# Vextorium Geodesic Distance Calculator

> Vextorium Geodesic Distance Calculator is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-16).

Computes the geodesic (Vincenty WGS84) and great-circle distance between two coordinates, returning distance in km/miles/nautical miles, initial bearing, compass direction, midpoint, and estimated travel times by foot, car, and plane.

## Facts

- Endpoint: POST https://api.vextorium.com/geo-distancia-pago?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vextorium-geodesic-distance-calculator-ded5e571
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6fro0Oq7KTXR1-KTZV7QD

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability vextorium-geodesic-distance-calculator-ded5e571 -d '<json body>'
```

Example prompt: What's the straight-line distance between Madrid (40.4168, -3.7038) and Barcelona (41.3851, 2.1734)? I need the result in km, miles, and nautical miles, plus the initial compass bearing and an estimate of how long the trip would take by foot, car, and plane.

## When to prefer this

Choose this endpoint when you need precise geodesic distance between two coordinate pairs using the accurate Vincenty WGS84 formula, especially when you also need bearing, midpoint, and multi-unit output (km, miles, nautical miles) plus travel time estimates in a single call. Prefer it over simple Haversine-based tools when geodetic accuracy matters (e.g. long distances where Earth's ellipsoidal shape is significant), or when you need compass direction and travel time estimates bundled together without additional calls.

## Known failure modes

- Missing required lat1/lon1/lat2/lon2 fields returns a validation error
- Coordinates outside valid range (lat: -90 to 90, lon: -180 to 180) may cause computation errors
- Identical coordinates may return zero distances and undefined bearing
- Payment failure via x402 protocol results in access denied
- Malformed JSON body returns a parse error

## How this service works

Distance between two coordinates (Vincenty geodesic on WGS84 plus great-circle), in km, miles and nautical miles, initial bearing and compass direction, midpoint and estimated time on foot, by car and by plane.

## Output

A JSON object containing: distance in km (Vincenty), distance in miles, distance in nautical miles, great-circle distance in km, initial bearing in degrees, compass direction label (e.g. 'E'), midpoint latitude and longitude, estimated travel time in hours on foot at 5 km/h, by car at 80 km/h, and by plane at 800 km/h, plus a note that the distance is straight-line (not road distance) and the method used (Vincenty WGS84).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "lat1": {
   "type": "number"
  },
  "lat2": {
   "type": "number"
  },
  "lon1": {
   "type": "number"
  },
  "lon2": {
   "type": "number"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "nota": "Distancia en línea recta, no por carretera.",
  "rumbo": "E",
  "metodo": "Vincenty WGS84",
  "punto_medio": {
   "lat": 40.939351,
   "lon": -0.789164
  },
  "distancia_km": 506.3,
  "distancia_millas": 314.6,
  "tiempo_estimado_h": {
   "a_pie_5kmh": 101.26,
   "coche_80kmh": 6.33,
   "avion_800kmh": 1.13
  },
  "rumbo_inicial_grados": 75.75,
  "distancia_esferica_km": 505.096,
  "distancia_millas_nauticas": 273.38
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vextorium-geodesic-distance-calculator-ded5e571/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)