminal, the browser, the spreadsheet, your agents, and a diagnostic.
Terminal
sparrowCLI — Go, for humans and agents: catalog, SQL, Parquet/CSV export, a connection doctor, verifiable receipts
Browser
sparrowJS — TypeScript, on npm: Flight SQL over gRPC-web, streaming record batches into the page
Excel
sparrowXL — a native add-in streaming Arrow straight into the grid
Agents
sparrowMCP — any Flight endpoint speaks MCP (Model Context Protocol)
X-ray
Flight Inspector — point it at any Flight SQL server: conformance, catalog, wire anatomy
They work with other people's servers too — Dremio, Spice.ai, InfluxDB Cloud — not just ours. The CLI is validated against five vendors; the Inspector reaches them live.
Underneath, for the live demos: the Sparrow serving engine — a file that feels like a database. The serving index ships with the data; a server memory-maps the snapshot and starts answering. 8 ms from a local file, 27 ms across the LAN. Every demo on this site runs against its public endpoint — the energy data there is just the demo. The tools are the product.

Clients

CLI — terminal JS — browser Excel — XLL add-in MCP — for agents

Try it live

Live demos Inspect — X-ray a server Connect — public endpoint

Learn & proof

Arrow Flight explained EnergyScope — in production Benchmarks Contact — say hello
sparrowflight.io · 2026