concurrency-anomaly-detector

concurrency-anomaly-detector is a skill for Claude Code from bookforge-ai/bookforge-skills. It costs 249 tokens per session (6,530 once invoked), scanned A, original, CC-BY-SA-4.0.

A checker for application code, SQL queries, and ORM code that looks for database concurrency anomalies—incorrect results that can occur when multiple operations run at the same time. It produces a report with affected locations, severity, and suggested fixes.

In plain words
What is it for?
Use it when auditing transaction code or investigating nondeterministic database bugs caused by simultaneous requests or jobs.
Why use it?
It helps identify race conditions and possible data corruption that may appear only under concurrent load and be difficult to reproduce manually.

Skill for Claude Code

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

Part of the designing-data-intensive-applications plugin — 14 skills shipped together

Good fit Use it when auditing transaction code or investigating nondeterministic database bugs caused by simultaneous requests or jobs.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/bookforge-ai/bookforge-skills/concurrency-anomaly-detector
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 bookforge-ai/bookforge-skills --skill concurrency-anomaly-detector
Clone the repo
git clone --depth 1 https://github.com/bookforge-ai/bookforge-skills

Made for: Claude Code.

Or install designing-data-intensive-applications, the plugin that ships this one along with the rest of its 14 skills.

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 concurrency-anomaly-detector

README.md
[![agentmods](https://agentmods.dev/badge/skills/bookforge-ai/bookforge-skills/concurrency-anomaly-detector/github.svg)](https://agentmods.dev/skills/bookforge-ai/bookforge-skills/concurrency-anomaly-detector)
Your own site
<a href="https://agentmods.dev/skills/bookforge-ai/bookforge-skills/concurrency-anomaly-detector"><img src="https://agentmods.dev/badge/skills/bookforge-ai/bookforge-skills/concurrency-anomaly-detector/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 concurrency-anomaly-detector

Your own site · 80×15
<a href="https://agentmods.dev/skills/bookforge-ai/bookforge-skills/concurrency-anomaly-detector"><img src="https://agentmods.dev/badge/skills/bookforge-ai/bookforge-skills/concurrency-anomaly-detector.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 249 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,530 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 $0.00249 $0.06530
Opus 5 $0.00125 $0.03265
Sonnet 5 $0.00050 $0.01306
Haiku 4.5 $0.00025 $0.00653

Measured 11d ago against content hash 0efe2027fe3a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

concurrency-anomaly-detector 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.

books/designing-data-intensive-applications/skills/concurrency-anomaly-detector/SKILL.md · 539 lines

The source is not reproduced here

Licensed CC-BY-SA-4.0

The repository is licensed CC-BY-SA-4.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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. 11d ago First seen · 539 lines · 249 tokens per session scan A 0efe2027fe3a

Subscribe to this mod's changes

concurrency-anomaly-detector is a skill published in the GitHub repository bookforge-ai/bookforge-skills (35 stars, last pushed 4mo ago), licensed CC-BY-SA-4.0. It adds 249 tokens to every session and 6,530 once invoked, about $0.0012 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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