abcop MCP server

abcop

A must-have gate for AI-written code. Agents ship faster than humans can re-read; abcop keeps that code understandable by gating function and module ABC complexity so every unit fits a human head and an LLM context window. Diagnostics are also a hook for automated refactoring — extract a method, split a module — so CI rejects bad growth and points agents at concrete maintainability fixes.

One self-contained binary across Ruby, Rust, Python, Go, PHP, Java, C#, Dart, JavaScript, TypeScript, C, C++, Objective-C, Swift, Solidity, Zig and Haskell — no runtimes, no plugins, no per-language installs. Written in Rust for speed: one parse per file, one walk per metric, grammars compiled in; whole trees in milliseconds.

Install

brew install adrianov/abcop/abcop

cargo install abcop

macOS (.tar.gz from GitHub Releases; binary + man):

# Apple Silicon — use the *-x86_64-apple-darwin.tar.gz asset on Intel Macs
curl -LO https://github.com/adrianov/abcop/releases/download/v0.19.1/abcop-0.19.1-aarch64-apple-darwin.tar.gz
tar -xzf abcop-0.19.1-aarch64-apple-darwin.tar.gz
sudo cp abcop-0.19.1-aarch64-apple-darwin/abcop /usr/local/bin/
sudo mkdir -p /usr/local/share/man/man1
sudo cp abcop-0.19.1-aarch64-apple-darwin/abcop.1 /usr/local/share/man/man1/

Ubuntu / Debian (.deb from GitHub Releases; amd64, Ubuntu 22.04+ / Debian bookworm+):

# example for v0.19.1 — use the asset name from the release page
curl -LO https://github.com/adrianov/abcop/releases/download/v0.19.1/abcop_0.19.1-1_amd64.deb
sudo dpkg -i abcop_0.19.1-1_amd64.deb
man abcop

Example run

lib/sinatra/base.rb:1254:0: C: Metrics/AbcSize: Assignment Branch Condition size for `error_block!` is too high. [<7, 14, 9> 18.06/17]
src/main.rs: W: Metrics/ModuleAbcSize: Assignment Branch Condition size for module is too high. [<80, 200, 60> 228.04/120] -- extract a coherent subunit
132 files analysed in 0.09s, 7 abc offenses, 0 used-once offenses, 0 never-used warnings, 14 module-abc warnings

Why ABC, not line counts

Line counts lie. The ABC metric (Jerry Fitzpatrick, C++ Report, June 1997) counts what does work — assignments (A), branches (B), conditions (C) — as sqrt(A² + B² + C²). Fitzpatrick defined both method and module scope; abcop gates both:

A sparse wrapper and a dense god-object can share a line count; ABC separates them. Complexity is the gate — never a line budget. UsedOnce / NeverUsed are secondary.

Built for AI workflows

Shortened. The full README is on GitHub.