# Map Tile Maths – Mercator Projection (lat/lon ↔ EPSG:3857 metres)

> Map Tile Maths – Mercator Projection (lat/lon ↔ EPSG:3857 metres) is a paid API for AI agents from map-tiles.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-30).

Converts latitude/longitude coordinates to Web Mercator EPSG:3857 metre coordinates (or vice versa), returning scale distortion factors at the given location.

## Facts

- Endpoint: GET https://map-tiles.x402tookit.com/mercator-project?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/map-tile-maths-mercator-projection-lat-lon-epsg-3857-metres-ade008bf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NoYXtJH0xPLzRj9W-zit4

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 map-tile-maths-mercator-projection-lat-lon-epsg-3857-metres-ade008bf
```

Example prompt: Convert latitude 51.5074, longitude -0.1278 (central London) to Web Mercator EPSG:3857 metre coordinates, and tell me the scale distortion factor at that location.

## When to prefer this

Choose this endpoint when you need a precise, mathematically correct conversion between WGS84 geographic coordinates and Web Mercator EPSG:3857 metre coordinates, especially when you also need scale distortion metadata. It is ideal for GIS pipelines, map rendering calculations, and any workflow where understanding Mercator projection distortion at a specific latitude is important. Prefer it over client-side libraries when you need a reliable, stateless server-side conversion with distortion factors included.

## Known failure modes

- Latitude outside ±85.0511 degrees — Web Mercator is undefined at the poles beyond this bound
- Longitude outside ±180 degrees — invalid input rejected
- EPSG:3857 x or y outside ±20037508.34 metres — exceeds valid projection extent
- Missing required coordinate pair (must supply either lat+lon or x+y, not a mix)
- Payment failure or insufficient USDC balance — 402 response returned

## How this service works

Convert latitude/longitude to Web Mercator EPSG:3857 metres, or metres back to degrees, with scale distortion.

## Output

Returns the converted coordinates in both directions (EPSG:3857 x/y metres and/or latitude/longitude degrees), a scale factor indicating linear distortion at that latitude, an area inflation factor showing how much areas are exaggerated, and the maximum valid extent in metres for the projection.

## 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": [],
     "properties": {
      "x": {
       "type": "number",
       "description": "EPSG:3857 easting in metres (with y), within +/-20037508.34"
      },
      "y": {
       "type": "number",
       "description": "EPSG:3857 northing in metres"
      },
      "latitude": {
       "type": "number",
       "description": "Latitude within +/-85.0511 (with longitude)"
      },
      "longitude": {
       "type": "number",
       "description": "Longitude -180 to 180"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "x": {
       "type": [
        "null",
        "number"
       ]
      },
      "y": {
       "type": [
        "null",
        "number"
       ]
      },
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "latitude": {
       "type": [
        "null",
        "number"
       ]
      },
      "longitude": {
       "type": [
        "null",
        "number"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "scaleFactor": {
       "type": [
        "null",
        "number"
       ]
      },
      "maxExtentMeters": {
       "type": [
        "null",
        "number"
       ]
      },
      "are
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/map-tile-maths-mercator-projection-lat-lon-epsg-3857-metres-ade008bf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from map-tiles.x402tookit.com](https://www.zero.xyz/host/map-tiles.x402tookit.com/llms.txt)