geoprimitives

Measure how much ground a polygon covers, in square metres and square kilometres, with holes subtracted and every part of a MultiPolygon summed. Use it after POST /v1/geometry/intersect to size an overlap, or on a boundary you already hold. Points and lines contribute zero rather than an error, so a mixed collection is safe to send. Not turf's area, which applies the spherical-excess formula to geodetic latitudes on a 6371008.8 m sphere and comes out 0.45% high at the equator and 0.85% low at 80 deg latitude. This maps latitude to authalic latitude on the WGS 84 authalic sphere first, landing within 5e-3% of GeographicLib's geodesic area on parcel-scale rings and converging to 1e-6% as ring edges are densified. Ring edges are treated as straight in longitude/latitude, per RFC 7946 and turf; a geodesic-edge area differs on long slanted edges, by 1.9% on a 1.7-degree triangle. Winding order is ignored: ring 0 is the exterior and the rest are holes. Input is EPSG:4326 only. Limits: 100000 positions across the whole document, 1 MiB request body.

TradingLiveeip155:8453Exactvia cdp
GeometryPolygonAreaMeasurementWgs84
Calls · 30d
1→ 0%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 28 snapshots so far.
$4.40
Verified settled volume
885 settlements proven x402 by their on-chain EIP-3009 marker.
$0.010
Listed price
As published in the catalog. Always read the live 402 before paying.
1
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-08-21 17:25Z
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x76A51b5Dd3729950B3b60c17f19252d221968FCe

The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.

Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Provider

The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

0.01USDC≈ $0.01 USD
on Base · exact scheme

Pay 0.01 USDC on Base to 0x76A5…68FCe. The signed payment is good for 5 minutes.

USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
10000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x76A51b5Dd3729950B3b60c17f19252d221968FCe",
    "amount": "10000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "geojson": {
            "type": "Polygon",
            "coordinates": [
              [
                [
                  -150,
                  61
                ],
                [
                  -149.9,
                  61
                ],
                [
                  -149.9,
                  61.05
                ],
                [
                  -150,
                  61.05
                ],
                [
                  -150,
                  61
                ]
              ]
            ]
          }
        },
        "type": "http",
        "method": "POST",
        "bodyType": "json"
      },
      "output": {
        "type": "json",
        "example": {
          "op": "area",
          "area": 30122157.17615345,
          "unit": "m2",
          "notes": [],
          "accuracy": "Ellipsoidal (WGS 84) area, within about 5e-3% of a geodesic reference at parcel scale. Ring edges are straight in longitude/latitude, not geodesics.",
          "polygonCount": 1,
          "inputVertices": 5,
          "areaSquareKilometres": 30.12215717615345
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method",
            "bodyType",
            "body"
          ],
          "properties": {
            "body": {
              "type": "object",
              "required": [
                "geojson"
              ],
              "properties": {
                "geojson": {
                  "type": "object",
                  "description": "A GeoJSON Feature, FeatureCollection or Geometry in EPSG:4326, longitude then latitude in degrees. At most 100000 positions across the whole document. Points and lines contribute zero area."
                }
              },
              "additionalProperties": false
            },
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "POST"
              ],
              "type": "string"
            },
            "bodyType": {
              "enum": [
                "json",
                "form-data",
                "text"
              ],
              "type": "string"
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog
2026-08-21 17:25Z
Last indexed by Roundhouse
2026-09-20 17:20Z
Last enriched (probe, favicon, geo)
2026-09-23 21:45Z
x402 version
2
Max timeout
300s
Liveness probe
HTTP 404
Report

Hand this page to an agent

Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.

GET api.roundhouseai.io/v0/endpoints

This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 28 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.

Open skill.md
Show the prompt
Using Roundhouse, look up the x402 service geoprimitives and tell me whether it is
worth paying: what a call costs, whether the endpoint answered when last probed, and what
its payment record actually shows.

curl -s 'https://api.roundhouseai.io/v0/endpoints?q=geoprimitives'
curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>'

Then call it: read the price from the live 402 at https://api.geoprimitives.dev/v1/geometry/area, never from
a cached figure, and pay with an x402 client.

The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except
/v0/unified* and /v0/endpoints. Mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402,
or use an organization key from https://roundhouseai.io/dashboard/team.

If you do not have Roundhouse tools or skills installed, read
https://roundhouseai.io/skill.md first — it is the whole procedure.