Jolt nREPL for Kimi Code

A Kimi Code plugin that evaluates Clojure code in a persistent Jolt nREPL session. The plugin itself is written in Jolt and uses jolt-lang/nrepl for its direct bencode/TCP client.

Features

• Lazy connection from the project's .nrepl-port
• One cloned session with persistent vars, namespaces, and loaded dependencies
• Evaluation with values, stdout, stderr, namespace, and error status
• Project-contained load-file support
• Missing-delimiter repair with an explicit notice
• Timeouts, forced disconnect, and no automatic replay after transport failure
• Interrupt when the server advertises interrupt middleware
• A session-start skill with Jolt development and testing workflows

The plugin does not start or own your Jolt nREPL server. Start it in the project and leave it running:

jolt nrepl-server 0

Port 0 asks the OS for a free port and writes the selected port to .nrepl-port.

Requirements

• Jolt 0.8.13 or newer on PATH
• Kimi Code with plugin and MCP support
• Network access and Jolt's normal dependency tools for the first dependency resolution

From this directory, prefetch the pinned dependencies:

jolt -P

Install

Install the local directory using its absolute path:

/plugins install /Users/yogthos/src/jlt-commons/kimi-nrepl-plugin

Then run /reload or /new. Kimi runs the plugin from its managed copy, so reinstall after changing this source directory.

Tools

All eval/connect/load-file calls require the workspace's absolute cwd; the MCP process itself runs from the plugin directory.

Tool	Arguments	Purpose
nrepl_connect	cwd, optional host, port	Connect or switch projects; reads .nrepl-port when port is omitted
nrepl_eval	cwd, code, optional timeoutMs	Evaluate in the persistent session, connecting lazily if needed
nrepl_load_file	cwd, file, optional timeoutMs	Load a real file contained under the project root
nrepl_status	none	Show project, session, busy state, and interrupt capability
nrepl_interrupt	none	Request interruption of the active eval when supported
nrepl_disconnect	none	Close the session and socket; idempotent

timeoutMs defaults to 120000 and accepts 1–300000. On timeout, the client requests interrupt when available, waits up to one second for the final response, and closes its connection so late messages cannot contaminate another eval. Without confirmed interrupt, server-side termination is uncertain.

A second eval while one is active returns a busy error. Connect is also rejected while busy. Disconnect is the explicit escape hatch: it tears down the active request and never replays the form.

Optional interrupt middleware

Jolt's built-in handler supports clone, describe, eval, load-file, and close. Add the rich middleware to the project's deps.edn for interrupt and other standard operations:

{:deps {jolt-lang/nrepl {:git/url "https://github.com/jolt-lang/nrepl"
                         :git/tag "v0.4.0"
                         :git/sha "16558b920864e5302a5c1433a78f977bbb64a9d1"}}
 :nrepl/middleware [nrepl.middleware/default-middleware]}

Restart jolt nrepl-server after changing dependencies. Interrupt works at safe points in compute-bound code; it cannot preempt a foreign call until that call returns.

Development and verification

jolt -P
jolt -M:test

The suite covers delimiter repair, JSON-RPC/MCP handling, real base and rich nREPL servers, persistent eval, load-file, errors, Unicode, timeout, interrupt, disconnect, restart/no-replay behavior, and the actual MCP stdio process.

Troubleshooting

• No .nrepl-port: start jolt nrepl-server 0 in the intended project and wait for the file.
• Project mismatch: call nrepl_connect with the new absolute cwd; eval will not silently reuse another project's session.
• Interrupt unsupported: install nrepl.middleware/default-middleware and restart the server. A closed client socket alone does not prove the server-side form stopped.
• Dependency startup failure: run jolt -P in the plugin directory and inspect Jolt's normal dependency/network diagnostics.
• Source changes do not appear in Kimi: reinstall the plugin, then /reload or /new, because Kimi uses its managed copy.