It's not so easy, because many automation flows download slave.jar, windows-slave.exe and other such files from Jenkins. We can only add new endpoints and fix UIs, but the previous entries must be retained

Is eternal backward compatibility a core requirement? Can we create a plan for phasing these out? Provide both for some time period and then remove the old.

File names in particular heavily influence the terms people use when talking about the product and features. Keeping "slave" in the file names essentially defeats any effort to remove the term "slave" from association with our product. As part of this transition, we're seeing people add the term "agent" but not remove the term "slave" from descriptions. "I'm have a problem with my jenkins slave agent." To get people to drop "slave", I think we need to not show them "slave-blah" every time they start an agent.

> Can we create a plan for phasing these out? Provide both for some time period and then remove the old.

We cannot, because there is no API deprecation policy/engine.
As a remoting maintainer, I'm strongly -1 on removing original links within any visible timeframe. Too much fixing efforts and regressions due to just a renaming

The originally agreement was that the term slave would be removed from the UI, but left in the APIs to avoid breaking compatibility both for plugins and customer tools/scripts.   The problem is that line of where the UI stops and the API begins is a somewhat fluid when your users are engineers.

I understand that filenames and urls are effectively part of the API and so changing them is problematic and could be considered out of scope.   But filenames and urls are also part of the end-user experience (the UI) for every Jenkins user. And the files and urls related to adding an agent are some of the first and most commonly used.

Surely we can do a hard redirect when someone is asking for /slave.jar?

see https://github.com/jenkinsci/jenkins/pull/3004 as a minimal backward compatible fix. slave.jar still supported to ensure no regression, but document use of agent.jar

ndeloof Thanks!

Code changed in jenkins
User: Oleg Nenashev
Path:
core/src/main/java/hudson/FilePath.java
core/src/main/java/hudson/Launcher.java
core/src/main/java/hudson/model/Slave.java
core/src/main/java/hudson/slaves/Channels.java
core/src/main/java/hudson/slaves/CommandLauncher.java
core/src/main/java/hudson/slaves/SlaveComputer.java
core/src/main/resources/hudson/slaves/CommandLauncher/help-command.html
core/src/main/resources/hudson/slaves/CommandLauncher/help-command_bg.html
core/src/main/resources/hudson/slaves/CommandLauncher/help-command_fr.html
core/src/main/resources/hudson/slaves/CommandLauncher/help-command_ja.html
core/src/main/resources/hudson/slaves/CommandLauncher/help-command_ru.html
core/src/main/resources/hudson/slaves/JNLPLauncher/main.jelly
core/src/main/resources/windows-service/jenkins-slave.xml
test/src/test/java/hudson/model/Slave2Test.java
test/src/test/resources/hudson/model/update-center.json
http://jenkins-ci.org/commit/jenkins/0a2d6ca2bad601c2ad80502e0f4de861e93c6f2c
Log:
Merge pull request #3004 from ndeloof/agent

JENKINS-35451 - prefer ‘agent.jar’ over ‘slave.jar’

Compare: https://github.com/jenkinsci/jenkins/compare/7f093d3dd786...0a2d6ca2bad6

Fixed in 2.77.

Someone reported this issue as a problem on the changelog. Please indicate in a comment what the encountered problem is, nor file a separate issue for that, and link it here and/or from the changelog. Thanks!