> ## Documentation Index
> Fetch the complete documentation index at: https://docs.footstep.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Spatial probability predictions powered by Footstep Nova

<Warning>
  **Research Preview** — The Predict API is a research preview. Predictions are generated from behavioural models that have not yet been fully validated against real-world outcomes. This endpoint is not intended for use as the sole or primary basis for operational search and rescue decisions. Access is granted on request — contact [support@footstep.ai](mailto:support@footstep.ai) to get started.
</Warning>

## Predict API

The Predict API generates spatial probability distributions for missing person scenarios. Given a search area, subject profile, and environmental conditions, it returns per-hex probabilities across an [H3](https://h3geo.org/) grid — telling you where to look first.

## Models

### Footstep Nova family

Footstep Nova is a family of spatial prediction models purpose-built for missing person scenarios. Nova models combine terrain analysis, land use classification, points of interest, weather conditions, and time-of-day signals to predict the most likely locations for a subject based on their behavioural profile.

Nova supports multiple behavioural profiles. Each model accounts for how different subject types interact with their environment — a despondent individual moves differently to someone with dementia.

#### footstep-nova-1

The first release in the Nova family. Nova 1 delivers profile-aware, weather-aware spatial predictions across flexible search areas.

***

## Key capabilities

* **Profile-aware predictions** — select a behavioural profile that matches your subject. Each profile produces a distinct probability distribution based on how that subject type interacts with the environment.
* **Directional search** — when the initial direction of travel is known, results are automatically focused to a directional cone, reducing noise and prioritising the most relevant area.
* **Weather-aware** — the model factors in temperature, precipitation, and wind conditions. Weather is fetched automatically or can be overridden for historical analysis.
* **Flexible search areas** — define your area as a circle, polygon, or buffered path. The API handles hex grid generation and clipping.

## How to use it

1. Choose a **profile** matching the subject's behavioural category.
2. Define a **search area** — circle (centre + radius), polygon (GeoJSON), or buffered path.
3. Provide **subject parameters** — age, optional direction of travel, and date/time.
4. The API returns a ranked list of hexagons with probabilities. Higher probability hexes should be searched first.

## Endpoint

| Endpoint                                    | Description                                                       |
| ------------------------------------------- | ----------------------------------------------------------------- |
| [`POST /v1/predict`](/api/endpoint/predict) | Generate spatial predictions for a given profile and search area. |

## Area types

| Type      | Fields                                     | Max size     |
| --------- | ------------------------------------------ | ------------ |
| `circle`  | `center` (lat/lng) + `radius_m`            | 5 km radius  |
| `polygon` | GeoJSON `Polygon` geometry                 | 25 km²       |
| `path`    | GeoJSON `LineString` geometry + `buffer_m` | 500 m buffer |

## Weather

By default, the API fetches weather conditions automatically based on the search area centre and the provided `datetime`. You can:

* **Override weather** — pass a `weather` object with `temperature_c`, `precipitation_mmh`, `wind_speed_mps`, and `wind_direction_deg`.
* **Disable weather** — set `disableWeather: true` to use neutral defaults.

## Confidence

The response includes a `confidence` level (`high`, `medium`, or `low`) indicating how well the model performs in the region of the search area.

## Access

The Predict API is available on request. Contact [support@footstep.ai](mailto:support@footstep.ai) to enable it on your account.

Once enabled, authentication works the same as all other endpoints — pass your `x-api-key` header. See the [authentication guide](/authentication) for details.