idempotency-key-check

idempotency-key-check is a skill for Claude Code from sina-heidariaan/cold-run. It costs 92 tokens per session (2,262 once invoked), scanned A, original, no licence file.

A check for making retried operations safe when they can create duplicates, such as charges, database inserts, messages, or publications. It identifies the idempotency key, which is a shared identifier that makes a repeat return the original result.

In plain words
What is it for?
Use it to review retry logic for operations that create records, send something, publish something, or charge money.
Why use it?
It helps prevent a second attempt from creating or accumulating the same result, and removes retries when no suitable key exists.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the cold-run plugin — 24 skills, 3 commands, 1 MCP server shipped together

Good fit Use it to review retry logic for operations that create records, send something, publish something, or charge money.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sina-heidariaan/cold-run/idempotency-key-check
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.

Any agent
npx skills add sina-heidariaan/cold-run --skill idempotency-key-check
Clone the repo
git clone --depth 1 https://github.com/sina-heidariaan/cold-run

Made for: Claude Code.

Or install cold-run, the plugin that ships this one along with the rest of its 24 skills, 3 commands, 1 MCP server.

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 idempotency-key-check

README.md
[![agentmods](https://agentmods.dev/badge/skills/sina-heidariaan/cold-run/idempotency-key-check/github.svg)](https://agentmods.dev/skills/sina-heidariaan/cold-run/idempotency-key-check)
Your own site
<a href="https://agentmods.dev/skills/sina-heidariaan/cold-run/idempotency-key-check"><img src="https://agentmods.dev/badge/skills/sina-heidariaan/cold-run/idempotency-key-check/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 idempotency-key-check

Your own site · 80×15
<a href="https://agentmods.dev/skills/sina-heidariaan/cold-run/idempotency-key-check"><img src="https://agentmods.dev/badge/skills/sina-heidariaan/cold-run/idempotency-key-check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 92 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,262 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00092 $0.02262
Opus 5 $0.00046 $0.01131
Sonnet 5 $0.00018 $0.00452
Haiku 4.5 $0.00009 $0.00226

Measured 11d ago against content hash ac5c1c765eaf, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

idempotency-key-check 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 11d 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/idempotency-key-check/SKILL.md · 157 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

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. 11d ago First seen · 157 lines · 92 tokens per session scan A ac5c1c765eaf

Subscribe to this mod's changes

idempotency-key-check is a skill published in the GitHub repository sina-heidariaan/cold-run (0 stars, last pushed 20d ago), with no licence file. It adds 92 tokens to every session and 2,262 once invoked, about $0.0005 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.

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