X-Git-Url: https://git.openstreetmap.org./nominatim.git/blobdiff_plain/17f130550ee77da527812e14dcadaea14b00e72f..4ce13f5c1fa59160a17e7db33805d48ba9a04ef5:/docs/api/Reverse.md diff --git a/docs/api/Reverse.md b/docs/api/Reverse.md index 13805fd4..6d281da8 100644 --- a/docs/api/Reverse.md +++ b/docs/api/Reverse.md @@ -1,76 +1,133 @@ # Reverse Geocoding -Reverse geocoding generates an address from a latitude and longitude or from -an OSM object. +Reverse geocoding generates an address from a coordinate given as +latitude and longitude. -## Parameters +## How it works + +The reverse geocoding API does not exactly compute the address for the +coordinate it receives. It works by finding the closest suitable OSM object +and returning its address information. This may occasionally lead to +unexpected results. + +First of all, Nominatim only includes OSM objects in +its index that are suitable for searching. Small, unnamed paths for example +are missing from the database and can therefore not be used for reverse +geocoding either. + +The other issue to be aware of is that the closest OSM object may not always +have a similar enough address to the coordinate you were requesting. For +example, in dense city areas it may belong to a completely different street. + +## Endpoint The main format of the reverse API is ``` -https://nominatim.openstreetmap.org/reverse? +https://nominatim.openstreetmap.org/reverse?lat=&lon=& ``` -There are two ways how the requested location can be specified: +where `lat` and `lon` are latitude and longitude of a coordinate in WGS84 +projection. The API returns exactly one result or an error when the coordinate +is in an area with no OSM data coverage. -* `lat=` `lon=` - A geographic location to generate an address for. The coordiantes must be - in WGS84 format. +!!! danger "Deprecation warning" + The reverse API used to allow address lookup for a single OSM object by + its OSM id for `[PHP-only]`. The use is considered deprecated. + Use the [Address Lookup API](Lookup.md) instead. -* `osm_type=[N|W|R]` `osm_id=` +!!! danger "Deprecation warning" + The API can also be used with the URL + `https://nominatim.openstreetmap.org/reverse.php`. This is now deprecated + and will be removed in future versions. - A specific OSM node(N), way(W) or relation(R) to return an address for. -In both cases exactly one object is returned. The two input parameters cannot -be used at the same time. Both accept the additional optional parameters listed -below. +## Parameters + +This section lists additional parameters to further influence the output. ### Output format -* `format=[xml|json|jsonv2|geojson|geocodejson]` +| Parameter | Value | Default | +|-----------| ----- | ------- | +| format | one of: `xml`, `json`, `jsonv2`, `geojson`, `geocodejson` | `xml` | + +See [Place Output Formats](Output.md) for details on each format. + -See [Place Output Formats](Output.md) for details on each format. (Default: html) +| Parameter | Value | Default | +|-----------| ----- | ------- | +| json_callback | function name | _unset_ | -* `json_callback=` +When given, then JSON output will be wrapped in a callback function with +the given name. See [JSONP](https://en.wikipedia.org/wiki/JSONP) for more +information. -Wrap JSON output in a callback function ([JSONP](https://en.wikipedia.org/wiki/JSONP)) i.e. `()`. Only has an effect for JSON output formats. + ### Output details -* `addressdetails=[0|1]` +| Parameter | Value | Default | +|-----------| ----- | ------- | +| addressdetails | 0 or 1 | 1 | + +When set to 1, include a breakdown of the address into elements. +The exact content of the address breakdown depends on the output format. -Include a breakdown of the address into elements. (Default: 1) +!!! tip + If you are interested in a stable classification of address categories + (suburb, city, state, etc), have a look at the `geocodejson` format. + All other formats return classifications according to OSM tagging. + There is a much larger set of categories and they are not always consistent, + which makes them very hard to work with. -* `extratags=[0|1]` +| Parameter | Value | Default | +|-----------| ----- | ------- | +| extratags | 0 or 1 | 0 | -Include additional information in the result if available, -e.g. wikipedia link, opening hours. (Default: 0) +When set to 1, the response include any additional information in the result +that is available in the database, e.g. wikipedia link, opening hours. -* `namedetails=[0|1]` +| Parameter | Value | Default | +|-----------| ----- | ------- | +| namedetails | 0 or 1 | 0 | -Include a list of alternative names in the results. These may include -language variants, references, operator and brand. (Default: 0) +When set to 1, include a full list of names for the result. These may include +language variants, older names, references and brand. ### Language of results -* `accept-language=` +| Parameter | Value | Default | +|-----------| ----- | ------- | +| accept-language | browser language string | content of "Accept-Language" HTTP header | -Preferred language order for showing search results, overrides the value -specified in the "Accept-Language" HTTP header. -Either use a standard RFC2616 accept-language string or a simple -comma-separated list of language codes. +Preferred language order for showing search results. This may either be +a simple comma-separated list of language codes or have the same format +as the ["Accept-Language" HTTP header](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept-Language). -### Result limitation +!!! tip + First-time users of Nominatim tend to be confused that they get different + results when using Nominatim in the browser versus in a command-line tool + like wget or curl. The command-line tools + usually don't send any Accept-Language header, prompting Nominatim + to show results in the local language. Browsers on the contratry always + send the currently chosen browser language. -* `zoom=[0-18]` -Level of detail required for the address. Default: 18. This is a number that corresponds -roughly to the zoom level used in map frameworks like Leaflet.js, Openlayers etc. +### Result restriction + +| Parameter | Value | Default | +|-----------| ----- | ------- | +| zoom | 0-18 | 18 | + +Level of detail required for the address. This is a number that +corresponds roughly to the zoom level used in XYZ tile sources in frameworks +like Leaflet.js, Openlayers etc. In terms of address details the zoom levels are as follows: zoom | address detail @@ -79,41 +136,81 @@ In terms of address details the zoom levels are as follows: 5 | state 8 | county 10 | city - 14 | suburb + 12 | town / borough + 13 | village / suburb + 14 | neighbourhood + 15 | any settlement 16 | major streets 17 | major and minor streets 18 | building +| Parameter | Value | Default | +|-----------| ----- | ------- | +| layer | comma-separated list of: `address`, `poi`, `railway`, `natural`, `manmade` | _unset_ (no restriction) | + +**`[Python-only]`** + +The layer filter allows to select places by themes. + +The `address` layer contains all places that make up an address: +address points with house numbers, streets, inhabited places (suburbs, villages, +cities, states etc.) and administrative boundaries. + +The `poi` layer selects all point of interest. This includes classic points +of interest like restaurants, shops, hotels but also less obvious features +like recycling bins, guideposts or benches. + +The `railway` layer includes railway infrastructure like tracks. +Note that in Nominatim's standard configuration, only very few railway +features are imported into the database. + +The `natural` layer collects feautures like rivers, lakes and mountains while +the `manmade` layer functions as a catch-all for features not covered by the +other layers. + + ### Polygon output -* `polygon_geojson=1` -* `polygon_kml=1` -* `polygon_svg=1` -* `polygon_text=1` +| Parameter | Value | Default | +|-----------| ----- | ------- | +| polygon_geojson | 0 or 1 | 0 | +| polygon_kml | 0 or 1 | 0 | +| polygon_svg | 0 or 1 | 0 | +| polygon_text | 0 or 1 | 0 | -Output geometry of results as a GeoJSON, KML, SVG or WKT. Only one of these -options can be used at a time. (Default: 0) +Add the full geometry of the place to the result output. Output formats +in GeoJSON, KML, SVG or WKT are supported. Only one of these +options can be used at a time. -* `polygon_threshold=0.0` +| Parameter | Value | Default | +|-----------| ----- | ------- | +| polygon_threshold | floating-point number | 0.0 | -Simplify the output geometry before returning. The parameter is the +When one of the polygon_* outputs is chosen, return a simplified version +of the output geometry. The parameter describes the tolerance in degrees with which the geometry may differ from the original -geometry. Topology is preserved in the result. (Default: 0.0) +geometry. Topology is preserved in the geometry. + ### Other -* `email=` +| Parameter | Value | Default | +|-----------| ----- | ------- | +| email | valid email address | _unset_ | If you are making large numbers of request please include an appropriate email -address to identify your requests. See Nominatim's [Usage Policy](https://operations.osmfoundation.org/policies/nominatim/) for more details. +address to identify your requests. See Nominatim's +[Usage Policy](https://operations.osmfoundation.org/policies/nominatim/) for more details. -* `debug=[0|1]` +| Parameter | Value | Default | +|-----------| ----- | ------- | +| debug | 0 or 1 | 0 | Output assorted developer debug information. Data on internals of Nominatim's -"Search Loop" logic, and SQL queries. The output is (rough) HTML format. -This overrides the specified machine readable format. (Default: 0) +"search loop" logic, and SQL queries. The output is HTML format. +This overrides the specified machine readable format. ## Examples @@ -149,7 +246,7 @@ This overrides the specified machine readable format. (Default: 0) "licence":"Data © OpenStreetMap contributors, ODbL 1.0. https:\/\/www.openstreetmap.org\/copyright", "osm_type":"way", "osm_id":"280940520", -"lat":"-34.4391708", + "lat":"-34.4391708", "lon":"-58.7064573", "place_rank":"26", "category":"highway",