comet: Instructions file for Codex

AGENTS.md

comet AGENTS.md is an instructions file for Codex, OpenCode from MetroStar/comet. It costs 397 tokens per session, scanned A, original, Apache-2.0.

Repository instructions for Comet, a React and TypeScript component library based on the U.S. Web Design System.

In plain words
What is it for?
Use them when adding or changing components, stories, tests, exports, or documentation in the library.
Why use it?
They define the project's required structure, naming, styling, testing, and component conventions.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

This is MetroStar/comet's own configuration. It tells Codex and OpenCode how to work on comet itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything comet configures →

Reuse

Borrowing it

Nothing to install: this file belongs to MetroStar/comet. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/MetroStar/comet/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/MetroStar/comet

Made for: Codex, OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for comet AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/metrostar/comet/agents-md/github.svg)](https://agentmods.dev/instructions/metrostar/comet/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/metrostar/comet/agents-md"><img src="https://agentmods.dev/badge/instructions/metrostar/comet/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for comet AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/metrostar/comet/agents-md"><img src="https://agentmods.dev/badge/instructions/metrostar/comet/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 397 This file is loaded in full into every session.
When invoked 397 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00397 $0.00397
Opus 5.5 $0.00159 $0.00159
Sonnet 5.5 $0.00079 $0.00079
Haiku 4.5 $0.00040 $0.00040

Measured 2mo ago against content hash 66a59c762b79, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

comet AGENTS.md 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 2mo ago.

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.

AGENTS.md · 51 lines

What it actually says

Comet

This project is a React with TypeScript Component Library based on USWDS. It is designed to provide a set of modular tools to accelerate developer productivity and simplify the use of Design Systems, particularly USWDS.

Project Structure

This project is built with the following tools and libraries:

  • React with TypeScript
  • Vite for managing React Development and Bundling
  • Vitest for unit testing, do not use Jest
  • USWDS for the primary Component Library
  • Storybook code examples and documentation

Development Guidelines

  • Use TypeScript for type safety.
  • All components should include an id prop.
  • Use arrow functions for components and hooks.
  • Use functional components instead of class components.
  • Components should return React.ReactElement.
  • Use default exports for components.
  • Use PascalCase for component names.
  • Use kebab-case for file names and directories.
  • New components should be added to their own directory and should include at least: component, stories, test, figma file, and index.
  • New components should be exported from an index.ts file in their directory.
  • New components should be exported from the main index.ts file in the package.
  • New components should include jsdoc comments.

Styling Guidelines

  • Use CSS for styling.
  • Component level styling should be in a .css file with the same name as the component.

Unit Testing

  • Use Vitest for unit testing, never use Jest.
  • Use React Testing Library for testing React components.
  • Use 'test' instead of 'it' for test names.

Code Quality

  • Use ESLint for code analysis.
  • Use Prettier for code formatting.

Accessibility

  • Ensure HTML is WCAG 2.1 AA and Section 508 compliant.
  • Ensure HTML meets accessibility best practices for screen readers, keyboard navigation, and color contrast.
  • Use semantic HTML and ARIA roles appropriately.
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. 2mo ago First seen · 51 lines · 397 tokens per session scan A 66a59c762b79

Subscribe to this mod's changes

comet AGENTS.md is an instructions file published in the GitHub repository MetroStar/comet (29 stars, last pushed 8d ago), licensed Apache-2.0. It adds 397 tokens to every session, about $0.0016 per session on Opus 5.5. 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.

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