COAR — Confederation of Open Access Repositories
Overview
COAR is an international not-for-profit association of repository initiatives, founded in October 2009 and representing over 140 member institutions from libraries, universities, research organisations, and funders across six continents. Its mission is to advance open access repositories as distributed, interoperable infrastructure for scholarly communication — positioning repositories not merely as storage but as active, machine-actionable nodes in a global scholarly network. COAR works closely with OpenAIRE, EOSC, and RDA, and advocates for repositories as the technical backbone of open science mandates including cOAlition S.
Next Generation Repositories and COAR Notify
COAR’s most significant technical contribution is the Next Generation Repositories initiative (report published 2017), which identified 19 technologies and protocols repositories should adopt to support machine access and interoperability. The recommended stack includes Signposting (typed links enabling machines to navigate from a landing page to content, metadata, and identifiers), ResourceSync (content synchronisation between repositories), and Linked Data Notifications. Building on this, COAR Notify (launched 2021) is a protocol for linking research outputs in repositories with external services such as overlay journals and open peer review platforms. It is based on two W3C standards: Linked Data Notifications and Activity Streams 2.0, and enables decentralised, message-based communication between repositories and publishing services without routing through centralised silos.
COAR Vocabularies
COAR maintains controlled vocabularies for resource types (article, dataset, software, preprint, and others) and access rights used in repository metadata, enabling consistent description across repository systems and aggregators. These vocabularies are referenced in the W3C DCAT specification and used by OpenAIRE and EOSC aggregation pipelines.
Connections
- relatedTo: OpenAIRE, EOSC, RDA
- relatedTo: cOAlition S
- relatedTo: FAIR Principles
Resources
- https://coar-repositories.org
- https://coar-repositories.org/what-we-do/next-generation-repositories/ (NGR initiative)
- https://coar-notify.net (COAR Notify protocol)
- https://ngr.coar-repositories.org (NGR technologies reference)
- https://vocabularies.coar-repositories.org (COAR Vocabularies)