Guide - ArcGIS REST API

Overview

The ArcGIS REST API provides access to Esri’s ArcGIS Server, ArcGIS Online, and ArcGIS Enterprise services. This guide covers common endpoints and usage patterns for querying geospatial data.

Base URL Structure

https://<host>/<instance>/rest/services/<folder>/<serviceName>/<serviceType>

Examples:

• FEMA: https://hazards.fema.gov/arcgis/rest/services
• ArcGIS Online: https://services.arcgis.com/<orgId>/arcgis/rest/services

Server Info Endpoint

/info

Returns server metadata and authentication information.

Request:

GET https://hazards.fema.gov/arcgis/rest/info?f=json HTTP/1.1
Host: hazards.fema.gov

Response:

{
  "currentVersion": 11.1,
  "fullVersion": "11.1.0",
  "soapUrl": "https://hazards.fema.gov/arcgis/services",
  "secureSoapUrl": null,
  "authInfo": {
    "isTokenBasedSecurity": true,
    "tokenServicesUrl": "https://hazards.fema.gov/arcgis/tokens/",
    "shortLivedTokenValidity": 60
  }
}

/info/healthCheck

Returns service health status.

GET https://hazards.fema.gov/arcgis/rest/info/healthCheck?f=pjson

Service Types

Type	URL Suffix	Description
MapServer	/MapServer	Map service (rendering + query)
FeatureServer	/FeatureServer	Feature service (CRUD operations)
ImageServer	/ImageServer	Raster imagery service
GeocodeServer	/GeocodeServer	Geocoding service
GeometryServer	/GeometryServer	Geometry operations

Querying Features

MapServer/FeatureServer Query

Endpoint: /<ServiceName>/MapServer/<LayerID>/query

Common Parameters:

Parameter	Description	Example
where	SQL where clause	STATE='CA'
geometry	Spatial filter geometry	{"x":-122,"y":37}
geometryType	Type of geometry	esriGeometryPoint
spatialRel	Spatial relationship	esriSpatialRelIntersects
outFields	Fields to return	* or OBJECTID,NAME
returnGeometry	Return shapes	true or false
outSR	Output spatial reference	4326
f	Output format	json, geojson, pjson

Example - Query FEMA Flood Zones:

GET https://hazards.fema.gov/gis/nfhl/rest/services/public/NFHL/MapServer/28/query
?where=1=1
&outFields=*
&geometry=-122.4,37.8,-122.3,37.9
&geometryType=esriGeometryEnvelope
&spatialRel=esriSpatialRelIntersects
&returnGeometry=true
&outSR=4326
&f=geojson

Spatial Relationships

Value	Description
esriSpatialRelIntersects	Geometry intersects
esriSpatialRelContains	Geometry contains
esriSpatialRelWithin	Geometry within
esriSpatialRelTouches	Geometry touches
esriSpatialRelOverlaps	Geometry overlaps

Geometry Types

Value	Description
esriGeometryPoint	Single point
esriGeometryPolyline	Line geometry
esriGeometryPolygon	Polygon geometry
esriGeometryEnvelope	Bounding box

Authentication

Token-Based Authentication

1. Request token from token service:

POST https://server/arcgis/tokens/generateToken
Content-Type: application/x-www-form-urlencoded
 
username=myuser&password=mypassword&f=json

2. Include token in requests:

?token=<your_token>&f=json

API Keys (ArcGIS Online)

For ArcGIS Online, use an API key in the header or query parameter:

?token=<api_key>

R Integration

Using httr2 for ArcGIS REST API queries:

library(httr2)
library(sf)
 
query_arcgis <- function(base_url, layer_id, where = "1=1", bbox = NULL) {
  url <- paste0(base_url, "/", layer_id, "/query")
  
  req <- httr2::request(url) |>
    httr2::req_url_query(
      where = where,
      outFields = "*",
      returnGeometry = "true",
      outSR = 4326,
      f = "geojson"
    )
  
  if (!is.null(bbox)) {
    req <- req |>
      httr2::req_url_query(
        geometry = paste(bbox, collapse = ","),
        geometryType = "esriGeometryEnvelope",
        spatialRel = "esriSpatialRelIntersects"
      )
  }
  
  resp <- req |> httr2::req_perform()
  geojson <- httr2::resp_body_json(resp)
  
  sf::st_read(jsonlite::toJSON(geojson, auto_unbox = TRUE), quiet = TRUE)
}

Common Services

Service	Base URL
FEMA NFHL	https://hazards.fema.gov/gis/nfhl/rest/services/public/NFHL/MapServer
Census TIGERweb	https://tigerweb.geo.census.gov/arcgis/rest/services
USGS National Map	https://apps.nationalmap.gov/arcgis/rest/services

Notes

• Always check /info first to understand server capabilities
• Use f=geojson for direct import into GIS tools
• For large queries, use pagination with resultOffset and resultRecordCount
• Consider using the arcgislayers R package for simplified access

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Appendix

Created: 2024-12-22 | Modified: 2024-12-22

See Also

• MOC - Geospatial
• List - Property Data Platforms
• Federal Emergency Management Agency (FEMA)

Backlinks

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