Gelderland Province geoportal (ArcGIS REST)

Base URL

https://geoportaal.gelderland.nl/gisserver/rest/services

Endpoints 7

• GET?f=jsonDirectory: version, folders and services (name + type).
• GET/{map}?f=jsonServices in one folder.
• GET/{dienst}/MapServer?f=jsonService: layers and tables (id, name, group layer or not), maxRecordCount, capabilities, projection, description.
• GET/{dienst}/MapServer/{laag}?f=jsonLayer: fields (name, type, alias, length), geometry type, maxRecordCount, supportedQueryFormats and advancedQueryCapabilities (pagination, statistics, orderBy, distinct).
• GET/{dienst}/MapServer/{laag}/queryQuery features with a where clause or spatial filter; also count (returnCountOnly) and group (outStatistics). Response in JSON, GeoJSON or PBF.
• GET/{dienst}/MapServer/legend?f=jsonLegend per layer: labels and symbols (PNG as base64).
• GET/{dienst}/MapServer/export?bbox=…&bboxSR=4326&size=600,400&format=png&f=imageMap image as PNG for a rectangle; with f=json you get a link to the image. Without bbox: error 'bbox must be specified'.

The APIs of this source 1 · from the provider's documentation from the description

Filtering platform

SQL-like where clause on the layer's fields, plus an optional spatial filter (geometry). Group and count with outStatistics.

Parameters 13

Fields of the example layer 14 · Infra/Infra/MapServer/229 (119.275 locaties, 2017–2024)

Limits and pitfalls

• At most 20.000 (deze laag; elders meestal 2.000, soms 1.000 of meer) features per response (the layer's maxRecordCount; varies per layer, see /{layer}?f=json). If there are more, the response has exceededTransferLimit: true: fetch the rest with resultOffset and resultRecordCount. tested
• No key and no documented rate limit. Take it easy (a few requests per second) and prefer statistics or counts over fetching all features. experience
• Errors come back with HTTP 200 and a JSON object {"error": {"code": 400, …}} ('Failed to execute query.' for an unknown field in where). Always check for an error field, not just the status code. tested
• The MapServers here have no WMS extension (supportedExtensions empty; /WMSServer returns HTTP 400). Map images only via export. tested
• 161 services in the Hosted folder are tile services (TilesOnly): no fields and no query. experience
• The REST server gives no dates. The Gelderland Portal does: /portaal/sharing/rest/search gives per item a title ('Infra- Ongevallen registratie'), description, modified (newest 13 Oct 2026) and the layer url. tested
• Field names are short (ong_let, wpsnaamnen), but the aliases in /{layer}?f=json are readable ('Aantal ongevallen met letsel'). tested
• Connections to this server sometimes failed in earlier harvests with a timeout or SSL error; retry. experience
• Group layers (with subLayerIds) have no query; query the leaf layers below them. Raster layers have no fields and no count. platform

Try it HTTP 200 · 732 ms · 16 Oct

https://geoportaal.gelderland.nl/gisserver/rest/services/Infra/Infra/MapServer/229/query?where=1%3D1&outStatistics=[{"statisticType"%3A"sum"%2C"onStatisticField"%3A"ong_tot"%2C"outStatisticFieldName"%3A"n"}]&groupByFieldsForStatistics=jaar&orderByFields=jaar&f=json

{
  "displayFieldName": "",
  "fieldAliases": {
    "jaar": "jaar",
    "n": "n"
  },
  "fields": [
    {
      "name": "jaar",
      "type": "esriFieldTypeString",
      "alias": "jaar",
      "length": 7
    },
    {
      "name": "n",
      "type": "esriFieldTypeBigInteger",
      "alias": "n"
    }
  ],
  "features": [
    {
      "attributes": {
        "jaar": "2017",
        "n": 15957
      }
    },
    {
      "attributes": {
        "jaar": "2018",
        "n": 15956
      }
    }
  ]
}

Shortened response, saved at harvest time. Click the URL for the real, current response.