Demo data

Videos show your product with data in it. demovie never invents that data: it captures what your app renders, so the app needs a demo seed — a script that fills a fresh database (or fixture store) with believable, fictional data.

Wiring it up#

jsonc

"demo": {
  "seed": "pnpm demo:seed",          // runs before the app starts and before every capture run
  "now": "2026-09-15T10:30:00.000Z"  // the page clock is frozen here, so "3 days ago" and charts stay stable
}

The seed must be idempotent: running it twice gives the same data. Flows that create things (a new project) then replay cleanly on every capture.

Writing good demo data#

Fictional, never real. No real customers, people, emails or companies. Use a reserved domain for emails (@yourapp.demo, example.com) and add it to demo.mask.allow.
Plausible and specific. "Q3 Launch", "Billing migration", "Northwind" read better than "Project 1".
Varied states. Some items on track, some at risk, one overdue; progress at 20%, 65%, 100%. Videos need contrast.
Dated relative to demo.now. Generate dates from a fixed reference so charts and "due in 3 days" match the frozen clock.
Deterministic. No Math.random() without a seed, no Date.now().
A demo login. One fixture user (e.g. demo@yourapp.demo) whose password lives in .demovie/.env.

Every number your video shows should appear in the captured UI, the glossary or the brief; QA rule DM-G04 warns about numbers it can't find there.

Example#

The examples/harborly fixture (pnpm --filter harborly demo:seed) seeds projects across four columns, people, customers, activity and weekly velocity from one file, all relative to a fixed date.