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.
git clone --depth 1 https://github.com/damien-schneider/agent-skills-libraryWrote 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.
[](https://agentmods.dev/rules/damien-schneider/agent-skills-library/ultracite)<a href="https://agentmods.dev/rules/damien-schneider/agent-skills-library/ultracite"><img src="https://agentmods.dev/badge/rules/damien-schneider/agent-skills-library/ultracite/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.
<a href="https://agentmods.dev/rules/damien-schneider/agent-skills-library/ultracite"><img src="https://agentmods.dev/badge/rules/damien-schneider/agent-skills-library/ultracite.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.01084 | $0.01084 |
| Opus 5 | $0.00542 | $0.00542 |
| Sonnet 5 | $0.00217 | $0.00217 |
| Haiku 4.5 | $0.00108 | $0.00108 |
Grade A, and why
ultracite 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 10d 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.
How it starts
The opening of the file, as written. The whole thing — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Ultracite Code Standards
This project uses Ultracite, a zero-config preset that enforces strict code quality standards through automated formatting and linting.
Quick Reference
- Format code:
bun x ultracite fix - Check for issues:
bun x ultracite check - Diagnose setup:
bun x ultracite doctor
Biome (the underlying engine) provides robust linting and formatting. Most issues are automatically fixable.
Core Principles
Write code that is accessible, performant, type-safe, and maintainable. Focus on clarity and explicit intent over brevity.
Type Safety & Explicitness
- Use explicit types for function parameters and return values when they enhance clarity
- Prefer
unknownoveranywhen the type is genuinely unknown - Use const assertions (
as const) for immutable values and literal types - Leverage TypeScript's type narrowing instead of type assertions
- Use meaningful variable names instead of magic numbers - extract constants with descriptive names
Modern JavaScript/TypeScript
- Use arrow functions for callbacks and short functions
- Prefer
for...ofloops over.forEach()and indexedforloops - Use optional chaining (
?.) and nullish coalescing (??) for safer property access - Prefer template literals over string concatenation
- Use destructuring for object and array assignments
- Use
constby default,letonly when reassignment is needed, nevervar
Async & Promises
- Always
awaitpromises in async functions - don't forget to use the return value - Use
async/awaitsyntax instead of promise chains for better readability - Handle errors appropriately in async code with try-catch blocks
- Don't use async functions as Promise executors
React & JSX
- Use function components over class components
- Call hooks at the top level only, never conditionally
- Specify all dependencies in hook dependency arrays correctly
- Use the
keyprop for elements in iterables (prefer unique IDs over array indices) - Nest children between opening and closing tags instead of passing as props
- Don't define components inside other components
- Use semantic HTML and ARIA attributes for accessibility:
- Provide meaningful alt text for images
- Use proper heading hierarchy
- Add labels for form inputs
- Include keyboard event handlers alongside mouse events
- Use semantic elements (
<button>,<nav>, etc.) instead of divs with roles
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.
- 10d ago First seen · 124 lines · 1,084 tokens per session scan A e14e13147efb
ultracite is a cursor rule published in the GitHub repository damien-schneider/agent-skills-library (7 stars, last pushed 16d ago), licensed MIT. It adds 1,084 tokens to every session, about $0.0054 per session on Opus 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 2026-08-31.
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