rocrateR: RO-Crate R Package Wrapper

The goal of rocrateR is to provide an R package for creating, manipulating and reading RO-Crates. Latest supported version 1.2 of the specification.

0. Installation

You can install the development version of rocrateR like so:

# install.packages("pak")
pak::pkg_install("ResearchObject/ro-crate-r@main")

1. First RO-Crate

The following command creates an RO-Crate Metadata descriptor (ro-crate-metadata.json). This should be stored inside the root (./) of your RO-Crate.

# library(rocrateR)
my_first_ro_crate <- rocrateR::rocrate()

This object is a list with the basic components of an RO-Crate. It can be visualised in the console with the print command:

print(my_first_ro_crate)
#> {
#>   "@context": "https://w3id.org/ro/crate/1.2/context",
#>   "@graph": [
#>     {
#>       "@id": "ro-crate-metadata.json",
#>       "@type": "CreativeWork",
#>       "about": {
#>         "@id": "./"
#>       },
#>       "conformsTo": {
#>         "@id": "https://w3id.org/ro/crate/1.2"
#>       }
#>     },
#>     {
#>       "@id": "./",
#>       "@type": "Dataset",
#>       "name": "",
#>       "description": "",
#>       "datePublished": "2025-09-20",
#>       "license": {
#>         "@id": "http://spdx.org/licenses/CC-BY-4.0"
#>       }
#>     }
#>   ]
#> }

This object can be saved to disk using the following command:

my_first_ro_crate |>
  rocrateR::write_rocrate("/path/to/ro-crate/ro-crate-metadata.json")

For example, using a temporary directory:

tmp <- file.path(tempdir(), "ro-crate-metadata.json")
my_first_ro_crate |>
  rocrateR::write_rocrate(tmp)

# load lines / flat file
readLines(tmp)
#>  [1] "{"                                                         
#>  [2] "  \"@context\": \"https://w3id.org/ro/crate/1.2/context\","
#>  [3] "  \"@graph\": ["                                           
#>  [4] "    {"                                                     
#>  [5] "      \"@id\": \"ro-crate-metadata.json\","                
#>  [6] "      \"@type\": \"CreativeWork\","                        
#>  [7] "      \"about\": {"                                        
#>  [8] "        \"@id\": \"./\""                                   
#>  [9] "      },"                                                  
#> [10] "      \"conformsTo\": {"                                   
#> [11] "        \"@id\": \"https://w3id.org/ro/crate/1.2\""        
#> [12] "      }"                                                   
#> [13] "    },"                                                    
#> [14] "    {"                                                     
#> [15] "      \"@id\": \"./\","                                    
#> [16] "      \"@type\": \"Dataset\","                             
#> [17] "      \"name\": \"\","                                     
#> [18] "      \"description\": \"\","                              
#> [19] "      \"datePublished\": \"2025-09-20\","                  
#> [20] "      \"license\": {"                                      
#> [21] "        \"@id\": \"http://spdx.org/licenses/CC-BY-4.0\""   
#> [22] "      }"                                                   
#> [23] "    }"                                                     
#> [24] "  ]"                                                       
#> [25] "}"

# delete temporal file
unlink(tmp)

2. Adding additional entities

In the previous section we created a very basic RO-Crate with the rocrateR::rocrate() function; however, you are likely to include additional entities in your RO-Crate. Entities must contain at least two components @id and @type (see https://w3id.org/ro/crate/1.2 for details).

For example, a contextual entity can be defined as follows:

# create entity for an organisation
organisation_uol <- rocrateR::entity(
  x = "https://ror.org/04xs57h96",
  type = "Organization",
  name = "University of Liverpool",
  url = "http://www.liv.ac.uk"
)

# create an entity for a person
person_rvd <- rocrateR::entity(
  x = "https://orcid.org/0000-0001-5036-8661",
  type = "Person",
  name = "Roberto Villegas-Diaz"
)

These two can be linked to each other via the @id field:

person_rvd$affiliation <- list(`@id` = organisation_uol$`@id`)

These entities can be attached to an RO-Crate using the rocrateR::add_entity() function:

my_second_ro_crate <- rocrateR::rocrate() |>
  rocrateR::add_entity(person_rvd) |>
  rocrateR::add_entity_value(id = "./", key = "author", value = list(`@id` = person_rvd$`@id`)) |>
  rocrateR::add_entity(organisation_uol)

Alternatively, the same result can be achieved with the following code:

my_second_ro_crate <- rocrateR::rocrate(person_rvd, organisation_uol) |>
  rocrateR::add_entity_value(id = "./", key = "author", value = list(`@id` = person_rvd$`@id`))

print(my_second_ro_crate)
#> {
#>   "@context": "https://w3id.org/ro/crate/1.2/context",
#>   "@graph": [
#>     {
#>       "@id": "ro-crate-metadata.json",
#>       "@type": "CreativeWork",
#>       "about": {
#>         "@id": "./"
#>       },
#>       "conformsTo": {
#>         "@id": "https://w3id.org/ro/crate/1.2"
#>       }
#>     },
#>     {
#>       "@id": "./",
#>       "@type": "Dataset",
#>       "name": "",
#>       "description": "",
#>       "datePublished": "2025-09-20",
#>       "license": {
#>         "@id": "http://spdx.org/licenses/CC-BY-4.0"
#>       },
#>       "author": {
#>         "@id": "https://orcid.org/0000-0001-5036-8661"
#>       }
#>     },
#>     {
#>       "@id": "https://orcid.org/0000-0001-5036-8661",
#>       "@type": "Person",
#>       "name": "Roberto Villegas-Diaz",
#>       "affiliation": {
#>         "@id": "https://ror.org/04xs57h96"
#>       }
#>     },
#>     {
#>       "@id": "https://ror.org/04xs57h96",
#>       "@type": "Organization",
#>       "name": "University of Liverpool",
#>       "url": "http://www.liv.ac.uk"
#>     }
#>   ]
#> }