The Population APISimulix builds a population of American AI agents grounded in real demographics — for any place in the country — and answers questions about them in minutes.
We did not build this to disrupt anyone. We built it because the firms we work with told us they could no longer afford to spend $80,000 to learn which creative works. They wanted to know on Tuesday what the panels would have told them in three weeks.
— The editorsA direct-to-consumer brand came to us before their next paid-social flight. Six creative variants, four markets, one $80,000 test budget. They wanted to know which combinations would land — before lighting the budget on fire.
“You see this ad on Instagram for a $39 monthly meal kit promising ‘dinner in 12 minutes.’ Do you tap it?”
29 · Brand designer · Brooklyn, NY · 11211
20 of Jasmine’s 120+ attributes.
“Twelve minutes is the whole pitch. I’ll save it and check on payday. I’ve burned out on three meal kits already — I’m not signing up at 9 PM on a Wednesday.”
Every agent in the simulation carries this kind of shape. Demographics, household, work, consumer behavior, media diet, values — all anchored to a real place. The model writes the voice; the data decides who is in the room.
“Twelve minutes is the whole pitch. I’ll save it and check on payday.”
“$39 a month is two dinners out for our family. That’s not a meal kit, that’s a subscription I’ll forget about in three weeks.”
Killed two creatives before the flight. Reallocated $52,000 from Austin to Brooklyn and the Atlanta suburbs. Reworked the $39 price anchor in the Austin creative to “$1.30 per meal.” The campaign returned 2.3× the previous quarter’s CAC — measured against a control market they intentionally left untouched.
Simulix v1.0 launches today. The rows below are illustrative examples of the ledger shape — the kinds of questions we file, the column layout, the tolerance band. Real entries post here as we file them. Methodology open at simulix.com/methodology.
When the first real filing posts, the labelled examples above give way to dated entries — and the misses go on the same page, in the same column, with the same prominence.
See the benchmarks page →We are not the product on top. We are the population underneath. Research tools, audience platforms, agency dashboards, AI labs, political shops — they build on us. You can be running in ten minutes.
One key. Three primitives. A free tier with enough room to ship a prototype, and pricing you read on the page.
