A world that reacts.
Your campaign tool decides what happened. Crowdsim says what people would say about it: the comments under the ad, why most people scrolled past, what the client thinks. Informed by this week's public conversation, with the sources to check, and labelled simulated every time.
An API, not a dashboard: it plugs into the tool you already use. Practice, not prediction.
Every dot is a person. Every person has an opinion.
A rushed first ad, and what came back.
A student ran one month of a default campaign: everyone in Canada, a stock product photo, "premium dog food for happy, healthy dogs". The campaign simulator produced the inputs. Crowdsim produced everything below them.
These numbers come from the caller's own engine. Crowdsim never changes a number.
- "Happy, healthy dogs" is what every dog food says, so nothing here told me why this one's different.
- No price, no deal, no idea if it's even Canadian, so I kept scrolling.
- I have cats, and it's just a bag and a bowl anyway.
The world learns from the world, and reacts to you.
Three parts, kept apart on purpose.
Nothing a user sends is ever training material. Worlds learn only from the pulse, from what customers say in public, and from real results a caller chooses to report. What students and trainees type gets a reaction, never a lesson.
An API, not a dashboard.
There is nothing to log into. Your simulator, your training tool or your own app sends one request with the decision and the numbers, and shows the reactions however it likes. Keys, usage, worlds and the pulse are endpoints too.
POST https://api.crowdsim.ca/v1/react Authorization: Bearer ae_… { "world": "quill-and-paw", "channel": "social", "decision": { "headline": "Know exactly what's in her bowl", … }, "outcome": { "orders": 14, "clicks": 561, "frequency": 1.9, … } } → { "simulated": true, "reactions": { "comments": [ … ], … } }
What the personas read this week.
Three of nine signals from the pet food world, 10 October 2026. Each dated to its own evidence, weighted for how much it should shape a reaction, and sourced.
Owners are cautious about price but still buying premium food
Pet Valu's same-store sales were flat; customers wait for promotions but keep spending on premium food. "How much?" comes early.
Buy Canadian is back since August, now argued on price
Counter-tariffs took effect 8 September; grocers brought back origin labels. "Is this Canadian?" is a live question.
The questions owners ask before they buy
Puppy or adult? Gluten? Live probiotics? Asked how high the protein is, the rival answered "a guaranteed minimum". Personas ask the same of any ad that doesn't answer.
A flight simulator for media planners and buyers.
Pilots don't learn crosswinds on a plane full of passengers. The simulator's weather is made up but probable, and an instructor can freeze the storm so every trainee flies the same one, or feed it live weather and let the session go wherever it goes. Everything in a Crowdsim persona's life works the same way: whether they notice an ad, whether a recall puts them on alert this week, whether the dog has a bad month. The only question is whether the dice are fixed.
Every student flies the same storm.
The instructor pins the week, the seed and the personas' lives. The same plan gives the same numbers for everyone, a marker can replay any of it, and the conditions can be set by hand: a recall in the news, a persona starting in a bad month.
Anything can happen.
Nothing is pinned. The weekly pulse moves the levers underneath the crowd, lives roll on, and the same plan run a week apart gets different results because the world changed. Practice on a messy public, with every number still traceable to a published rule.
One engine, any industry.
A world is a brief, a set of personas and a watch list. Bring your own client, or start from ours.
Early access, Winter 2027.
Crowdsim runs in a Canadian college classroom today and is opening its next worlds in January: new industries, new clients, and the first cohorts outside the course it was built in. If you teach, train or plan media and want a world of your own, leave an address and we'll write when yours is ready.