Does anyone know of a nexus plugin or APIs that allows the monitoring of mvn artifacts deployments to a nexus repo? my issue is that developers are uploading all kind of jar
As stated in the other answer there are a number of RSS feeds. In terms of who did what and tracking that even in the OSS version you can set up different users and roles. Just give each user their own username and password and only give deployment rights to the ones you trust to do the right thing..
There are several RSS feeds for broadcasting notifications of events within Nexus.
To monitor new deployments I'd suggest:
http://nexushost:8081/nexus/service/local/feeds/recentlyDeployedArtifacts
As for implementing deployment rules, your options are more limited. Nexus Professional has the ability to apply rules, however this only works as part of the build promotion functionality. Not sure how flexible this functionality is, and it's not part of the OSS edition.