Items

The items endpoint returns the features in a collection as a GeoJSON FeatureCollection. This is the workhorse of the OGC API, it is what GIS clients call to draw a layer.

Requires an organization API key with the GIS_ACCESS addon in the X-API-Key header, plus a license for the dataset. Each items request costs 10 credits; see Rate limits and credits. See Authentication.

Get features

curl -H "X-API-Key: tlb_prod_..." \
  "https://api.topolab.nl/v1/ogc/collections/transport_infrastructure_bushaltes/items?limit=2"

{
  "type": "FeatureCollection",
  "numberMatched": 51532,
  "numberReturned": 2,
  "features": [
    {
      "type": "Feature",
      "id": "transport_infrastructure_bushaltes.1",
      "geometry": {
        "type": "Point",
        "coordinates": [4.8952, 52.3702]
      },
      "properties": {
        "name": "Amsterdam, Centraal Station",
        "category": "bus_stop",
        "city": "Amsterdam",
        "country": "nl",
        "postal_code": "1012 AB"
      }
    },
    {
      "type": "Feature",
      "id": "transport_infrastructure_bushaltes.2",
      "geometry": {
        "type": "Point",
        "coordinates": [4.4777, 51.9244]
      },
      "properties": {
        "name": "Rotterdam, Centraal Station",
        "category": "bus_stop",
        "city": "Rotterdam",
        "country": "nl",
        "postal_code": "3013 AP"
      }
    }
  ],
  "links": [
    {
      "rel": "self",
      "type": "application/geo+json",
      "href": "https://api.topolab.nl/v1/ogc/collections/transport_infrastructure_bushaltes/items?limit=2&offset=0"
    },
    {
      "rel": "next",
      "type": "application/geo+json",
      "href": "https://api.topolab.nl/v1/ogc/collections/transport_infrastructure_bushaltes/items?limit=2&offset=2"
    }
  ]
}

Coordinates are WGS84 (EPSG:4326) in GeoJSON longitude-first order: [longitude, latitude].

Reading the response

• numberMatched, the total number of features that match the request, across all pages.
• numberReturned, how many features are in this page (at most limit).
• links, navigation. A next link is present when more features remain; follow it to get the next page. The last page has no next link. The same next pointer is also returned as an HTTP Link: <...>; rel="next" response header, so you can page from the headers without parsing the body.

Paging with limit and offset

Parameter	Default	Max	Meaning
limit	100	1000	Number of features to return in this page.
offset	0	—	Number of features to skip before returning results.

Page through a large collection by incrementing offset by limit, or simply by following each response's next link until none is returned.

# First page (features 0–99)
curl -H "X-API-Key: tlb_prod_..." \
  "https://api.topolab.nl/v1/ogc/collections/transport_infrastructure_bushaltes/items?limit=100&offset=0"

# Second page (features 100–199)
curl -H "X-API-Key: tlb_prod_..." \
  "https://api.topolab.nl/v1/ogc/collections/transport_infrastructure_bushaltes/items?limit=100&offset=100"

Requesting a limit above 1000 is capped at 1000. Each page costs 10 credits, so paging a large collection adds up; for bulk extraction of an entire dataset in one call, a full file download over the Datasets API is often simpler and cheaper than paging.

Errors

Status	Meaning
401	Missing or invalid API key (API key is required).
403	Key is valid but the organization lacks the GIS_ACCESS addon.
404	Unknown collectionId, or a dataset your organization is not licensed for. The two cases return the same 404.
429	Rate limit exceeded.

Next

• bbox and filtering, narrow results by area, category, city, or country.
• Single feature, fetch one feature by id.