Make the next video faster

The first video in a project pays for the setup: init, the login, the first captures, and an agent getting to know your product. Later videos reuse all of that.

What carries over#

Already done	Kept in
Brand, glossary, routes	`.demovie/brand/`, `glossary.md`, `routes.json`
Login	`.demovie/config.json`, `.demovie/.env`, `.demovie/.auth/`
Screenshots and element maps	`.demovie/captures/` (until your UI changes)
Earlier videos to learn from	`.demovie/videos/<slug>/` (brief, storyboard, composition)
Rendered frames	`.demovie/.cache/frames/` (unchanged frames aren't redrawn)

Ask for less#

The biggest savings come from a smaller request:

A shorter type. A teaser (8–15 s) or a feature clip (20–35 s) instead of a 35 s launch.
One format. Each extra format is another full check and render.
One part of the app. Name it, so the agent starts from the right captures.

npx demovie make --type teaser --format 9:16 --about "the QR code pickup"

Or, in the session where your agent made the last video:

Now a 12-second vertical teaser of the QR code pickup, in the same style.

Staying in the same session helps most: the agent already knows your captures, your brand and what worked.

Refresh only what changed#

After you change the UI, recapture just what your changes touched:

npx demovie capture --changed

or one page:

npx demovie capture --route "/app/qr-code" --viewport mobile

npx demovie status lists stale captures.

Iterate cheaply#

Small edits stay small. "Hold the second shot longer" or "use our green for the CTA" changes a few lines, and the next render only redraws the frames that changed.
Look before rendering. npx demovie stills launch --at 2,8,15 --sheet makes a contact sheet in seconds; npx demovie preview launch lets you scrub.
Draft first. npx demovie render launch --quality draft --format 16:9 is fast; render final once.

How long things take#

On a recent MacBook, for reference:

Step	Time
Capture 18 screens and flow states (app already running)	about 20 s
QA on one 35 s video, one format	under a minute
Final render of a 35 s video at 1080p	about 1 minute per format
A first launch video by an agent, end to end	20–60 minutes
A 12 s teaser in a project that's already set up (Harborly, `make --yes`, Opus 5.5)	3 min 21 s, $1.06

Agent time and cost depend on the model and its effort setting. make prints both at the end.

Keep the disk tidy#

Rendered frames are kept so re-renders are fast, and they add up to gigabytes. npx demovie status warns when they pass 2 GB; npx demovie clean frees them (the next render redraws what it needs).