Compatibility

nREPL officially targets LTS releases and the most recent rapid release version. More generally speaking - we aim to support all Java releases that are currently officially supported by Oracle.

This is currently Java 8, 11, 17, 21, and 22.

nREPL targets Clojure 1.7+. As Clojure doesn’t have the concept of supported releases we have to get a bit creative to determine the minimum version to target.

The minimum required Clojure version is currently derived using data from the State of Clojure survey. In general we consider a Clojure release eligible for dropping once its usage drops below 5%, but we’d not drop support for any release just for the sake of doing it. We’d do it only if this would lessen the maintenance burden or open up the possibility for big nREPL improvements.

Below you can find the official compatibility matrix for nREPL. For a very long time the project targeted JDK 5 and Clojure 1.2, but the requirements were bumped in nREPL 0.4.

In general, nREPL behavior does not depend on the versions of Java and Clojure. As of now, there is one exception to this rule, see JVMTI agent page.

It’s extremely unlikely that we’re going to break compatibility on the protocol level ever (with the rare cases of changing/removing things that existed, but we knew for a fact weren’t used). Most often backwards compatibility would be broken on the implementation level (usually it’s just removal of deprecated functionality).

That would always happen with plenty of lead time and would be annotated accordingly in the changelog.