@waddie/nautilos

An agent-facing nREPL tool. A small native daemon plus a thin CLI let an agent evaluate code in any nREPL server (Clojure, babashka, Janet, Steel, basilisp, ...) and keep accrued REPL state across calls.

Written in Janet for small, native binaries with no runtime requirement.

Install

npm install -g @waddie/nautilos

The binary for your OS/arch is selected via optional dependencies, so there are no install scripts. Prebuilt binaries cover darwin and linux on arm64 and x64; Linux builds are glibc-linked (not musl/Alpine).

Use

From a project directory that already runs an nREPL server:

nautilos eval '(def x 41)'     # auto-starts the daemon
nautilos eval '(+ x 1)'        # => value "42": state persisted across processes
nautilos describe
nautilos down

The port comes from a .nrepl-port file when present, or --port <n>. Every command prints one JSON object; read status for success or error.

nautilos mcp runs a JSON-RPC 2.0 stdio MCP server exposing the same operations as tools, for harnesses that register MCP servers.

See the project README for the full command and output reference, MCP registration, and agent-harness integration.

License

MIT. Copyright © 2026 Tom Waddington.