The house brain: running with no model at all
The house brain is a deterministic personality heuristic that answers the same nine questions and synthesises its own distributions, so the simulation stays watchable, and tunable, with no API key and no network.
house() in lib/sim/brain.ts implements the same interface as the model: same nine questions, same answer types, distributions included. The engine cannot tell which one it is talking to.
What it buys
- A site that always works. Clone it, run it, watch a party, with no account, no key and no spend.
- Free tuning. Every rule in the engine can be exercised and watched without paying for a single call.
- Deterministic tests. Seeded, the house brain plays the same party every time, which is what makes headless dry-runs a regression net and not a demo.
- Somewhere to fall back to. Out of budget or out of key, the room degrades instead of stopping.
What it is not
It is not the product. A heuristic that reads its own state cannot surprise you: it has no sense of a room being tense, only of numbers being high. The difference shows up immediately in how flat its distributions are, where every near-miss is a formula.
The UI labels the brain in full detail for that reason. A watcher should never be unsure which one they are looking at.
Read next
typesafe-ai/jev, and what Parlour uses it for
Jev is the evaluation model Parlour runs on. It answers nine typed questions per character per beat in one call, is billed on input tokens only, and costs roughly three cents for a five-minute party.
Running it through the Vercel AI Gateway
Parlour reaches Jev through the Vercel AI Gateway with one server-side key, and reads live per-token prices from the Gateway's model catalogue, so the cost counter on screen is a real number and not a constant.
Playing a whole world in the terminal
A party plays in the terminal with no browser and no server, and a village year plays in under a second. Both run on the same primitives as the live simulation, so a rule that works headless works live.
Two guard rails on a public LLM toy
Nothing ticks in a room nobody has opened. A party already under way plays to its end and then stops. A rolling hourly cap drops a room to the house brain past a fixed dollar figure.