aowl-code — Nim/Nimony Claude Code plugin & MCP server

A Claude Code plugin that mediates agent access to the Nim and Nimony toolchains through structured tools, so an agent works from compact diagnostics, outlines, and targeted NIF slices instead of raw compiler output and multi-hundred-kilobyte S-expression artifacts.

Repo → github.com/aoughwl/aowl-code

The repo was renamed nim-code → aowl-code. The installed plugin's command namespace (/nim-code:*) and marketplace slug still read nim-code until the plugin manifest is republished.

The plugin supports both toolchains from one interface: the same commands and tools operate on Nim (nim, nimsuggest, nimble) and on Nimony (nimony, nimsem, hastur, and the nimcache/*.nif artifacts its pipeline emits). Toolchain selection is automatic and overridable.

• Why
• What's in it
• Install

---

Why

Both toolchains produce output that is costly to pass through an agent verbatim. The plugin targets six recurring sources of token waste:

Source	Cost	Mitigation
NIF artifacts in nimcache/	a single lowered .nif is 160 KB–700 KB of parenthesized S-expression	read only via nif_outline / nif_query / nif_diff / nif_render; direct reads intercepted by hooks
Noisy compiler output	nimony c / hastur interleave nifmake: / FAILURE: / niflink with real diagnostics	compile parses diagnostics; a PostToolUse hook strips noise
nimony c exits 0 on failure	the exit code is unreliable	failure determined by parsing for an Error: diagnostic, not exit status
Large NIF test diffs	hastur --overwrite diffs run to thousands of lines	nif_diff collapses unchanged regions to a structural diff
Symbol lookup across a large tree	grep is repetitive and unbounded	symbols (name) and defs_uses (position) return structured results in one call
Repeated context loss	the NIF tag vocabulary + Nim/Nimony distinction re-derived each session	shipped as on-demand skills; a project map lives in persistent memory

What's in it

• MCP tools — compile, build, outline, symbols, defs_uses, nif_outline / nif_query / nif_diff / nif_render, explain_failure, shrink, phase_report, api, and more.
• Terse / builder modes — compact file:line output; a build-and-report loop.
• Hooks — intercept raw NIF reads and strip build noise automatically.
• Skills & subagents — the NIF format, phase pipeline, and debug loops shipped as on-demand skills; specialized subagents (nif-inspector, nim-fixer).
• Optional LSP integration.

Install

Loaded from a plugin directory — nothing is published to a registry:

claude --plugin-dir /path/to/aowl-code

See the full reference for the complete MCP tool reference, configuration, hooks, and toolchain-detection details.