How to use OA Web service at ncbi.nlm.nih.gov/pmc/utils/oa/oa.fcgi?

PMC OA Web Service at ncbi.nlm.nih.gov/pmc/utils/oa/oa.fcgi allows you to discover downloadable resources from the PMC Open Access Subset. These articles are available for download from our FTP site in tgz (tar'd, gzipped) format, or, for those articles that have them, in PDF format as well.

Technical information PMC OA Web Service:

URL: https://www.ncbi.nlm.nih.gov/pmc/utils/oa/oa.fcgi?{parameters}

Supported parameters are:

• id={pmcid} - Specify a single research paper by the PMCID.
• from={time} - Specify the starting time of a research paper update window in YYYY-MM-DD HH:MM:SS format.
• until={time} - Specify the ending time of a research paper update window in YYYY-MM-DD HH:MM:SS format.
• format=pdf - Specify research papers that have PDF files.
• resumptionToken={token} - Specify research papers of the next page with the token given from the last call.

If the PMC OA Web Service is called without any parameters, it will return the server information:

fyicenter$ curl https://www.ncbi.nlm.nih.gov/pmc/utils/oa/oa.fcgi

<OA>
  <responseDate>2021-03-15 18:07:50</responseDate>
  <request>https://www.ncbi.nlm.nih.gov/pmc/utils/oa/oa.fcgi</request>
  <repositoryName>PubMed Central Open Access FTP Repository</repositoryName>
  <formats>
    <format>tgz</format>
    <format>pdf</format>
  </formats>
  <records>
    <count>3454737</count>
    <count format="tgz">3454736</count>
    <count format="pdf">816971</count>
    <latest>2021-03-15 13:16:22</latest>
  </records>
</OA>

If the id={pmcid} parameter is provided, it will return the research paper record of the given PMCID:

fyicenter$ curl https://www.ncbi.nlm.nih.gov/pmc/utils/oa/oa.fcgi?id=PMC5334499

<?xml version="1.0"?>
<OA>
  <responseDate>2022-10-13 23:00:36</responseDate>
  <request id="PMC5334499">https://www.ncbi.nlm.nih.gov/pmc/utils/oa/oa.fcgi?id=PMC5334499</request>
  <records returned-count="2" total-count="2">
    <record id="PMC5334499" citation="World J Radiol. 2017 Feb 28; 9(2):27-33" license="CC BY-NC" retracted="no">
      <link format="tgz" updated="2021-12-16 16:16:38" 
        href="/ftp://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_package/8e/71/PMC5334499.tar.gz"/>
      <link format="pdf" updated="2017-03-03 06:05:17" 
        href="/ftp://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/8e/71/WJR-9-27.PMC5334499.pdf"/>
    </record>
  </records>
</OA>

Then you can follow the links in the response to the package file or the PDF file of the research paper.

⇒ ftp.ncbi.nlm.nih.gov/pub/pmc - FTP Service

⇐ ncbi.nlm.nih.gov/pmc - Search PMC

⇑ PubMed Central (PMC) DOI Database

⇑⇑ DOI - Frequently Asked Questions