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At the HTTP level, Fedora 4 has two optional components, RSS feeds (pull) and Webhooks (push).
Webhooks
fcrepo-webhooks is an optional module. Webhooks allows you to register a callback url as a lightweight means of acting on repository events. The callback url will receive a POST request when an event is triggered with information about the event that triggered it.
fcrepo-irc provides a proof-of-concept application that uses Fedora's webhooks to post messages to an IRC channel when a repository event occurs.
fcrepo-kitchen-sink includes fcrepo-webhooks (along with all the other optional modules).
RSS
fcrepo-rss is an optional module that publishes a list of recent events.
fcrepo-kitchen-sink includes fcrepo-rss (along with all the other optional modules).
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