Data Access API

The Data Access API provides programmatic download access to the files stored in a Dataverse installation. 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.

Contents:

Downloading All Files in a Dataset

The “download by dataset” API downloads as many files as possible from a dataset as a zipped bundle.

By default, tabular files are downloaded in their “archival” form (tab-separated values). To download the original files (Stata, for example), add format=original as a query parameter.

There are a number of reasons why not all of the files can be downloaded:

Some of the files are restricted and your API token doesn’t have access (you will still get the unrestricted files).
The Dataverse installation has limited how large the zip bundle can be.

In the curl example below, the flags -O and J are used. When there are no errors, this has the effect of saving the file as “dataverse_files.zip” (just like the web interface). The flags force errors to be downloaded as a file.

Please note that in addition to the files from dataset, an additional file call “MANIFEST.TXT” will be included in the zipped bundle. It has additional information about the files.

There are two forms of the “download by dataset” API, a basic form and one that supports dataset versions.

Basic Download By Dataset

The basic form downloads files from the latest accessible version of the dataset. If you are not using an API token, this means the most recently published version. If you are using an API token with full access to the dataset, this means the draft version or the most recently published version if no draft exists.

A curl example using a DOI (no version):

export API_TOKEN=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
export SERVER_URL=https://demo.dataverse.org
export PERSISTENT_ID=doi:10.70122/FK2/N2XGBJ

curl -L -O -J -H "X-Dataverse-key:$API_TOKEN" $SERVER_URL/api/access/dataset/:persistentId/?persistentId=$PERSISTENT_ID

The fully expanded example above (without environment variables) looks like this:

curl -L -O -J -H X-Dataverse-key:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx https://demo.dataverse.org/api/access/dataset/:persistentId/?persistentId=doi:10.70122/FK2/N2XGBJ

Download By Dataset By Version

The second form of the “download by dataset” API allows you to specify which version you’d like to download files from. As with the datasets API endpoints described in the Native API section, the following identifiers can be used.

:draft the draft version, if any
:latest either a draft (if exists) or the latest published version.
:latest-published the latest published version
x.y a specific version, where x is the major version number and y is the minor version number.
x same as x.0

A curl example using a DOI (with version):

export API_TOKEN=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
export SERVER_URL=https://demo.dataverse.org
export PERSISTENT_ID=doi:10.70122/FK2/N2XGBJ
export VERSION=2.0

curl -O -J -H "X-Dataverse-key:$API_TOKEN" $SERVER_URL/api/access/dataset/:persistentId/versions/$VERSION?persistentId=$PERSISTENT_ID

The fully expanded example above (without environment variables) looks like this:

curl -O -J -H X-Dataverse-key:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx https://demo.dataverse.org/api/access/dataset/:persistentId/versions/2.0?persistentId=doi:10.70122/FK2/N2XGBJ

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 wide).
`N`	Rescales the image to `N` pixels wide. `imageThumb=true` and `imageThumb=64` are equivalent.

Headers:

Header	Description
Range	Download a specified byte range. Examples: `bytes=0-9` gets the first 10 bytes. `bytes=10-19` gets 10 bytes from the middle. `bytes=-10` gets the last 10 bytes. `bytes=9-` gets all bytes except the first 10. Only a single range is supported. The “If-Range” header is not supported. For more on the “Range” header, see https://developer.mozilla.org/en-US/docs/Web/HTTP/Range_requests

Header

Description

Range

Download a specified byte range. Examples:

bytes=0-9 gets the first 10 bytes.
bytes=10-19 gets 10 bytes from the middle.
bytes=-10 gets the last 10 bytes.
bytes=9- gets all bytes except the first 10.

Only a single range is supported. The “If-Range” header is not supported. For more on the “Range” header, see https://developer.mozilla.org/en-US/docs/Web/HTTP/Range_requests

Examples

A curl example of using the Range header to download the first 10 bytes of a file using its file id (database id):

export SERVER_URL=https://demo.dataverse.org
export FILE_ID=42
export RANGE=0-9

curl -H "Range:bytes=$RANGE" $SERVER_URL/api/access/datafile/$FILE_ID

The fully expanded example above (without environment variables) looks like this:

curl -H "Range:bytes=0-9" https://demo.dataverse.org/api/access/datafile/42

Multiple File (“bundle”) download

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

Alternate Form: POST to /api/access/datafiles with a fileIds input field containing the same comma separated list of file ids. This is most useful when your list of files surpasses the allowed URL length (varies but can be ~2000 characters).

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” above was in R);
Data (Variable) metadata record, in DDI XML;
File citation, in Endnote and RIS formats.

Parameters:

fileMetadataId

Value	Description
ID	Exports file with specific file metadata `ID`.

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 the verb above 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>

Parameters:

fileMetadataId

Value	Description
ID	Exports file with specific file metadata `ID`. For example for data file with id 6 and file metadata id 2: `curl 'http://localhost:8080/api/access/datafile/6/metadata/ddi?fileMetadataId=2'`

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 variables=123,127 in the example above.

Preprocessed Data

/api/access/datafile/$id?format=prep

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 earlier versions of Data Explorer, an external tool that integrates with a Dataverse installation (see External Tools). 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 verbs above 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’.

Allow Access Requests:

Allow or disallow users from requesting access to restricted files in a dataset where id is the database id of the dataset or pid is the persistent id (DOI or Handle) of the dataset to update.

A curl example using an id:

curl -H "X-Dataverse-key:$API_TOKEN" -X PUT -d true http://$SERVER/api/access/{id}/allowAccessRequest

A curl example using a pid:

curl -H "X-Dataverse-key:$API_TOKEN" -X PUT -d true http://$SERVER/api/access/:persistentId/allowAccessRequest?persistentId={pid}

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