# Spherical Route Great-Circle Leg Bearings

> Spherical Route Great-Circle Leg Bearings is a paid API for AI agents from detect.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-11-04).

Computes the great-circle arc length and initial departure bearing for each leg of a multi-point spherical route.

## Facts

- Endpoint: POST https://detect.halowerk.com/v1/F-TD2000-GEO-INDUSTRY-B001/spherical-route-great-circle-leg-bearings?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-04
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/spherical-route-great-circle-leg-bearings-7f52ce18
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uxfz178u1mDx_dKj8GpXS

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 spherical-route-great-circle-leg-bearings-7f52ce18 -d '<json body>'
```

Example prompt: Calculate the great-circle leg lengths and departure bearings for a 4-stop route on a sphere of radius 6371 km, using waypoints [48.8566, 2.3522], [51.5074, -0.1278], [40.7128, -74.0060], and [35.6762, 139.6503].

## When to prefer this

Choose this endpoint when you need precise great-circle leg-by-leg bearing and arc length decomposition for a multi-waypoint route on any sphere (Earth, other planetary bodies, or custom radius). Ideal when you need both distance and initial heading per segment in a single call, rather than just point-to-point distance. Well-suited for aviation, maritime, orbital, or geodesic planning workflows that handle sequences of 2–64 waypoints.

## Known failure modes

- Fewer than 2 waypoints provided — minimum is 2 points to form at least one leg
- Waypoint arrays with other than exactly 2 elements (not [lat, lon] pairs)
- Radius outside allowed range (1 to 10,000,000) causes validation error
- More than 64 waypoints submitted — exceeds maxItems limit
- Coordinate values outside the allowed range (-1,000,000 to 1,000,000)
- Missing required fields sphereRoute.data.points or sphereRoute.data.radius returns schema error
- Payment failure or insufficient USDC balance returns 402

## How this service works

Compute spherical route lengths and each departure bearing.

## Output

Returns an artifact containing per-leg great-circle arc lengths (in the same units as the input radius) and the initial departure bearing (in degrees) for each consecutive pair of waypoints along the route, along with a claim object for verification.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "artifact": {
   "type": "object",
   "required": [
    "sphereRoute"
   ],
   "properties": {
    "sphereRoute": {
     "type": "object",
     "required": [
      "data",
      "claim"
     ],
     "properties": {
      "data": {
       "type": "object",
       "required": [
        "points",
        "radius"
       ],
       "properties": {
        "points": {
         "type": "array",
         "items": {
          "type": "array",
          "items": {
           "type": "number",
           "maximum": 1000000,
           "minimum": -1000000
          },
          "maxItems": 2,
          "minItems": 2
         },
         "maxItems": 64,
         "minItems": 2
        },
        "radius": {
         "type": "number",
         "maximum": 10000000,
         "minimum": 1
        }
       },
       "additionalProperties": false
      },
      "claim": {}
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/spherical-route-great-circle-leg-bearings-7f52ce18/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from detect.halowerk.com](https://www.zero.xyz/host/detect.halowerk.com/llms.txt)