Output options

{opencage} contains two main types of main functions distinguished by the manner in which the results are returned:

The oc_forward_df()/oc_reverse_df() functions always return a single tibble.
The oc_forward()/oc_reverse() functions return a list of various types, depending on the return value you specify. The possible return values are df_list, json_list, geojson_list and url_only.

Use of the oc_forward_df()/oc_reverse_df() functions is demonstrated in the “Introduction to opencage” and the “Customise your query” vignettes (vignette("opencage") and vignette("customise_query"), respectively) . The function arguments mentioned in these other vignettes are also generally available with oc_forward()/oc_reverse(). Here we will show the different return values available with oc_forward()/oc_reverse().

`df_list`

The default return value is df_list. It returns a list of tibbles.

stations <- c("Casey Station", "McMurdo Station")
oc_forward(stations, return = "df_list")
#> [[1]]
#> # A tibble: 1 × 17
#>   oc_confidence oc_formatted              oc_northeast_lat oc_northeast_lng oc_southwest_lat oc_southwest_lng oc_iso_3166_1_alpha_2 oc_iso_3166_1_alpha_3 oc_category oc_normalized_city oc_type oc_continent oc_country_code oc_hamlet     oc_postcode oc_lat oc_lng
#>           <int> <chr>                                <dbl>            <dbl>            <dbl>            <dbl> <chr>                 <chr>                 <chr>       <chr>              <chr>   <chr>        <chr>           <chr>         <chr>        <dbl>  <dbl>
#> 1             7 Casey Station, Antarctica            -66.3             111.            -66.3             111. AQ                    ATA                   place       Casey Station      hamlet  Antarctica   aq              Casey Station 7151         -66.3   111.
#> 
#> [[2]]
#> # A tibble: 1 × 16
#>   oc_confidence oc_formatted                oc_northeast_lat oc_northeast_lng oc_southwest_lat oc_southwest_lng oc_iso_3166_1_alpha_2 oc_iso_3166_1_alpha_3 oc_category oc_normalized_city oc_type oc_continent oc_country_code oc_town         oc_lat oc_lng
#>           <int> <chr>                                  <dbl>            <dbl>            <dbl>            <dbl> <chr>                 <chr>                 <chr>       <chr>              <chr>   <chr>        <chr>           <chr>            <dbl>  <dbl>
#> 1             7 McMurdo Station, Antarctica            -77.8             167.            -77.9             167. AQ                    ATA                   place       McMurdo Station    city    Antarctica   aq              McMurdo Station  -77.8   167.

The df_list type drives the oc_forward_df()/oc_reverse_df() functions. You can use the df_list output in a dplyr::mutate() chain to replicate the functionality of oc_forward_df():

library(dplyr, warn.conflicts = FALSE)

oc_data <-
  tibble(place = stations) %>%
  mutate(oc_result = oc_forward(place))

oc_data
#> # A tibble: 2 × 2
#>   place           oc_result        
#>   <chr>           <list>           
#> 1 Casey Station   <tibble [1 × 17]>
#> 2 McMurdo Station <tibble [1 × 16]>

This creates a list column oc_result, which can be easily unnested with tidyr::unnest():

library(tidyr, warn.conflicts = FALSE)

oc_data %>% unnest(oc_result)
#> # A tibble: 2 × 19
#>   place           oc_confidence oc_formatted             oc_northeast_lat oc_northeast_lng oc_southwest_lat oc_southwest_lng oc_iso_3166_1_alpha_2 oc_iso_3166_1_alpha_3 oc_category oc_normalized_city oc_type oc_continent oc_country_code oc_hamlet oc_postcode oc_lat oc_lng oc_town
#>   <chr>                   <int> <chr>                               <dbl>            <dbl>            <dbl>            <dbl> <chr>                 <chr>                 <chr>       <chr>              <chr>   <chr>        <chr>           <chr>     <chr>        <dbl>  <dbl> <chr>  
#> 1 Casey Station               7 Casey Station, Antarcti…            -66.3             111.            -66.3             111. AQ                    ATA                   place       Casey Station      hamlet  Antarctica   aq              Casey St… 7151         -66.3   111. <NA>   
#> 2 McMurdo Station             7 McMurdo Station, Antarc…            -77.8             167.            -77.9             167. AQ                    ATA                   place       McMurdo Station    city    Antarctica   aq              <NA>      <NA>         -77.8   167. McMurd…

`json_list`

OpenCage’s main output format is JSON. When you specify json_list as the return type, you get the JSON as an R list().

oc_forward("Casey Station", return = "json_list")
#> [[1]]
#> [[1]]$documentation
#> [1] "https://opencagedata.com/api"
#> 
#> [[1]]$licenses
#> [[1]]$licenses[[1]]
#> [[1]]$licenses[[1]]$name
#> [1] "see attribution guide"
#> 
#> [[1]]$licenses[[1]]$url
#> [1] "https://opencagedata.com/credits"
#> 
#> 
#> 
#> [[1]]$results
#> [[1]]$results[[1]]
#> [[1]]$results[[1]]$bounds
#> [[1]]$results[[1]]$bounds$northeast
#> [[1]]$results[[1]]$bounds$northeast$lat
#> [1] -66.26209
#> 
#> [[1]]$results[[1]]$bounds$northeast$lng
#> [1] 110.5441
#> 
#> 
#> [[1]]$results[[1]]$bounds$southwest
#> [[1]]$results[[1]]$bounds$southwest$lat
#> [1] -66.30209
#> 
#> [[1]]$results[[1]]$bounds$southwest$lng
#> [1] 110.5041
#> 
#> 
#> 
#> [[1]]$results[[1]]$components
#> [[1]]$results[[1]]$components$`ISO_3166-1_alpha-2`
#> [1] "AQ"
#> 
#> [[1]]$results[[1]]$components$`ISO_3166-1_alpha-3`
#> [1] "ATA"
#> 
#> [[1]]$results[[1]]$components$`_category`
#> [1] "place"
#> 
#> [[1]]$results[[1]]$components$`_normalized_city`
#> [1] "Casey Station"
#> 
#> [[1]]$results[[1]]$components$`_type`
#> [1] "hamlet"
#> 
#> [[1]]$results[[1]]$components$continent
#> [1] "Antarctica"
#> 
#> [[1]]$results[[1]]$components$country_code
#> [1] "aq"
#> 
#> [[1]]$results[[1]]$components$hamlet
#> [1] "Casey Station"
#> 
#> [[1]]$results[[1]]$components$postcode
#> [1] "7151"
#> 
#> 
#> [[1]]$results[[1]]$confidence
#> [1] 7
#> 
#> [[1]]$results[[1]]$formatted
#> [1] "Casey Station, Antarctica"
#> 
#> [[1]]$results[[1]]$geometry
#> [[1]]$results[[1]]$geometry$lat
#> [1] -66.28209
#> 
#> [[1]]$results[[1]]$geometry$lng
#> [1] 110.5241
#> 
#> 
#> 
#> 
#> [[1]]$status
#> [[1]]$status$code
#> [1] 200
#> 
#> [[1]]$status$message
#> [1] "OK"
#> 
#> 
#> [[1]]$stay_informed
#> [[1]]$stay_informed$blog
#> [1] "https://blog.opencagedata.com"
#> 
#> [[1]]$stay_informed$mastodon
#> [1] "https://en.osm.town/@opencage"
#> 
#> 
#> [[1]]$thanks
#> [1] "For using an OpenCage API"
#> 
#> [[1]]$timestamp
#> [[1]]$timestamp$created_http
#> [1] "Wed, 07 Oct 2026 21:01:07 GMT"
#> 
#> [[1]]$timestamp$created_unix
#> [1] 1791406867
#> 
#> 
#> [[1]]$total_results
#> [1] 1

`geojson_list`

When you choose geojson_list as the return type, the geocoder response will be returned as GeoJSON specified as an R list().

gjsn_lst <- oc_forward("Casey Station", return = "geojson_list")
gjsn_lst
#> [[1]]
#> $documentation
#> [1] "https://opencagedata.com/api"
#> 
#> $features
#> $features[[1]]
#> $features[[1]]$geometry
#> $features[[1]]$geometry$coordinates
#> $features[[1]]$geometry$coordinates[[1]]
#> [1] 110.5241
#> 
#> $features[[1]]$geometry$coordinates[[2]]
#> [1] -66.28209
#> 
#> 
#> $features[[1]]$geometry$type
#> [1] "Point"
#> 
#> 
#> $features[[1]]$properties
#> $features[[1]]$properties$bounds
#> $features[[1]]$properties$bounds$northeast
#> $features[[1]]$properties$bounds$northeast$lat
#> [1] -66.26209
#> 
#> $features[[1]]$properties$bounds$northeast$lng
#> [1] 110.5441
#> 
#> 
#> $features[[1]]$properties$bounds$southwest
#> $features[[1]]$properties$bounds$southwest$lat
#> [1] -66.30209
#> 
#> $features[[1]]$properties$bounds$southwest$lng
#> [1] 110.5041
#> 
#> 
#> 
#> $features[[1]]$properties$components
#> $features[[1]]$properties$components$`ISO_3166-1_alpha-2`
#> [1] "AQ"
#> 
#> $features[[1]]$properties$components$`ISO_3166-1_alpha-3`
#> [1] "ATA"
#> 
#> $features[[1]]$properties$components$`_category`
#> [1] "place"
#> 
#> $features[[1]]$properties$components$`_normalized_city`
#> [1] "Casey Station"
#> 
#> $features[[1]]$properties$components$`_type`
#> [1] "hamlet"
#> 
#> $features[[1]]$properties$components$continent
#> [1] "Antarctica"
#> 
#> $features[[1]]$properties$components$country_code
#> [1] "aq"
#> 
#> $features[[1]]$properties$components$hamlet
#> [1] "Casey Station"
#> 
#> $features[[1]]$properties$components$postcode
#> [1] "7151"
#> 
#> 
#> $features[[1]]$properties$confidence
#> [1] 7
#> 
#> $features[[1]]$properties$formatted
#> [1] "Casey Station, Antarctica"
#> 
#> 
#> $features[[1]]$type
#> [1] "Feature"
#> 
#> 
#> 
#> $licenses
#> $licenses[[1]]
#> $licenses[[1]]$name
#> [1] "see attribution guide"
#> 
#> $licenses[[1]]$url
#> [1] "https://opencagedata.com/credits"
#> 
#> 
#> 
#> $rate
#> named list()
#> 
#> $status
#> $status$code
#> [1] 200
#> 
#> $status$message
#> [1] "OK"
#> 
#> 
#> $stay_informed
#> $stay_informed$blog
#> [1] "https://blog.opencagedata.com"
#> 
#> $stay_informed$mastodon
#> [1] "https://en.osm.town/@opencage"
#> 
#> 
#> $thanks
#> [1] "For using an OpenCage API"
#> 
#> $timestamp
#> $timestamp$created_http
#> [1] "Wed, 07 Oct 2026 21:01:10 GMT"
#> 
#> $timestamp$created_unix
#> [1] 1791406870
#> 
#> 
#> $total_results
#> [1] 1
#> 
#> $type
#> [1] "FeatureCollection"
#> 
#> attr(,"class")
#> [1] "geo_list"

In fact, {opencage} returns a list of results in geo_list format, which should be compatible with the {geojsonio} package.

class(gjsn_lst[[1]])
#> [1] "geo_list"

`url_only`

url_only returns the OpenCage URL for debugging purposes.

oc_forward("Casey Station", return = "url_only")
#> [[1]]
#> [1] "https://api.opencagedata.com/geocode/v1/json?q=Casey%20Station&limit=10&no_annotations=1&roadinfo=0&no_dedupe=0&no_record=1&abbrv=0&address_only=0&add_request=0&key=OPENCAGE_KEY"

Your OpenCage API key is masked with the OPENCAGE_KEY string, by default. If you really want {opencage} to display your API key with the URL, set the show_key argument in oc_config() to TRUE.

oc_config(show_key = TRUE)

Note that the API key will only be returned with the URL in base::interactive() mode.

`xml`

{opencage} does not support the XML response type at the moment. Please file an issue or a pull-request if you have a use-case that requires this.

Return query text

oc_forward() and oc_reverse() have an add_request argument, indicating whether the request is returned again with the results. If the return value is a df_list, the placename or latitude,longitude is added as a column to the results without a roundtrip to the API. json_list results will contain all request parameters as returned by the API. This would normally include your OpenCage API key, but {opencage} masks the key and replaces it with the OPENCAGE_KEY string in the output. add_request is currently ignored by OpenCage for GeoJSON results.