cube-engine

Guidance for the Rust code that represents a Rubik’s Cube, applies moves, reads cube notation, creates scrambles, and checks whether a cube state is valid. Rust is the programming language used for this engine.

In plain words
What is it for?
Use it when changing cube state, move behavior, notation parsing, scramble generation, or cube validation.
Why use it?
It protects the basic cube rules that solving algorithms and other parts of the application depend on.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/williamisnotdefined/rubiks-cube-solver/cube-engine
Clone the repo
git clone --depth 1 https://github.com/williamisnotdefined/rubiks-cube-solver

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 2,936 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.02936
Opus 5 $0.00000 $0.01468
Sonnet 5 $0.00000 $0.00587
Haiku 4.5 $0.00000 $0.00294

Measured yesterday against content hash 8639dd825816, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cube-engine scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/cube-engine.mdc · 275 lines

How it starts

The opening of the file, as written. The whole thing — 275 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Generated from ai/registry.json. Do not edit manually.

Canonical skill: ../../ai/skills/cube-engine.md.

Referenced context:

  • ../../ai/rules/cube-engine-rules.md
  • ../../ai/rules/testing-rules.md
  • ../../ai/architecture/project-architecture.md
  • ../../ai/architecture/cube-engine.md
  • ../../ai/glossary/cube-terms.md

This file is compiled from canonical AI knowledge files. Edit canonical files under ai, then run npm run ai:sync.

Compiled AI Skill: cube-engine

Canonical Skill: ai/skills/cube-engine.md

Cube Engine

Use this skill when adding or changing the Rust cube representation, moves, notation, scrambles, or cube validation.

Goal

Build the pure Rust engine first, using cubie representation and deterministic behavior that later search algorithms can trust.

Read First

  • ai/rules/cube-engine-rules.md
  • ai/rules/testing-rules.md
  • ai/architecture/project-architecture.md
  • ai/architecture/cube-engine.md
  • ai/glossary/cube-terms.md

Workflow

  • Keep work inside crates/cube-engine unless a current boundary requires otherwise.
  • Start with cubie state invariants before adding higher-level algorithms.
  • Keep notation parsing and state mutation separate.
  • Add tests for solved state, move/inverse behavior, and invalid notation as behavior appears.
  • Fail explicitly for bootstrap placeholders rather than silently producing incorrect cube states.

Expected Output

  • Primary state remains corner/edge permutation and orientation.
  • Move behavior is reversible and tested when implemented.
  • No JavaScript visualization dependency enters the Rust engine.

Verification

  • Run cargo test -p cube-engine when Rust is installed.
  • If Rust is unavailable, state the environment blocker clearly.

Referenced Context

Reference: ai/rules/cube-engine-rules.md

Cube Engine Rules

Rules for the Rust cube engine.

Always

  • Use cubie representation as the primary state model: corner permutation, corner orientation, edge permutation, and edge orientation.
  • Keep move application pure and deterministic.
  • Make every implemented move reversible and test the inverse path.
  • Validate state invariants before solver algorithms depend on them.
  • Keep notation parsing separate from state mutation.
  • Keep serialization explicit and stable once external consumers exist.
  • When adding puzzles beyond 3x3, keep each puzzle's state representation, move model, notation parser, validator, and solver strategy puzzle-specific.

Read the full file on GitHub · 275 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 275 lines · 0 tokens per session scan A 8639dd825816

Subscribe to this mod's changes

cube-engine is a cursor rule published in the GitHub repository williamisnotdefined/rubiks-cube-solver (4 stars, last pushed 8d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 2,936 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.