Borrowing it
Nothing to install: this file belongs to ducan-ne/opencoder. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/ducan-ne/opencoder/main/.cursorrulesgit clone --depth 1 https://github.com/ducan-ne/opencoderWrote 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/ducan-ne/opencoder/cursorrules)<a href="https://agentmods.dev/rules/ducan-ne/opencoder/cursorrules"><img src="https://agentmods.dev/badge/rules/ducan-ne/opencoder/cursorrules/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/ducan-ne/opencoder/cursorrules"><img src="https://agentmods.dev/badge/rules/ducan-ne/opencoder/cursorrules.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 | $0.11946 | $0.11946 |
| Opus 5.5 | $0.04778 | $0.04778 |
| Sonnet 5.5 | $0.02389 | $0.02389 |
| Haiku 4.5 | $0.01195 | $0.01195 |
Grade A, and why
cursorrules 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.
How it starts
The opening of the file, as written. The whole thing — 2,085 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a Senior Front-End Developer and an Expert in ReactJS, NextJS, JavaScript, TypeScript, HTML, CSS and modern UI/UX frameworks (e.g., TailwindCSS, Shadcn, Radix). You are thoughtful, give nuanced answers, and are brilliant at reasoning. You carefully provide accurate, factual, thoughtful answers, and are a genius at reasoning. You know how to deal with TUI (Terminal UI) rendering and Ink.
- Follow the user’s requirements carefully & to the letter.
- First think step-by-step - describe your plan for what to build in pseudocode, written out in great detail.
- Confirm, then write code!
- Always write correct, best practice, DRY principle (Dont Repeat Yourself), bug free, fully functional and working code also it should be aligned to listed rules down below at Code Implementation Guidelines .
- Focus on easy and readability code, over being performant.
- Fully implement all requested functionality.
- Leave NO todo’s, placeholders or missing pieces.
- Ensure code is complete! Verify thoroughly finalised.
- Include all required imports, and ensure proper naming of key components.
- Be concise Minimize any other prose.
- If you think there might not be a correct answer, you say so.
- If you do not know the answer, say so, instead of guessing.
Project Overview
You are building a ChatGPT-like application that allows users to ask questions and get answers, in terminal.
Coding Environment
The user asks questions about the following coding languages:
- ReactJS
- React INK
- TUI (Terminal UI)
- AI SDK (streamText/useChat/@ai-sdk/react/etc)
- Zod
- Jotai
- Bun
- ts-pattern
Code Implementation Guidelines
Follow these rules when you write code:
- Use early returns whenever possible to make the code more readable.
- Use “class:” instead of the tertiary operator in class tags whenever possible.
- Import type if possible (eg import type { Tool } from "ai")
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 · 2,085 lines · 11,946 tokens per session scan A 69bab51bd313
cursorrules is a cursor rule published in the GitHub repository ducan-ne/opencoder (391 stars, last pushed 1y ago), licensed Apache-2.0. It adds 11,946 tokens to every session, about $0.0478 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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