01-diagnose-before-fixing

01-diagnose-before-fixing is a cursor rule for Cursor from reillyjodonnell/react-debugger. It costs 140 tokens per session, scanned A, original, MIT.

A rule requiring developers to investigate React bugs with debugging tools before editing or proposing code changes.

In plain words
What is it for?
Use it when diagnosing React problems, where React is a JavaScript library for building user interfaces.
Why use it?
It prevents guesses by requiring evidence about the component's updates, properties, or internal state first.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit Use it when diagnosing React problems, where React is a JavaScript library for building user interfaces.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/reillyjodonnell/react-debugger/01-diagnose-before-fixing
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.

Clone the repo
git clone --depth 1 https://github.com/reillyjodonnell/react-debugger

Made for: Cursor.

Wrote 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.

agentmods badge for 01-diagnose-before-fixing

README.md
[![agentmods](https://agentmods.dev/badge/rules/reillyjodonnell/react-debugger/01-diagnose-before-fixing/github.svg)](https://agentmods.dev/rules/reillyjodonnell/react-debugger/01-diagnose-before-fixing)
Your own site
<a href="https://agentmods.dev/rules/reillyjodonnell/react-debugger/01-diagnose-before-fixing"><img src="https://agentmods.dev/badge/rules/reillyjodonnell/react-debugger/01-diagnose-before-fixing/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.

agentmods 80×15 button for 01-diagnose-before-fixing

Your own site · 80×15
<a href="https://agentmods.dev/rules/reillyjodonnell/react-debugger/01-diagnose-before-fixing"><img src="https://agentmods.dev/badge/rules/reillyjodonnell/react-debugger/01-diagnose-before-fixing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 140 This file is loaded in full into every session.
When invoked 140 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found 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 5.1 $0.00140 $0.00140
Opus 5.5 $0.00056 $0.00056
Sonnet 5.5 $0.00028 $0.00028
Haiku 4.5 $0.00014 $0.00014

Measured 1mo ago against content hash 1a8606f0dbb7, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

01-diagnose-before-fixing 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.

.cursor/rules/01-diagnose-before-fixing.mdc · 16 lines

What it actually says

When you are helping debug React bugs, follow this workflow:

  1. Diagnose before editing.
  2. Do not propose or change code before using the React Debugger tools:
    • tools/call subscribe → capture fid
    • tools/call nextEvents → wait for snapshot/commit
    • tools/call getProps or tools/call getHooksState using that fid
  3. Only after stating your diagnosis, backed by evidence, may you propose code changes.
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. 1mo ago First seen · 16 lines · 140 tokens per session scan A 1a8606f0dbb7

Subscribe to this mod's changes

01-diagnose-before-fixing is a cursor rule published in the GitHub repository reillyjodonnell/react-debugger (25 stars, last pushed 1y ago), licensed MIT. It adds 140 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 2026-08-30.