read-the-trace

A method for diagnosing crashes by reading the complete stack trace, which shows the calls that led to an error. It focuses on the deepest frame belonging to your code and the incorrect value involved.

In plain words
What is it for?
Use it for exceptions and crashes, especially when the trace includes library code or a caused-by section. Reproduce the failure with the same input before changing the code.
Why use it?
The error label alone is too broad to identify the cause. Following the value back to where it became wrong leads to a more accurate fix.

Skill for Claude CodeCodex

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 skills/archive228/loopkit/read-the-trace
Any agent
npx skills add Archive228/loopkit --skill read-the-trace
Clone the repo
git clone --depth 1 https://github.com/Archive228/loopkit

Made for: Claude Code, Codex.

Per session 29 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 197 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00029 $0.00197
Opus 5 $0.00015 $0.00098
Sonnet 5 $0.00006 $0.00039
Haiku 4.5 $0.00003 $0.00020

Measured 2d ago against content hash a8cd91eb9486, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

read-the-trace 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.

skills/read-the-trace/SKILL.md · 13 lines

What it actually says

Read the Trace

LLMs love to see "TypeError" and generate a generic fix without reading the trace. Don't.

  • Find the deepest frame in YOUR code — not the library frame at the top. That's where the bad value entered.
  • Read the actual values: what was null/undefined/wrong-type, and where it came from.
  • Trace it one level up: why was that value bad? The root is usually 1-2 frames above the throw.
  • Reproduce with that exact input before fixing. A TypeError can mean a hundred things. The trace tells you which one — read all of it, including the "caused by".
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 · 13 lines · 29 tokens per session scan A a8cd91eb9486

Subscribe to this mod's changes

read-the-trace is a skill published in the GitHub repository Archive228/loopkit (753 stars, last pushed 1mo ago), licensed MIT. It adds 29 tokens to every session and 197 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 2026-08-30.

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