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/virastack/aiWrote 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/virastack/ai/react-best-practices)<a href="https://agentmods.dev/rules/virastack/ai/react-best-practices"><img src="https://agentmods.dev/badge/rules/virastack/ai/react-best-practices/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/virastack/ai/react-best-practices"><img src="https://agentmods.dev/badge/rules/virastack/ai/react-best-practices.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 | $0.00000 | $0.00345 |
| Opus 5.5 | $0.00000 | $0.00138 |
| Sonnet 5.5 | $0.00000 | $0.00069 |
| Haiku 4.5 | $0.00000 | $0.00034 |
Grade A, and why
react-best-practices 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 1mo 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- react-best-practices — 100% identical, 7 lines differ
What it actually says
React Best Practices
Constraints
- SRP: Keep components small (max 200 lines).
- Composition: Use
childrenorslotsinstead of prop drilling. - Naming: Use
PascalCasefor components,useCamelCasefor hooks. - Hooks: Move business logic to custom hooks.
- State: Lift state to the nearest common ancestor.
- Updates: Use
setState(prev => ...)for state updates. - Effects: Use
useEffectas a last resort. Prefer event handlers oruseMemo. - Keys: Use stable IDs for lists (index is forbidden).
Bans
- Prop drilling (>2 levels).
- Class components.
- Incomplete dependency arrays.
- Syncing props to state (use Derived state).
- Heavy computations during render.
- Data fetching inside components (violation of API rules).
Correct Implementation
Incorrect Implementation
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.
- 1mo ago First seen · 49 lines · 0 tokens per session scan A dddece490867
react-best-practices is a cursor rule published in the GitHub repository virastack/ai (23 stars, last pushed 2mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 345 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.
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