Data Access API

The Data Access API provides programmatic download access to the files stored under Dataverse. More advanced features of the Access API include format-specific transformations (thumbnail generation/resizing for images; converting tabular data into alternative file formats) and access to the data-level metadata that describes the contents of the tabular files.

Basic File Access

Basic access URI:

/api/access/datafile/$id

Note

Files can be accessed using persistent identifiers. This is done by passing the constant :persistentId where the numeric id of the file is expected, and then passing the actual persistent id as a query parameter with the name persistentId.

Example: Getting the file whose DOI is 10.5072/FK2/J8SJZB

GET http://$SERVER/api/access/datafile/:persistentId/?persistentId=doi:10.5072/FK2/J8SJZB

Parameters:

format

the following parameter values are supported (for tabular data files only):

Value

Description

original

“Saved Original”, the proprietary (SPSS, Stata, R, etc.) file from which the tabular data was ingested;

RData

Tabular data as an R Data frame (generated; unless the “original” file was in R);

prep

“Pre-processed data”, in JSON.

subset

Column-wise subsetting. You must also supply a comma separated list of variables in the “variables” query parameter. In this example, 123 and 127 are the database ids of data variables that belong to the data file with the id 6: curl 'http://localhost:8080/api/access/datafile/6?format=subset&variables=123,127'.


noVarHeader

(supported for tabular data files only; ignored for all other file types)

Value

Description

true|1

Tab-delimited data file, without the variable name header (added to tab. files by default)


imageThumb

the following parameter values are supported (for image and pdf files only):

Value

Description

true

Generates a thumbnail image, by rescaling to the default thumbnail size (64 pixels)

N

Rescales the image to N pixels.

Multiple File (“bundle”) download

/api/access/datafiles/$id1,$id2,...$idN

Returns the files listed, zipped.

Note

If the request can only be completed partially - if only some of the requested files can be served (because of the permissions and/or size restrictions), the file MANIFEST.TXT included in the zipped bundle will have entries specifying the reasons the missing files could not be downloaded. IN THE FUTURE the API will return a 207 status code to indicate that the result was a partial success. (As of writing this - v.4.11 - this hasn’t been implemented yet)

Note

If any of the datafiles have the DirectoryLabel attributes in the corresponding FileMetadata entries, these will be added as folders to the Zip archive, and the files will be placed in them accordingly.

Parameters:

format the following parameter values are supported (for tabular data files only):

Value

Description

original

“Saved Original”, the proprietary (SPSS, Stata, R, etc.) file from which the tabular data was ingested;

“All Formats” bundled download for Tabular Files.

/api/access/datafile/bundle/$id

This is a convenience packaging method available for tabular data files. It returns a zipped bundle that contains the data in the following formats:

  • Tab-delimited;

  • “Saved Original”, the proprietary (SPSS, Stata, R, etc.) file from which the tabular data was ingested;

  • Generated R Data frame (unless the “original” was already in R);

  • Data (Variable) metadata record, in DDI XML;

  • File citation, in Endnote and RIS formats.

Parameters:

none.

Data Variable Metadata Access

These methods are only available for tabular data files. (i.e., data files with associated data table and variable objects).

/api/access/datafile/$id/metadata/ddi

In its basic form this command returns a DDI fragment that describes the file and the data variables in it.

The DDI returned will only have two top-level sections:

  • a single fileDscr, with the basic file information plus the numbers of variables and observations and the UNF of the file.

  • a single dataDscr section, with one var section for each variable.

Example:

http://localhost:8080/api/access/datafile/6/metadata/ddi

<codeBook version="2.0">
   <fileDscr ID="f6">
      <fileTxt>
         <fileName>_73084.tab</fileName>
         <dimensns>
            <caseQnty>3</caseQnty>
            <varQnty>2</varQnty>
         </dimensns>
         <fileType>text/tab-separated-values</fileType>
      </fileTxt>
      <notes level="file" type="VDC:UNF" subject="Universal Numeric Fingerprint">UNF:6:zChnyI3fjwNP+6qW0VryVQ==</notes>
   </fileDscr>
   <dataDscr>
      <var ID="v1" name="id" intrvl="discrete">
         <location fileid="f6"/>
         <labl level="variable">Personen-ID</labl>
         <sumStat type="mean">2.0</sumStat>
         <sumStat type="mode">.</sumStat>
         <sumStat type="medn">2.0</sumStat>
         <sumStat type="stdev">1.0</sumStat>
         <sumStat type="min">1.0</sumStat>
         <sumStat type="vald">3.0</sumStat>
         <sumStat type="invd">0.0</sumStat>
         <sumStat type="max">3.0</sumStat>
         <varFormat type="numeric"/>
         <notes subject="Universal Numeric Fingerprint" level="variable" type="VDC:UNF">UNF:6:AvELPR5QTaBbnq6S22Msow==</notes>
      </var>
      <var ID="v3" name="sex" intrvl="discrete">
         <location fileid="f6"/>
         <labl level="variable">Geschlecht</labl>
         <sumStat type="mean">1.3333333333333333</sumStat>
         <sumStat type="max">2.0</sumStat>
         <sumStat type="vald">3.0</sumStat>
         <sumStat type="mode">.</sumStat>
         <sumStat type="stdev">0.5773502691896257</sumStat>
         <sumStat type="invd">0.0</sumStat>
         <sumStat type="medn">1.0</sumStat>
         <sumStat type="min">1.0</sumStat>
         <catgry>
            <catValu>1</catValu>
            <labl level="category">Mann</labl>
         </catgry>
         <catgry>
            <catValu>2</catValu>
            <labl level="category">Frau</labl>
         </catgry>
         <varFormat type="numeric"/>
         <notes subject="Universal Numeric Fingerprint" level="variable" type="VDC:UNF">UNF:6:XqQaMwOA63taX1YyBzTZYQ==</notes>
      </var>
   </dataDscr>
</codeBook>

More information on DDI is available in the Tabular Data, Representation, Storage and Ingest section of the User Guide.

Advanced options/Parameters:

It is possible to request only specific subsets of, rather than the full file-level DDI record. This can be a useful optimization, in cases such as when an application needs to look up a single variable; especially with data files with large numbers of variables. See subset param in the Parameters: section.

Preprocessed Data

/api/access/datafile/$id/metadata/preprocessed

This method provides the “preprocessed data” - a summary record that describes the values of the data vectors in the tabular file, in JSON. These metadata values are used by TwoRavens, the companion data exploration utility of the Dataverse application. Please note that this format might change in the future.

Authentication and Authorization

Data Access API supports both session- and API key-based authentication.

If a session is available, and it is already associated with an authenticated user, it will be used for access authorization. If not, or if the user in question is not authorized to access the requested object, an attempt will be made to authorize based on an API key, if supplied. All of the API endpoints presented in this document support the key parameter key=... as well as the newer X-Dataverse-key header. For more details, see “Authentication” in the Introduction section.

Access Requests and Processing

All of the following endpoints take the persistent identifier as a parameter in place of ‘id’.

Request Access:

/api/access/datafile/$id/requestAccess

This method requests access to the datafile whose id is passed on the behalf of an authenticated user whose key is passed. Note that not all datasets allow access requests to restricted files.

A curl example using an id:

curl -H "X-Dataverse-key:$API_TOKEN" -X PUT http://$SERVER/api/access/datafile/{id}/requestAccess

Grant File Access:

/api/access/datafile/{id}/grantAccess/{identifier}

This method grants access to the datafile whose id is passed on the behalf of an authenticated user whose user identifier is passed with an @ prefix. The key of a user who can manage permissions of the datafile is required to use this method.

A curl example using an id:

curl -H "X-Dataverse-key:$API_TOKEN" -X PUT http://$SERVER/api/access/datafile/{id}/grantAccess/{@userIdentifier}

Reject File Access:

/api/access/datafile/{id}/rejectAccess/{identifier}

This method rejects the access request to the datafile whose id is passed on the behalf of an authenticated user whose user identifier is passed with an @ prefix. The key of a user who can manage permissions of the datafile is required to use this method.

A curl example using an id:

curl -H "X-Dataverse-key:$API_TOKEN" -X PUT http://$SERVER/api/access/datafile/{id}/rejectAccess/{@userIdentifier}

Revoke File Access:

/api/access/datafile/{id}/revokeAccess/{identifier}

This method revokes previously granted access to the datafile whose id is passed on the behalf of an authenticated user whose user identifier is passed with an @ prefix. The key of a user who can manage permissions of the datafile is required to use this method.

A curl example using an id:

curl -H "X-Dataverse-key:$API_TOKEN" -X DELETE http://$SERVER/api/access/datafile/{id}/revokeAccess/{@userIdentifier}

List File Access Requests:

/api/access/datafile/{id}/listRequests

This method returns a list of Authenticated Users who have requested access to the datafile whose id is passed. The key of a user who can manage permissions of the datafile is required to use this method.

A curl example using an id:

curl -H "X-Dataverse-key:$API_TOKEN" -X GET http://$SERVER/api/access/datafile/{id}/listRequests