OAI-PMH stands for Open Archives Initiative – Protocol for Metadata Harvesting. It's a low-barrier mechanism for repositories and services to share metadata records. The protocol works across HTTP, with requests being made by URLs. Parameters and their values are case sensitive, and should be encoded in the 'query' portion of the URL (i.e. towards the end, after a question mark ? but before a hash #). Responses are returned as XML.
OAI-PMH provides six operations, or verbs in OAI parlance:
You can get output from the Hub using the OAI-PMH "harvesting" protocol
The endpoint of the primary OAI-PMH server is
The data is available in two formats, each identified in the protocol by a metadataPrefix
EAD XML - the full record used by the Hub
Our OAI-PMH server provides sets, so that harvesters can use the protocol to access only the subset of data we hold for a specific institution.