# The engines underneath.

> For the complete documentation index, see [llms.txt](https://acaysia.com/llms.txt); a single-file corpus of every page is at [llms-full.txt](https://acaysia.com/llms-full.txt). Every page in that index is served as Markdown: append `.md` to its URL or send `Accept: text/markdown`.

Canonical: https://acaysia.com/platform

Simulation fast enough to control against.

Acaysia's controller samples thousands of futures every tick and steers along their cost-weighted path. The models behind each reactor are trained on AcaysiaRT, AcaysiaDRT and Rete, so the controller looks ahead before it moves a setpoint, and hands back to your PID in under 100 ms.

**One reactor, four resolutions** (schematic):

1. **Shape — AcaysiaGEM.** The vessel, fit to simulate.
2. **Field — AcaysiaDRT.** Every cell resolved in 3D.
3. **State — AcaysiaRT.** Lumped state, stepped in time.
4. **Plant — Rete.** One unit in a plant with recycle.

## The platform

1. [AcaysiaRT](https://acaysia.com/engines/acaysia-rt.md) — Simulation runtime. 127 registered process models.
2. [Rete](https://acaysia.com/engines/acaysia-rt.md#rete) — Whole-plant flowsheets. Recycle included.
3. [AcaysiaDRT](https://acaysia.com/engines/acaysia-drt.md) — Spatial simulation. Lattice Boltzmann, full 3D.
4. [AcaysiaGEM](https://acaysia.com/engines/acaysia-gem.md) — Geometry. 18 parametric geometries.
5. [AcaysiaCORE](https://acaysia.com/core.md) — Simulation in the browser. Coming soon.

## How it fits

### Four engines, one surface.

Each engine answers a different question about the same plant. All four speak one contract family, and AcaysiaCORE serves them from one surface.

GEM builds the vessel, DRT resolves it in 3D on top of AcaysiaRT, and Rete wires AcaysiaRT models into whole plants. AcaysiaCORE brings all four into a single browser application.

Schematic — four engine domains (AcaysiaRT: 127 process models; Rete: plants with recycle; AcaysiaDRT: 3D spatial fields; AcaysiaGEM: vessel geometry) converge through one contract family into one AcaysiaCORE surface (one surface, one login), served to a single browser (analysis, no install).

## AcaysiaRT throughput

### 6.1B reactor-steps per second.

On one RTX 5080. AcaysiaRT is the runtime underneath the Acaysia MPPI control system — fast enough to sample thousands of futures every control tick.

[AcaysiaRT](https://acaysia.com/engines/acaysia-rt.md)

## The Acaysia Control System

### See Acaysia in action.

PID fallback in under 100 ms. Start with a discovery call about your process, or ask for early access to AcaysiaCORE and run the engines from your browser.

[Book a discovery call](https://acaysia.com/contact.md) · [Request CORE early access](https://acaysia.com/contact.md)