root-cause-tracing

root-cause-tracing is a cursor rule for coding agents from nlewis84/ai-rules. It costs 12 tokens per session (1,359 once invoked), scanned A, original, GPL-3.0.

A debugging rule for tracing a failure backward through the call stack, which is the chain of functions that led to an error. It focuses on finding the original trigger rather than only the visible symptom.

In plain words
What is it for?
Use it when investigating bugs that pass through several functions or components. The input provides the rule's purpose but no further procedure.
Why use it?
It helps avoid applying a fix at the first place an error appears when the real cause happened earlier.

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/nlewis84/ai-rules/root-cause-tracing
Clone the repo
git clone --depth 1 https://github.com/nlewis84/ai-rules

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 root-cause-tracing

README.md
[![agentmods](https://agentmods.dev/badge/rules/nlewis84/ai-rules/root-cause-tracing.svg)](https://agentmods.dev/rules/nlewis84/ai-rules/root-cause-tracing)
Your own site
<a href="https://agentmods.dev/rules/nlewis84/ai-rules/root-cause-tracing"><img src="https://agentmods.dev/badge/rules/nlewis84/ai-rules/root-cause-tracing.svg" alt="Measured on agentmods" height="20"></a>
Per session 12 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,359 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00012 $0.01359
Opus 5 $0.00006 $0.00679
Sonnet 5 $0.00002 $0.00272
Haiku 4.5 $0.00001 $0.00136

Measured 4d ago against content hash a6389e0c1191, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

root-cause-tracing 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 4d 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.

root-cause-tracing.mdc · 175 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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. 4d ago First seen · 175 lines · 12 tokens per session scan A a6389e0c1191

Subscribe to this mod's changes

root-cause-tracing is a cursor rule published in the GitHub repository nlewis84/ai-rules (3 stars, last pushed 10mo ago), licensed GPL-3.0. It adds 12 tokens to every session and 1,359 once invoked, about $0.0001 per session on Opus 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 2026-08-31.