Run the Ctrl-F for Video demo

The demo this project grew out of. You type "a diagram with boxes and arrows", get back frames from conference talks nobody captioned, click one, and the video plays at that second — while an instrument shows how few bytes moved.

Build the corpus

bash

make ingest LIMIT=8

Downloads FOSDEM recordings (CC-BY), segments them, extracts keyframes, embeds each one with SigLIP, and writes two Lance tables: moments and segments. The video ends up inside segments in a Blob V2 column.

It is gigabytes and takes a while. LIMIT controls how many talks.

Run it

bash

make demo      # production build, API warmed before the browser can reach it
make dev       # hot reload, for building rather than presenting

After a git pull, run make setup before either. A pull updates package.json and uv.lock; it does not install anything, so a newly added dependency arrives declared and absent. The launcher checks for this and stops with a sentence rather than failing in the middle of a production build.

The demo is at /demo, the console at /console.

Check the claims

bash

make verify

Reads Lance's own IO counters and fails if anything in the README has stopped being true. On the reference corpus:

operation	index bytes	video bytes
semantic search over every moment	3.45 MB	0
full-text search over transcripts	0.11 MB	0
open a blob handle	—	2,722
start playback (cold segment)	—	~17 MB, one segment
seek again inside it (warm)	—	262,144, byte-exact

Zero is not "very little". The video bytes are not in the files a search opens.

Why the demo matters to the console

Every claim the console makes about blob columns was measured here first — including the ones that turned out to be wrong on the first try. The manifest cannot see side files. A blob column projects a descriptor rather than bytes, so selecting one is safe. The columns that actually cost something are the ordinary ones: thumb_jpeg takes a page of rows from 34 KB to 383 KB.