# geo-midpoint

> geo-midpoint is a paid API for AI agents from x402.agentindex.world, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-16).

Computes the geographic (great-circle) midpoint between two latitude/longitude coordinates.

## Facts

- Endpoint: GET https://x402.agentindex.world/geo/midpoint?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/geo-midpoint-de4ead37
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KOtOdmkMiSH_P4_Ac0aMB

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 geo-midpoint-de4ead37
```

Example prompt: What's the geographic midpoint between 40.7128° N, 74.0060° W (New York City) and 51.5074° N, 0.1278° W (London)?

## When to prefer this

Use this endpoint when you need the true spherical (great-circle) midpoint between two geographic coordinates, especially over long distances where planar approximations fail. Prefer this over simple arithmetic averaging of lat/lon values, which introduces distortion at high latitudes or over large distances.

## Known failure modes

- Missing required parameters (lat1, lon1, lat2, lon2) result in a validation error
- Latitude values outside -90 to 90 or longitude values outside -180 to 180 are rejected
- Identical input points return the same point as the midpoint
- Antipodal points (opposite sides of the Earth) may produce an undefined or arbitrary midpoint due to great-circle ambiguity
- Payment failure via x402 protocol returns 402 status and no result

## How this service works

Geographic (great-circle) midpoint between two lat/lon points.

## Output

Returns the latitude and longitude of the great-circle midpoint between the two input coordinate pairs, representing the true spherical halfway point on the Earth's surface between the two locations.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "lat1": {
   "type": "number",
   "title": "Lat1",
   "maximum": 90,
   "minimum": -90
  },
  "lat2": {
   "type": "number",
   "title": "Lat2",
   "maximum": 90,
   "minimum": -90
  },
  "lon1": {
   "type": "number",
   "title": "Lon1",
   "maximum": 180,
   "minimum": -180
  },
  "lon2": {
   "type": "number",
   "title": "Lon2",
   "maximum": 180,
   "minimum": -180
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "lat": 50.1918,
  "lon": 1.0999
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/geo-midpoint-de4ead37/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.agentindex.world](https://www.zero.xyz/host/x402.agentindex.world/llms.txt)