race-condition

race-condition is a skill for Claude Code, Codex from sanjaysaini1952/BugBounty-Arsenal. It costs 0 tokens per session (407 once invoked), scanned A, original, MIT.

A checklist for finding race conditions, which happen when simultaneous requests interfere with each other and produce an invalid result. It tests concurrent actions such as transfers, coupon use, logins, purchases, and account creation.

In plain words
What is it for?
Testing duplicate transfers, coupon redemptions, OTP attempts, purchases beyond stock, token generation, duplicate accounts, and concurrent workflow steps.
Why use it?
It can expose cases where an application checks a rule once but allows multiple requests to pass before the state is updated.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Testing duplicate transfers, coupon redemptions, OTP attempts, purchases beyond stock, token generation, duplicate accounts, and concurrent workflow steps.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sanjaysaini1952/bugbounty-arsenal/race-condition
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 sanjaysaini1952/BugBounty-Arsenal --skill race-condition
Clone the repo
git clone --depth 1 https://github.com/sanjaysaini1952/BugBounty-Arsenal

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 race-condition

README.md
[![agentmods](https://agentmods.dev/badge/skills/sanjaysaini1952/bugbounty-arsenal/race-condition/github.svg)](https://agentmods.dev/skills/sanjaysaini1952/bugbounty-arsenal/race-condition)
Your own site
<a href="https://agentmods.dev/skills/sanjaysaini1952/bugbounty-arsenal/race-condition"><img src="https://agentmods.dev/badge/skills/sanjaysaini1952/bugbounty-arsenal/race-condition/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 race-condition

Your own site · 80×15
<a href="https://agentmods.dev/skills/sanjaysaini1952/bugbounty-arsenal/race-condition"><img src="https://agentmods.dev/badge/skills/sanjaysaini1952/bugbounty-arsenal/race-condition.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 407 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 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 $0.00000 $0.00407
Opus 5 $0.00000 $0.00204
Sonnet 5 $0.00000 $0.00081
Haiku 4.5 $0.00000 $0.00041

Measured 12d ago against content hash 0b48041350bf, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

race-condition 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 12d 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/hunting/race-condition/SKILL.md · 47 lines

What it actually says

Race Condition Hunting Skill — 8 Test Cases

Load when: race condition, TOCTOU, time-of-check time-of-use, concurrent request.

140. Race condition in fund transfer (medium)

Send 10 simultaneous transfer requests (same amount, same account). Check if balance allows multiple transfers beyond available funds.

141. Race in coupon redemption (medium)

Send simultaneous requests to redeem same coupon code. Check if used once or multiple times.

142. Race in OTP verification (medium)

Send parallel OTP verification requests. Check if multiple attempts bypass rate limiting.

143. Race in inventory (medium)

Send concurrent add-to-cart or purchase requests for limited stock. Check overselling.

144. Race in token generation (medium)

Request password reset or API tokens simultaneously. Check if multiple valid tokens are generated (only last should be valid).

145. Race in account creation (medium)

Create same user simultaneously. Check if duplicate accounts or inconsistent state results.

146. Race in multi-step process (hard)

In workflows (checkout, onboarding), send intermediate steps out of order or concurrently. Check state inconsistencies.

147. Race in file operations (hard)

Upload and delete same file simultaneously. Check for TOCTOU vulnerability (file exists check vs. actual operation).


Testing Methodology

  1. Identify state-changing endpoints
  2. Use multiple threads (Turbo Intruder, Burp Group Send, custom script)
  3. Send 10-50 concurrent requests
  4. Analyze response for anomalies
  5. Check state after race (balance, count, state)
  6. Verify reproducibility
  7. Document with timestamps and evidence

Race Detection Heuristics

Signal Description
Balance anomaly More transfers than balance allows
Duplicate resources Two users with same username
Count mismatch Counter says 5, actual items 7
State corruption Mixed/invalid state in database
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. 12d ago First seen · 47 lines · 0 tokens per session scan A 0b48041350bf

Subscribe to this mod's changes

race-condition is a skill published in the GitHub repository sanjaysaini1952/BugBounty-Arsenal (2 stars, last pushed 1mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 407 tokens. 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.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

local-ai-agents

Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…

microsoft/ai-agents-for-beginners · 200 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

chat-pet-sprite-creation

Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.

microsoft/vscode · 53 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

insight-error-page

Write or audit an insight-kind error page for the Next.js dev overlay. Use when creating a new errors/ .mdx page, auditing an existing one, or checking that a page matches the framework fix cards. Covers page structure, title alignment, FixCard cards with Copy prompt button, code snippets, terminology verification…

vercel/next.js · 83 tokens