006-utils

Guidelines for writing reusable helper functions for Koota, Three.js, and game-world calculations. Three.js is a JavaScript library for displaying and manipulating 3D graphics in the browser.

In plain words
What is it for?
Use them for reading entity data, reusing 3D math objects, managing arrays or buffers, clamping values, and building spatial partitioning for large worlds. Spatial partitioning groups objects so nearby-object searches do less work.
Why use it?
They help avoid repeated calculations, unnecessary object creation, missing-data errors, and unhandled edge cases. This can make frequently used game code easier to maintain and run efficiently.

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/instructa/viber3d/006-utils
Clone the repo
git clone --depth 1 https://github.com/instructa/viber3d

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 186 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 $0.00186
Opus 5 $0.00000 $0.00093
Sonnet 5 $0.00000 $0.00037
Haiku 4.5 $0.00000 $0.00019

Measured yesterday against content hash 20c921af70ca, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

006-utils 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.

templates/starter-next/.cursor/rules/006-utils.mdc · 31 lines

What it actually says

Koota Integration

  • Access entity traits with entity.get(Trait).
  • Handle missing traits gracefully, using null checks when necessary.

Three.js Usage

  • Reuse math objects like Vector3 to reduce garbage collection.
  • Leverage built-in Three.js methods for transformations instead of reinventing them.

Performance

  • Reuse arrays or buffers for spatial and geometry operations.
  • Implement spatial partitioning (quadtrees, hash grids) for large worlds.
  • Provide reset methods to avoid creating new data structures every frame.

Math Utilities

  • Consolidate common math operations in concise functions.
  • Ensure edge cases are handled (e.g. clamping, bounding conditions).

Documentation

  • Add clear comments and note any adapted third-party code.
  • Highlight performance considerations for complex or frequently used utilities.
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 · 31 lines · 0 tokens per session scan A 20c921af70ca

Subscribe to this mod's changes

006-utils is a cursor rule published in the GitHub repository instructa/viber3d (623 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 186 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 2026-08-30.