CIDER is an Emacs minor-mode that extends the editor with interactive development capabilities for Clojure and ClojureScript. It complements clojure-mode and clojure-ts-mode by adding support for interacting with a running Clojure process, enabling compilation, code completion, debugging, definition and documentation lookup, and test execution directly from the editor.
The tool solves the problem of bridging the gap between source code editing and runtime interaction in Clojure development. Rather than switching between separate tools, CIDER integrates a live Clojure process into Emacs itself through an nREPL connection. Developers can evaluate code, inspect results, and debug without leaving their editor. The approach centers on cider-mode, a minor-mode that layers interactive programming features onto existing Clojure editing support.
CIDER suits developers who work in Emacs and want a tightly integrated Clojure development experience. It is particularly valuable for those practicing interactive programming workflows where rapid feedback from a running process accelerates development. The tool is designed for projects using standard Clojure build tools like Leiningen or tools.deps, which it can automatically detect and launch. Adoption requires Emacs and basic familiarity with its package management system, as CIDER installs through the standard package.el mechanism available on major package repositories.
The project maintains active continuous integration across multiple test workflows including integration tests and spell-checking. Development activity is sustained through ongoing maintenance and feature work, with the tool receiving regular updates to support evolving Clojure tooling and Emacs versions. The project operates an open community presence through Discord and Slack channels, indicating active engagement with users and contributors.
