APIs

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TerrainX uses two external APIs. Both are free with no authentication required.

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OpenFreeMap

Purpose: Serves the actual map tile data (roads, buildings, water, etc.)

Request 1 — TileJSON manifest

Called once on map load to get the tile URL template and metadata.

GET https://tiles.openfreemap.org/planet

Response:

{
  "tilejson": "3.0.0",
  "tiles": ["https://tiles.openfreemap.org/planet/{z}/{x}/{y}"],
  "minzoom": 0,
  "maxzoom": 14,
  "bounds": [-180, -85.05, 180, 85.05],
  "attribution": "© OpenMapTiles © OpenStreetMap"
}

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Request 2 — Vector tiles

Called many times as the user pans and zooms.

GET https://tiles.openfreemap.org/planet/{z}/{x}/{y}

Param	Description
z	Zoom level (0–14)
x	Tile column
y	Tile row

Response: Binary .pbf (Protocol Buffer) — decoded by MapLibre internally.

Auth	None
Rate limit	Generous — fine for dev/test
Attribution required	Yes — © OpenMapTiles © OpenStreetMap

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Nominatim

Purpose: Geocoding — converts a search string into coordinates. Used only by [[components/SearchBox|<SearchBox />]].

GET https://nominatim.openstreetmap.org/search

Query params:

Param	Value	Description
q	"New Delhi"	Search string
format	"json"	Response format
limit	5	Max number of results

Example:

GET https://nominatim.openstreetmap.org/search?q=New+Delhi&format=json&limit=5

Response:

[
  {
    "display_name": "New Delhi, Delhi, India",
    "lat": "28.6139391",
    "lon": "77.2090212"
  }
]

Auth	None
Rate limit	1 request/second
Required header	User-Agent: TerrainX/1.0
Production use	Not recommended — dev/test only

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Summary

API	Called by	Auth	Rate limit
OpenFreeMap tiles	<Map /> (via MapLibre)	None	Generous
Nominatim search	<SearchBox />	None	1 req/sec