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/PaulJPhilp/EffectPatternsWrote 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/pauljphilp/effectpatterns/hello-world-your-first-effect)<a href="https://agentmods.dev/rules/pauljphilp/effectpatterns/hello-world-your-first-effect"><img src="https://agentmods.dev/badge/rules/pauljphilp/effectpatterns/hello-world-your-first-effect/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/pauljphilp/effectpatterns/hello-world-your-first-effect"><img src="https://agentmods.dev/badge/rules/pauljphilp/effectpatterns/hello-world-your-first-effect.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 | $0.00160 | $0.00160 |
| Opus 5.5 | $0.00064 | $0.00064 |
| Sonnet 5.5 | $0.00032 | $0.00032 |
| Haiku 4.5 | $0.00016 | $0.00016 |
Grade A, and why
hello-world-your-first-effect 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.
What it actually says
description: Create your first Effect program with Effect.succeed. globs: "**/*.ts" alwaysApply: true
Hello World: Your First Effect
Rule: Create your first Effect program with Effect.succeed.
Example
import { Effect } from "effect";
// Step 1: Create an Effect that succeeds with a value
const helloWorld = Effect.succeed("Hello, Effect!");
// Step 2: Run the Effect and get the result
const result = Effect.runSync(helloWorld);
console.log(result); // "Hello, Effect!"
Explanation:
Every journey starts with "Hello World". In Effect, you create computations
by describing what you want to happen, then you run them. This separation is
what makes Effect powerful.
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 · 25 lines · 160 tokens per session scan A c232531174f0
hello-world-your-first-effect is a cursor rule published in the GitHub repository PaulJPhilp/EffectPatterns (807 stars, last pushed 4mo ago), licensed MIT. It adds 160 tokens to every session, about $0.0006 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 2026-09-03.
Other cursor rules, from other repositories
naming-cheatsheet
Naming things is hard. This cheatsheet makes it easier. The codebase is primarily Python, so all examples use Python / PEP 8 conventions unless noted otherwise.
typescript-exhaustive-switch
Use exhaustive switch handling for TypeScript unions and enums.
tutor-behaviour
TypeScript learning tutor rules for this repository. Always apply.
typescript-code-generation-rules
Rules for generating TypeScript code in Next.js 14 components, including component definition syntax, props definitions, and named/default exports.
react-and-typescript-general-rules
General rules for React and TypeScript projects, focusing on code clarity and best practices.
typescript-coding-style
Enforces code style and best practices for TypeScript files.