Direct comparison
Coar Notify Vs Oai Pmh: Key Differences & Comparison | CASRAI
COAR Notify is a push-based, event-driven protocol for linking repository resources with services; OAI-PMH is a pull-based protocol for harvesting repository metadata. They serve different jobs.
Side-by-side comparison
| Dimension | COAR Notify | OAI-PMH |
|---|---|---|
| Purpose | Link repository resources with external services | Harvest repository metadata into a central index |
| Mechanism | Push-based, event-driven notifications | Pull-based, periodic metadata harvesting |
| Direction | Systems notify each other as events occur | A harvester requests records from a repository |
| Technology | Linked Data Notifications and Activity Streams 2.0 | HTTP verbs and Dublin Core metadata |
| What moves | Structured notifications about resources | Metadata records describing resources |
| Use case | Connect preprints to reviews, endorsements, overlays | Build aggregators and discovery services |
| Architecture | Distributed and decentralised | Centralising — feeds a central catalogue |
| Age / maturity | Newer; adoption growing | Long-established and widely deployed |
| Complementarity | Connects systems around resources | Aggregates metadata for discovery |
Common questions
FAQ
Does COAR Notify replace OAI-PMH?+
No — they solve different problems. OAI-PMH harvests metadata into central indexes for discovery, while COAR Notify exchanges event notifications between systems to link resources with services such as peer review. Many repositories can use both.
What does push-based versus pull-based mean here?+
OAI-PMH is pull-based: a harvester periodically asks a repository for its records. COAR Notify is push-based and event-driven: when something happens — say a review is created — a service sends a notification to the relevant repository, rather than waiting to be polled.
Why introduce a notification protocol at all?+
Harvesting is good for building catalogues but does not connect a resource to value-adding services in real time or in a distributed way. COAR Notify lets independent repositories and services link content, reviews, and endorsements without funnelling everything through one central platform.
Going deeper
