Our REST API makes all of the metadata we hold publicly available. It receives the majority of our API traffic, with around 1 billion hits per month. It’s one of the key ways that we fulfil our mission to make research objects easy to find, cite, link, assess, and reuse. From 1 December 2025, we will be revising the rate limits for the public and polite pools of the REST API to ensure that we can maintain a stable and reliable system, and that metadata is freely available to everyone.
Noyam Journals, based in Accra, Ghana, was recently recognised for the completeness of its metadata through the Crossref Metadata Award, part of our 25th anniversary celebrations. Noyam was one of six publishers worldwide to receive the award and stood out as a leader among members of our Global Equitable Membership (GEM) Program.
Wednesday 22nd October 2025—Crossref, the open scholarly infrastructure nonprofit, today releases an enhanced dashboard showing metadata coverage and individual organisations’ contributions to documenting the process and outputs of scientific research in the open. The tool helps research-performing, funding, and publishing organisations identify gaps in open research information, and provides supporting evidence for movements like the Barcelona Declaration for Open Research Information, which encourages more substantial commitment to stewarding and enriching the scholarly record through open metadata.
Welcome back to our series of case studies of research funders using the Grant Linking System. In this interview, I talk with Cátia Laranjeira, PTCRIS Program Manager at FCCN|FCT, Portugal’s main public funding agency, about the agency’s approach to metadata, persistent identifiers, Open Science and Open Infrastructure.
With a holistic approach to the management, production and access to information on science, FCCN|FCT’s decision to implement the Grant Linking System within their processes was not simply a technical upgrade, but a coordinated effort to continue building a strong culture of openness. With the mantra “register once, reuse always”, FCCN|FCT efforts to embrace open funding metadata was only logical.
Registering your DOI records using the OJS platform
In order to register DOI records with Crossref, you need to set up your OJS (Open Journal Systems) platform to create DOIs on your Crossref DOI prefix, and also set up your OJS platform to send your records to Crossref. You do this in a different way depending on whether you are using OJS 3.4 or OJS 3.3:
You can download the newest versions of OJS in the Public Knowledge Project’s (PKP) documentation.
Additional OJS plugins for Crossref
There are also other important plugins that can be enabled in OJS to enrich your metadata records:
Funding Metadata plugin - as of OJS 3.1.2, it is possible to enable a funder registry plugin for submitting funding information to Crossref. The plugin will use the Open Funder Registry to check against existing funding agencies. The plugin will include funding information in your Crossref DOI deposits.
Similarity Check plugin - if you are using OJS 3.1.2 or above, you are able to use the Similarity Check plugin. This will enable you to automatically send manuscripts to your iThenticate account to check their similarity to already published content. You will need to be subscribed to Crossref’s Similarity Check service for this to work.
ROR plugin - the ROR Plugin for OJS enables authors to add the ROR ID for the organization they are affiliated with.
Getting help with OJS plugins
The team at Crossref didn’t create these plugins - they were either created by the team at PKP, or by third-party developers. Because of this, we aren’t able to give in-depth help or troubleshooting on problems with these plugins.
