# Wave Function Collapse — Randomly

> Overlapping model, min-entropy heuristic, backtracking. One of 63 generators at [Randomly](https://randomly.cluxnei.dev), a library of random generators seeded from verifiable real-world entropy. Free HTTP API, no key, no signup.

## `patterns.wfc` — Wave Function Collapse

Overlapping model, min-entropy heuristic, backtracking.

| | |
|---|---|
| **Key** | `patterns.wfc` |
| **Module** | `patterns` |
| **Version** | `1` — a permalink carries this, and a replay against a different version returns `409` rather than something else |
| **Formats** | `application/json`, `text/plain`, `image/png` |
| **Studio** | https://randomly.cluxnei.dev/g/patterns/wfc |
| **API** | `GET https://randomly.cluxnei.dev/api/v1/g/patterns.wfc` |

`value` is a **render spec** — algorithm, parameters, palette and a render key — not pixels. Ask for `format=png` to get the image.

| Parameter | Type | Default | Accepts | What it does |
|---|---|---|---|---|
| `width` | int | `960` | `200` – `2048` | Width |
| `height` | int | `640` | `200` – `2048` | Height |
| `sample` | enum | `knot` | `knot`, `maze`, `rooms`, `circuit`, `weave`, `blossoms` | Sample |
| `n` | int | `3` | `2` – `3` | Window size (N) — How much context a pattern carries. N = 2 knows only which pairs of cells may touch and produces something loose; N = 3 knows whole corners, and is where the output starts looking authored. |
| `symmetry` | enum | `8` | `1`, `2`, `4`, `8` | Symmetry — Which transforms of each pattern are also admitted. More symmetry means a richer output from the same sample, and a larger pattern set to propagate through. |
| `tiles` | int | `74` | `8` – `140` | Cells across — Measured across the long side. The solve is cells × patterns × adjacency, so this is the control that decides whether the render is instant or merely fast. |
| `palette` | enum | `viridis` | `golden`, `analogous`, `complementary`, `triadic`, `split`, `viridis`, `magma`, `mono` | Colour |
| `grain` | float | `0.01` | `0` – `0.06` | Grain |

Out-of-range numbers are **clamped, not rejected**, so a request never fails for being
ambitious — but it may not do what you meant. Unknown keys are dropped and missing ones
fall back to the defaults above.

```bash
curl -s 'https://randomly.cluxnei.dev/api/v1/g/patterns.wfc?width=960&height=640&sample=knot' -H 'Accept: text/plain'
curl -o out.png 'https://randomly.cluxnei.dev/api/v1/g/patterns.wfc?width=960&height=640&sample=knot&format=png'
```

## The receipt

Every result carries one, naming the physical source of the randomness and linking to the
third party's own record of it:

```json
"receipt": {
  "source": "seismic",
  "source_label": "USGS Seismic Feed",
  "class": "C",
  "caveat": "Carries only tens of bits of genuine surprise. Always mixed with the OS CSPRNG.",
  "narrative": "A magnitude 3.6 earthquake, 67 km N of Culebra, Puerto Rico, 39.6 km down — 52 minutes ago.",
  "proof_url": "https://earthquake.usgs.gov/earthquakes/eventpage/us7000th33",
  "mixed_with_csprng": true,
  "degraded": false
}
```

Pick the source with `?source=`, or leave it at the default `auto`:

- **Class A** (Cryptographic) — `csprng`, `anu-qrng`, `random-org`
- **Class B** (Public beacon) — `nist-beacon`, `drand`, `bitcoin`. Published openly — anyone can look this value up after the fact.
- **Class C** (Observational) — `seismic`, `space-weather`, `atmosphere`, `iss`. Carries only tens of bits of genuine surprise. Always mixed with the OS CSPRNG.

## More

- [The full API contract](https://randomly.cluxnei.dev/api.md)
- [Everything in one file](https://randomly.cluxnei.dev/llms-full.txt)
- [The catalogue as JSON](https://randomly.cluxnei.dev/api/v1/generators)
- [This generator in the browser](https://randomly.cluxnei.dev/g/patterns/wfc)