When requesting results from Pelias, you will always get back GeoJSON results, unless something goes terribly wrong, in which case you'll get an error message.
Tip: You can go to https://tools.ietf.org/html/rfc7946 to learn more about the GeoJSON data format specification.
The top-level structure to every response looks like this:
{
"geocoding":{...},
"type":"FeatureCollection",
"features":[...],
"bbox":[...]
}
The features
property of the result is where you will find the list of results that best matched your input parameters.
Each item in this list will contain all the information needed to find it in human-readable format in the properties
block, as well as computer friendly coordinates in the geometry
property.
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
-0.125422,
51.501581
]
},
"properties": {
"id": "101750367",
"gid": "whosonfirst:locality:101750367",
"layer": "locality",
"source": "whosonfirst",
"souce_id": "101750367",
"name": "London",
"confidence": 0.949,
"country": "United Kingdom",
"country_gid": "whosonfirst:country:85633159",
"country_a": "GBR",
"macroregion": "England",
"macroregion_gid": "whosonfirst:macroregion:404227469",
"region": "City of Westminster",
"region_gid": "whosonfirst:region:85684061",
"locality": "London",
"locality_gid": "whosonfirst:locality:101750367",
"label": "London, England, United Kingdom"
},
"bbox": [
-0.4984345,
51.297207,
0.27894,
51.6843015
]
},
Additionally, /reverse queries will have a distance
parameter, which is the distance, in meters, from the query point.
All results returned from Pelias are points, and can be found in the coordinates
array. Following the GeoJSON specification, these coordinates are in longitude, latitude order.
All places in Pelias have a global identifier, known as a gid
. Each matching record returned from a /search, /autocomplete, or /reverse geocoding request has a gid
field.
The gid
consists of a layer
(such as address
or country
), an identifier for the original data source (such as openstreetmap
or openaddresses
), and an id
for the individual record corresponding to the original source identifier, where possible. This information is also available as properties on the individual results as layer
, source
, and source_id
.
- You should not create your own
gid
strings. gid
strings may not be consistent across releases.- You should not attempt to parse
gid
strings for information or store them for future use. You should only usegid
at the time when you receive the search results. One valid use for thegid
is to retrieve full details on a particular result from the /place endpoint.
The name
is a short description of the location, such as a business name, a locality name, or part of an address, depending on what is being searched for and what is returned.
For address searches, the housenumber
and street
properties are brought together under the name
property in the local standard format. This saves you from having to reassemble the address yourself, including to determine whether the numbers should be placed before or after the street name.
The label
is a human-friendly representation of the place, with the most complete details, that is ready to be displayed to an end user. Examples of a label
include a business or venue name with its locality, a complete mailing address, or a locality with region and country names. The label
field attempts to use a format that is right for the region of the result.
The confidence score is an estimation of how accurately this result matches the query.
For the /reverse endpoint, the confidence score is determined solely by its distance from the coordinate specified. Closer results get a higher score.
For the /search endpoint, it primarily takes into account how well properties in the result match what was expected from parsing the input text. For example, if the input text looks like an address, but the house number of the result doesn't match the house number that was parsed from the input text, the confidence score will be lower.
Additionally, the confidence score can optionally be biased along with other results, like test scores in a classroom might be graded on a curve. This takes into account both the property matches described above and the distance between results. This relative scoring is enabled on Pelias, but can be turned off when hosting your own Pelias instance.
Features from Who's on First and OpenStreetMap often have their own bbox
elements. This bbox
is at the same level as properties
. If present, it describes the geographic extent of the feature, such as the screen size necessary to show all of California without needing to send the precise polygon geometry. This should be treated as separate from the bbox
that describes the entire FeatureCollection
.
By default, Pelias results 10 places, unless otherwise specified. If you want a different number of results, set the size
parameter to the desired number. This example shows returning only the first result.
parameter | value |
---|---|
api_key |
get yours here |
text |
YMCA |
size |
1 |
If you want 25 results, you can build the query where size
is 25.