# Saylor Innovations Polygon Geometry Calculator

> Saylor Innovations Polygon Geometry Calculator is a paid API for AI agents from saylorinnovations.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-27).

Computes area (km², hectares, acres, sq miles), perimeter, centroid, and bounding box for a polygon defined by lat/lon vertices, with optional point-in-polygon test

## Facts

- Endpoint: GET https://saylorinnovations.com/api/geo/polygon?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/saylor-innovations-polygon-geometry-calculator-342d215d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_s7Prnr_dhJ2IAUc7-jAf3

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 saylor-innovations-polygon-geometry-calculator-342d215d
```

Example prompt: Can you calculate the area, perimeter, and centroid of the land parcel with these vertices: 40.7128,-74.0060; 40.7138,-74.0050; 40.7125,-74.0040; 40.7115,-74.0055 — and also tell me if the point 40.7122,-74.0052 falls inside it?

## When to prefer this

Choose this endpoint when you need geospatial polygon metrics — area, perimeter, centroid, bounding box — from raw lat/lon coordinate lists, especially when you also need a point-in-polygon containment test in the same call. It supports multiple area units (km², hectares, acres, sq miles) simultaneously, making it ideal for land surveying, property analysis, delivery zone verification, and GIS workflows where you don't want to spin up a full GIS library.

## Known failure modes

- Fewer than 3 vertices provided — polygon cannot be formed
- Malformed points string (wrong separator or missing coordinate) — parse error
- Points string exceeds 500 vertices — rejected
- Invalid lat/lon values (out of range) — computation error
- Missing required 'points' query parameter — 400 bad request
- Payment not processed — 402 payment required

## How this service works

Polygon area in km2, hectares, acres and square miles from lat,lon vertices, plus perimeter, centroid, bounding box and a point-in-polygon test

## Output

Returns a JSON object with the polygon vertex count, area in km², hectares, acres, and square miles, perimeter in km and miles, planar centroid lat/lon, bounding box coordinates, and — if a test point was provided — an object containing the test lat/lon and a boolean indicating whether the point is inside the polygon. May also include source and note fields for context.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "points"
     ],
     "properties": {
      "points": {
       "type": "string",
       "description": "Vertices written lat,lon;lat,lon;... (3-500)"
      },
      "test_point": {
       "type": "string",
       "description": "optional lat,lon to test whether it lies inside"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object",
     "required": [
      "vertices",
      "area_km2",
      "perimeter_km",
      "centroid"
     ],
     "properties": {
      "note": {
       "type": "string",
       "description": "Caveat or context for reading the result"
      },
      "source": {
       "type": "string",
       "description": "Data source the values come from"
      },
      "area_km2": {
       "type": "number",
       "description": "Area km2"
      },
      "centroid": {
       "type": "object",
       "description": "Planar centroid latitude and longitude"
      },
      "vertices": {
       "type": "number",
       "description": "Number of polygon vertices"
      },
      "area_acres": {
       "type": "number",
       "description": "Area acres"
      },
      "test_point": {
       "type": [
        "object",
        "null"
       ],
       "properties": {
        "lat": {
         "type": [
          "number",
          "null"
         ],
         "description": "Latitude in decimal degrees"
        },
        "lon": {
         "type": [
          "number",
          "null"
         ],
         "description": "Longitude in decimal degrees"
        },
        "inside": {
         "type": [
          "boolean",
          "null"
         ],
         "description": "True when the test point is inside the polygon"
        }
       },
       "description": "Test point"
      },
      "bounding_box": {
       "type": "object",
       "description": "Bounding box"
      },
      "perimeter_km": {
       "type": "number",
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/saylor-innovations-polygon-geometry-calculator-342d215d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from saylorinnovations.com](https://www.zero.xyz/host/saylorinnovations.com/llms.txt)