cqrs-tradeoffs

cqrs-tradeoffs is a skill for Claude Code, Codex from j5ik2o/okite-ai. It costs 260 tokens per session (2,403 once invoked), scanned A, a copy of cqrs-to-event-sourcing, MIT.

A guide for deciding whether CQRS fits a system. CQRS separates the parts of an application that change data from the parts that read it, and the guide explains its trade-offs around consistency, availability, and scaling.

In plain words
What is it for?
Use it to assess CQRS, with or without event sourcing, and to plan consistency, availability, and scaling choices across read and write models.
Why use it?
It helps compare design options before introducing separate read and write models, especially in distributed systems where network failures force trade-offs.

Skill for Claude CodeCodex

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

Good fit Use it to assess CQRS, with or without event sourcing, and to plan consistency, availability, and scaling choices across read and write models.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/j5ik2o/okite-ai/cqrs-tradeoffs
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 j5ik2o/okite-ai --skill cqrs-tradeoffs
Clone the repo
git clone --depth 1 https://github.com/j5ik2o/okite-ai

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 cqrs-tradeoffs

README.md
[![agentmods](https://agentmods.dev/badge/skills/j5ik2o/okite-ai/cqrs-tradeoffs/github.svg)](https://agentmods.dev/skills/j5ik2o/okite-ai/cqrs-tradeoffs)
Your own site
<a href="https://agentmods.dev/skills/j5ik2o/okite-ai/cqrs-tradeoffs"><img src="https://agentmods.dev/badge/skills/j5ik2o/okite-ai/cqrs-tradeoffs/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 cqrs-tradeoffs

Your own site · 80×15
<a href="https://agentmods.dev/skills/j5ik2o/okite-ai/cqrs-tradeoffs"><img src="https://agentmods.dev/badge/skills/j5ik2o/okite-ai/cqrs-tradeoffs.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 260 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,403 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 86% 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 $0.00260 $0.02403
Opus 5 $0.00130 $0.01202
Sonnet 5 $0.00052 $0.00481
Haiku 4.5 $0.00026 $0.00240

Measured 10d ago against content hash e580618be5e5, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

cqrs-tradeoffs 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 10d 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

86% identical to cqrs-to-event-sourcing — 280 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.

skills/cqrs-tradeoffs/SKILL.md · 171 lines

How it starts

The opening of the file, as written. The whole thing — 171 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CQRSトレードオフガイド

CQRSにおける一貫性・可用性・スケーラビリティのトレードオフを分析し、設計判断を支援する。

CAP定理に基づく評価軸

CQRSが一貫性と可用性を重要な評価軸として採用する理由は、CAP定理に基づいている。

分散システムでは、ネットワークの分断や障害が発生した場合、一貫性と可用性の間でトレードオフが生じることが避けられない。CQRSはこのトレードオフを巧みに活用する。

モデル 重視する特性 理由
書き込みモデル 一貫性 現在の状態に基づく意思決定・計算を行うため
読み込みモデル 可用性 最新の状態でなくても十分な場合が多いため

この分離により、一貫性と可用性を同時に追求するのではなく、各モデルで最適な戦略を選択できる。

CQRSの2つの形態

シンプルなCQRS(イベントソーシングなし)

  • 非CQRSベースのシステムと同様の一貫性を保証
  • 読み書きモデルの論理的な分離
  • 既存のRDBMS上でも実装可能

CQRS + イベントソーシング(CQRS/ES)

  • 読み込みモデルと書き込みモデルで一貫性レベルを独立して制御
  • 書き込みモデル: 強い一貫性
  • 読み込みモデル: 結果整合性
  • システムの柔軟性が大幅に向上

3つの評価軸

1. 一貫性への影響

書き込みモデル: システムの現在の状態に基づいて意思決定や計算を行うため、強い一貫性が求められる。

読み込みモデル: 最新の状態ではなくても十分な場合が多く、結果整合性が適用される。これにより、パフォーマンスと応答速度の向上が期待できる。

形態 書き込みモデルの一貫性 読み込みモデルの一貫性
シンプルなCQRS 従来と同等 従来と同等
CQRS/ES 強い一貫性 結果整合性

2. 可用性への影響

CQRS/ESでは、書き込みモデルが強い一貫性を必要とする一方、読み込みモデルの結果整合性により高い可用性を実現できる。

障害時の振る舞い:

  • 書き込みを一時停止しても、読み込み操作は継続可能
  • システムの全面的なダウンを回避できる
  • キャッシュやレプリケーション機能により、障害発生時でもサービスの可用性を維持

3. スケーラビリティへの影響

読み込みモデルと書き込みモデルを分離して独立にスケールさせることができる。

読み込みモデル:

  • 多くのアプリケーションが読み込み重視
  • キャッシュやレプリケーションを活用して高いスケーラビリティを実現
  • 異なるマイクロサービスが異なるプロジェクションをホストし、特定のクエリに特化

書き込みモデル:

  • シャーディングや他の分散技術を活用
  • 書き込み負荷に応じた独立スケーリング

RDB構成との本質的類似性

CQRSのトレードオフは、RDBの1台ライター / N台リードレプリカ構成と本質的に同じである。

観点 CQRS/ES RDB 1W/NR構成
書き込み 強い一貫性 マスターへの書き込み
読み込み 結果整合性 レプリカからの読み込み
障害時 読み込み継続可 レプリカで読み込み継続可
スケーリング 読み書き独立 レプリカ追加で読み込みスケール

どちらもCAP定理に基づくトレードオフが生じるため、同じ考え方が適用される。この類似性を理解することで、CQRSの導入ハードルを下げることができる。

設計判断フロー

CQRSの採用判断

1. 読み込みと書き込みの負荷特性が異なるか?
   → No: シンプルなCRUDで十分な可能性
   → Yes: 次へ

2. 読み込みと書き込みで異なるモデルが有利か?
   → No: 単一モデルで対応可能
   → Yes: シンプルなCQRSを検討 → 次へ

3. 読み込みモデルで結果整合性を許容できるか?
   → No: シンプルなCQRS(同一DB)を検討
   → Yes: CQRS/ESを検討 → 次へ

4. 高い可用性・スケーラビリティが要求されるか?
   → No: シンプルなCQRSで十分
   → Yes: CQRS/ES + 読み書きモデルの物理分離を検討

Read the full file on GitHub · 171 lines

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. 10d ago First seen · 171 lines · 260 tokens per session scan A e580618be5e5

Subscribe to this mod's changes

cqrs-tradeoffs is a skill published in the GitHub repository j5ik2o/okite-ai (81 stars, last pushed 4mo ago), licensed MIT. It adds 260 tokens to every session and 2,403 once invoked, about $0.0013 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to cqrs-to-event-sourcing, differing in 280 lines, and is treated as a copy.

Related

Other skills, from other repositories

mem0-oss-to-platform

Plan and then execute a migration of a project from the mem0 open-source / self-hosted SDK (the local Memory class) to the mem0 Platform / hosted / managed SDK (the MemoryClient class). Use this whenever a developer wants to move, switch, or migrate their mem0 usage off OSS/self-hosted to the hosted API — e.g.…

mem0ai/mem0 · 273 tokens

agui-dotnet-protobuf

Use the protobuf wire transport (instead of the default Server-Sent Events) for an AG-UI connection with the AG-UI .NET SDK — a compact binary event stream negotiated via the Accept header. USE FOR: making an AGUIChatClient prefer protobuf by wiring an AGUIEventStreamHandler with ProtobufEventStreamFormatter (then…

ag-ui-protocol/ag-ui · 162 tokens

azure-mgmt-botservice-dotnet

Azure Resource Manager SDK for Bot Service in .NET. Management plane operations for creating and managing Azure Bot resources, channels (Teams, DirectLine, Slack), and connection settings. Triggers: "Bot Service", "BotResource", "Azure Bot", "DirectLine channel", "Teams channel", "bot management .NET", "create bot".

microsoft/skills · 78 tokens

fastapi-router-py

Create FastAPI routers with CRUD operations, authentication dependencies, and proper response models. Use when building REST API endpoints, creating new routes, implementing CRUD operations, or adding authenticated endpoints in FastAPI applications.

microsoft/skills · 46 tokens

aws-sdk-java-v2-core

Provides AWS SDK for Java 2.x client configuration, credential resolution, HTTP client tuning, timeout, retry, and testing patterns. Use when creating or hardening AWS service clients, wiring Spring Boot beans, debugging auth or region issues, or choosing sync vs async SDK usage.

giuseppe-trisciuoglio/developer-kit · 62 tokens

migrate-segw-to-rap

Reverse-engineer a SEGW-built OData V2 service (MPC/DPC/MPCEXT/DPCEXT) into a modern RAP V4 service — tables, CDS views (interface + projection), behavior definitions, draft entities, service definition + binding. Use when asked to "migrate this SEGW service to RAP", "convert OData V2 to V4 RAP", "modernize this…

arc-mcp/arc-1 · 106 tokens