competition-race-condition-state-drift

competition-race-condition-state-drift is a skill for Claude Code, Codex from 2233admin/reverse-skill-evolver. It costs 105 tokens per session (556 once invoked), scanned A, a copy of competition-race-condition-state-drift, MIT.

A CTF workflow for reproducing bugs caused by timing, concurrency, ordering, stale state, or missing locks. A race condition occurs when results depend on operations happening in a particular order.

In plain words
What is it for?
Use it to test concurrent requests, worker races, cache or session drift, counter errors, idempotency failures, lock gaps, and corrupted final state.
Why use it?
It isolates the shared state and exact read, check, write, queue, and commit sequence that causes inconsistent results.

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/2233admin/reverse-skill-evolver/competition-race-condition-state-drift
Any agent
npx skills add 2233admin/reverse-skill-evolver --skill competition-race-condition-state-drift
Clone the repo
git clone --depth 1 https://github.com/2233admin/reverse-skill-evolver

Made for: Claude Code, Codex.

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 competition-race-condition-state-drift

README.md
[![agentmods](https://agentmods.dev/badge/skills/2233admin/reverse-skill-evolver/competition-race-condition-state-drift.svg)](https://agentmods.dev/skills/2233admin/reverse-skill-evolver/competition-race-condition-state-drift)
Your own site
<a href="https://agentmods.dev/skills/2233admin/reverse-skill-evolver/competition-race-condition-state-drift"><img src="https://agentmods.dev/badge/skills/2233admin/reverse-skill-evolver/competition-race-condition-state-drift.svg" alt="Measured on agentmods" height="20"></a>
Per session 105 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 556 The whole file, excluding the scripts and references it only reads on demand.
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 5.1 $0.00105 $0.00556
Opus 5 $0.00053 $0.00278
Sonnet 5 $0.00021 $0.00111
Haiku 4.5 $0.00011 $0.00056

Measured 5d ago against content hash 94338b6e6354, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

competition-race-condition-state-drift 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 5d 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 competition-race-condition-state-drift — 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.

CTF-Sandbox-Orchestrator/competition-race-condition-state-drift/SKILL.md · 51 lines

How it starts

The opening of the file, as written. The whole thing — 51 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Competition Race Condition State Drift

Use this skill only as a downstream specialization after $ctf-sandbox-orchestrator is already active and has established sandbox assumptions, node ownership, and evidence priorities. If that has not happened yet, return to $ctf-sandbox-orchestrator first.

Use this skill when the decisive behavior depends on request timing, async ordering, lock gaps, or stale state.

Reply in Simplified Chinese unless the user explicitly requests English.

Quick Start

  1. Identify mutable state first: rows, cache keys, queue payloads, session fields, counters, or files.
  2. Reproduce with smallest concurrent sequence and fixed timing assumptions.
  3. Capture one baseline run and one racing run with only one variable changed.
  4. Track read, check, write, enqueue, and commit boundaries separately.
  5. Prove final state drift from a clean reset.

Workflow

1. Map Mutable Boundaries

  • Record transaction scope, lock behavior, retry logic, idempotency keys, cache invalidation, and queue handoff.
  • Note where read-check-write is split across requests, workers, or services.
  • Keep each boundary tied to exact timestamps or sequence numbers.

2. Reproduce Timing Window

  • Build deterministic concurrent inputs with controlled delay, duplicate requests, or reordered worker execution.
  • Compare accepted and rejected paths under identical payloads.
  • Record which condition flips when ordering changes.

3. Reduce To Decisive Race Chain

  • Compress to: request A and B ordering -> stale check or lock gap -> conflicting writes -> resulting capability or artifact.
  • State whether root cause is missing lock, weak idempotency, stale cache read, delayed async commit, or retry side effect.
  • If the path becomes queue-dominant, hand off to queue worker drift skill.

Read This Reference

  • Load references/race-condition-state-drift.md for race harness ideas, evidence blocks, and parity checks.

What To Preserve

  • Mutable keys, transaction boundaries, lock behavior, and idempotency markers
  • Timestamped or sequenced traces for baseline and race runs
  • One minimal replayable concurrent sequence proving drift

Read the full file on GitHub · 51 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 5d ago First seen · 51 lines · 105 tokens per session scan A 94338b6e6354

Subscribe to this mod's changes

competition-race-condition-state-drift is a skill published in the GitHub repository 2233admin/reverse-skill-evolver (13 stars, last pushed 25d ago), licensed MIT. It adds 105 tokens to every session and 556 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to competition-race-condition-state-drift, differing in 0 lines, and is treated as a copy.

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