BioStudies

EMBL-EBI archive for the data outputs of a life-science study: files hosted here, plus links out to ArrayExpress, BioImages, ENA, and other archives. Use it when the user wants the dataset behind a paper, a BioStudies accession (S-BSST…, S-EPMC…, S-CMO…, E-MTAB…), or "supplementary data at EBI." It is not a paper index.

Find the paper in PubMed / Europe PMC, then come here with an accession or a keyword that appears in the study record.

All figures below verified 2026-09-10.

Base URL

https://www.ebi.ac.uk/biostudies/api/v1

Authentication

None.

Rate Limits

No published per-second cap. Serialize. EBI asks for reasonable use.

Key Endpoints

1. Search studies

GET /search?query={text}&page={n}&pageSize={n}

GET /search?query=organoid&pageSize=2

Verified: HTTP 200 with

A hit has accession, type (study), title, author, files (count), release_date, isPublic, content (a flattened text blob). author may be an empty string.

totalHits moved by hundreds between two calls a few seconds apart, and isTotalHitsExact stayed false. Report "about N studies" and the page you fetched. Do not claim a complete walk against that number.

Page 2 (page=2&pageSize=2) returned different accessions and still nextCursor: null. Keep incrementing page until hits is empty.

2. One study

GET /studies/{accession}

GET /studies/S-CMO2844

Verified: HTTP 200. The body is not the search-hit shape:

{
  "accno": "S-CMO2844",
  "type": "submission",
  "attributes": [{"name": "Title", …}, {"name": "ReleaseDate", …}],
  "section": { "type": "Study", "accno": "s1", "attributes": […], "subsections": […] }
}

Title lives in attributes (name Title), not title. Files and links are nested under section.subsections. Walk that tree; do not expect files: [ …urls ] at the top level.

A 404 means no such public accession.

Typical Workflow

1. Search with a paper title, accession, or biological keyword.
2. Take accession from hits[].
3. GET /studies/{accession} for the submission tree and file list.
4. Cite the accession and the BioStudies URL (https://www.ebi.ac.uk/biostudies/studies/{accession}).
5. If they wanted the paper, go back to PubMed / Europe PMC with the title or a DOI found in the study attributes.

Failure Modes