browser-api-usage-rules

Coding rules for Chrome extension code written in JavaScript or TypeScript. They cover common browser APIs, error handling, and scheduled tasks.

In plain words
What is it for?
Use them when working with Chrome tabs, saved extension data, background runtime functions, or scheduled jobs.
Why use it?
They help avoid unreliable API calls and inefficient timer-based scheduling. They also keep browser extension code more consistent.

Cursor rule

Install

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.

agentmods
npx agentmods add rules/toptalentcoder/cursor-awesomerules/browser-api-usage-rules
Clone the repo
git clone --depth 1 https://github.com/toptalentcoder/Cursor-AwesomeRules
Per session 72 This file is loaded in full into every session.
When invoked 72 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod 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 $0.00072 $0.00072
Opus 5 $0.00036 $0.00036
Sonnet 5 $0.00014 $0.00014
Haiku 4.5 $0.00007 $0.00007

Measured 2d ago against content hash 6644fdc50335, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

browser-api-usage-rules 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 2d 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.

Origin

This is a copy

100% identical to browser-api-usage-rules — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

rules/chrome-extension-dev-js-typescript-cursorrules-pro/browser-api-usage-rules.mdc · 7 lines

What it actually says


description: Rules for effectively utilizing Chrome's browser APIs, including error handling and scheduling tasks. globs: **/*.{js,ts}

  • Utilize chrome.* APIs effectively (e.g., chrome.tabs, chrome.storage, chrome.runtime)
  • Implement proper error handling for all API calls
  • Use chrome.alarms for scheduling tasks instead of setInterval
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. 2d ago First seen · 7 lines · 72 tokens per session scan A 6644fdc50335

Subscribe to this mod's changes

browser-api-usage-rules is a cursor rule published in the GitHub repository toptalentcoder/Cursor-AwesomeRules (6 stars, last pushed 1y ago), licensed CC0-1.0. It adds 72 tokens to every session, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to browser-api-usage-rules, differing in 0 lines, and is treated as a copy.