# Wind Load API
> Structural wind-load maths as an API, computed locally and deterministically. The pressure endpoint computes the velocity (dynamic) pressure of wind, q = ½·ρ·v², from the wind speed and air density — the pressure the wind exerts when it is brought to rest against a surface — and also solves the wind speed back from a given pressure, reporting the speed in m/s, km/h and mph. The force endpoint computes the wind force on a surface, F = q·Cf·A, from the velocity pressure (or wind speed), the exposed area and a force coefficient (≈1.3 for a building wall, ≈1.2 for a flat plate), and — given a height — the overturning moment about the base. The beaufort endpoint converts between a wind speed and the Beaufort scale using v = 0.836·B^1.5, returning the Beaufort number, the standard description from calm to hurricane force and the corresponding pressure. Everything is computed locally and deterministically, so it is instant and private. Ideal for structural and façade-engineering tools, signage, solar-array, scaffold and temporary-structure wind checks, sailing and meteorology apps, and engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is structural wind pressure and force; for wind-turbine energy output use a wind-power API.

## Authentication
All requests require your oanor API key in the `x-oanor-key` header. Get one at https://www.oanor.com/developer/keys.

```bash
curl -H "x-oanor-key: oanor_live_…" "https://api.oanor.com/windload-api/..."
```

## Pricing
- **Free** (Free) — 2,000 calls/Mo, 2 req/s
- **Starter** ($9/Mo) — 25,000 calls/Mo, 5 req/s
- **Pro** ($24/Mo) — 150,000 calls/Mo, 15 req/s
- **Mega** ($75/Mo) — 1,019,000 calls/Mo, 40 req/s

## Endpoints

### Wind Load

#### `GET /v1/beaufort` — Beaufort conversion

**Parameters:**
- `wind_speed` (query, optional, string) — Wind speed v (m/s) Example: `20`
- `beaufort` (query, optional, string) — Or Beaufort number (0–12) Example: `8`
- `air_density` (query, optional, string) — Air density ρ (kg/m³, default 1.225) Example: `1.225`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/windload-api/v1/beaufort?wind_speed=20&beaufort=8&air_density=1.225"
```

**Response:**
```json
{
    "data": {
        "note": "Beaufort relation v = 0.836·B^1.5 m/s. Description from the standard 0–12 Beaufort scale.",
        "inputs": {
            "air_density": 1.225
        },
        "solved_for": null,
        "description": "Gale",
        "wind_speed_ms": 20,
        "beaufort_exact": 8.3026,
        "wind_speed_kmh": 72,
        "beaufort_number": 8,
        "velocity_pressure_pa": 245
    },
    "meta": {
        "timestamp": "2026-06-04T18:38:26.232Z",
        "request_id": "0e16b61d-907f-4858-998a-70a1ece53d46"
    },
    "status": "ok",
    "message": "Beaufort conversion",
    "success": true
}
```

#### `GET /v1/force` — Wind force on a surface

**Parameters:**
- `area` (query, required, string) — Exposed area A (m²) Example: `10`
- `wind_speed` (query, optional, string) — Wind speed v (m/s) Example: `30`
- `pressure` (query, optional, string) — Or velocity pressure (Pa)
- `force_coefficient` (query, optional, string) — Force coefficient Cf (default 1.3) Example: `1.3`
- `height` (query, optional, string) — Height (m) for overturning moment Example: `5`
- `air_density` (query, optional, string) — Air density ρ (kg/m³, default 1.225) Example: `1.225`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/windload-api/v1/force?area=10&wind_speed=30&force_coefficient=1.3&height=5&air_density=1.225"
```

**Response:**
```json
{
    "data": {
        "note": "F = q·Cf·A. Cf is the force/pressure coefficient (≈1.3 for a typical building wall, ≈1.2 for a flat plate).",
        "inputs": {
            "area": 10,
            "wind_speed": 30,
            "air_density": 1.225,
            "force_coefficient": 1.3
        },
        "height_m": 5,
        "note_moment": "Overturning moment about the base assumes a uniform pressure with the resultant at mid-height.",
        "wind_force_n": 7166.25,
        "wind_force_kn": 7.16625,
        "velocity_pressure_pa": 551.25,
        "overturning_moment_nm": 17915.625
    },
    "meta": {
        "timestamp": "2026-06-04T18:38:26.332Z",
        "request_id": "bd75cf1b-0398-4108-aa4d-cfa087c6c5cb"
    },
    "status": "ok",
    "message": "Wind force",
    "success": true
}
```

#### `GET /v1/pressure` — Velocity pressure

**Parameters:**
- `wind_speed` (query, optional, string) — Wind speed v (m/s) Example: `30`
- `pressure` (query, optional, string) — Or a pressure (Pa) to solve the speed
- `air_density` (query, optional, string) — Air density ρ (kg/m³, default 1.225) Example: `1.225`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/windload-api/v1/pressure?wind_speed=30&air_density=1.225"
```

**Response:**
```json
{
    "data": {
        "note": "q = ½·ρ·v² (Pa). Standard air density ρ ≈ 1.225 kg/m³ at 15 °C.",
        "inputs": {
            "wind_speed": 30,
            "air_density": 1.225
        },
        "solved_for": null,
        "wind_speed_kmh": 108,
        "wind_speed_mph": 67.1081,
        "velocity_pressure_pa": 551.25,
        "velocity_pressure_kpa": 0.55125
    },
    "meta": {
        "timestamp": "2026-06-04T18:38:26.418Z",
        "request_id": "05a58347-afe2-4ff6-8344-dc7b5bf69fd1"
    },
    "status": "ok",
    "message": "Velocity pressure",
    "success": true
}
```

### Meta

#### `GET /v1/meta` — Spec

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/windload-api/v1/meta"
```

**Response:**
```json
{
    "data": {
        "notes": "Wind speed in m/s, area in m², density in kg/m³ (default 1.225), force in N. Simplified rigid-body model — gust effect factors, exposure and topography from a building code are not applied.",
        "service": "windload-api",
        "formulae": {
            "force": "F = q·Cf·A",
            "beaufort": "v = 0.836·B^1.5 (m/s)",
            "velocity_pressure": "q = ½·ρ·v²"
        },
        "endpoints": {
            "GET /v1/meta": "This document.",
            "GET /v1/force": "Wind force F = q·Cf·A on a surface, with overturning moment for a given height.",
            "GET /v1/beaufort": "Convert between wind speed and the Beaufort scale, with description and pressure.",
            "GET /v1/pressure": "Velocity pressure q = ½ρv²; solves wind speed from a pressure."
        },
        "description": "Structural wind-load calculator: velocity (dynamic) pressure, wind force on a surface with overturning moment, and Beaufort-scale conversion."
    },
    "meta": {
        "timestamp": "2026-06-04T18:38:26.525Z",
        "request_id": "1d59d033-8129-48e8-9152-f265527e44a4"
    },
    "status": "ok",
    "message": "Meta",
    "success": true
}
```


---
Marketplace page: https://www.oanor.com/api/windload-api
OpenAPI spec: https://www.oanor.com/api/windload-api/openapi.json