What is Data Flow & State Ownership?

A review checklist for designs that examines where data comes from, which system owns it, and how updates cross system boundaries. It also checks consistency, tracking, and recovery assumptions.

Use it when reviewing flow diagrams, sequence diagrams, or data-flow designs. It helps document the source of truth, write direction, duplicate-event handling, conflicts, audit logs, and replay or recovery plans.

Unclear ownership or duplicated writes can make data disagree and make failures difficult to recover from. The checklist surfaces those gaps before implementation.

Data Flow & State Ownership — Skill for Claude Code by s977043

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 s977043/river-review --skill data-flow-state-ownership

Clone the repo

git clone --depth 1 https://github.com/s977043/river-review

Made for: Claude Code.

Or install river-review, the plugin that ships this one along with the rest of its 139 skills, 18 commands, 5 agents, 3 hooks.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/s977043/river-review/data-flow-state-ownership/github.svg)](https://agentmods.dev/skills/s977043/river-review/data-flow-state-ownership)

Your own site

<a href="https://agentmods.dev/skills/s977043/river-review/data-flow-state-ownership"><img src="https://agentmods.dev/badge/skills/s977043/river-review/data-flow-state-ownership/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/s977043/river-review/data-flow-state-ownership"><img src="https://agentmods.dev/badge/skills/s977043/river-review/data-flow-state-ownership.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 29 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,351 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.

Model	Per session	Once invoked
Fable 5.1	$0.00029	$0.01351
Opus 5.5	$0.00012	$0.00540
Sonnet 5.5	$0.00006	$0.00270
Haiku 4.5	$0.00003	$0.00135

Measured 2mo ago against content hash fc9912d52df4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

Data Flow & State Ownership 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 2mo 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.

plugin-dist/river-review/skills/upstream/data-flow-state-ownership/SKILL.md · 101 lines

What it actually says

Pattern declaration

Primary pattern: Reviewer Secondary patterns: Inversion Why: データフローと状態所有の曖昧さをチェックリスト型で評価し、整合性崩れや二重書き込みを事前に検出する

Goal / 目的

設計の差分から、データフロー/状態所有の曖昧さによる整合性崩れ・二重書き込み・障害時の復旧困難を減らす。

Non-goals / 扱わないこと

分散システムの一般論を長々と語らない（差分に紐づく具体的な曖昧さに限定）。
実装レベルの最適化（キュー設定や DB チューニングなど）。

Pre-execution Gate / 実行前ゲート

このスキルは以下の条件がすべて満たされない限りNO_REVIEWを返す。

差分に設計ドキュメント（フロー図/シーケンス図/データフロー設計書）の変更がある
差分にデータフロー・状態所有・境界横断の書き込みに関わる記述の追加または変更がある
inputContextにdiffが含まれている

ゲート不成立時の出力: NO_REVIEW: data-flow-state-ownership — データフロー・状態所有に関わる変更が検出されない

False-positive guards / 抑制条件

PoC/運用対象外と明記されている場合は、強度を落として “確認事項” に倒す。

Rule / ルール

先頭に要約を 1 行出す（追加/変更されたデータフローと所有の要点）。
指摘は最大 8 件まで。整合性・二重書き込み・競合・障害復旧に直結するものを優先。
可能なら “追記テンプレ” を付ける（文書に貼れる形）。

Checklist / 観点チェックリスト

状態所有（Source of Truth）
- 主要エンティティ/状態の SoT（誰が唯一の真実か）が明示されているか。
- 同じ状態を複数の境界で更新しない設計になっているか（必要なら理由とガードがあるか）。
境界横断の書き込み
- どの境界からどの境界へ “書く” のか、同期/非同期、順序保証の前提があるか。
- 二重実行/重複配信への対策（冪等性キー、upsert、dedupe）が設計にあるか。
整合性と競合
- 強整合/最終整合の選択と、ユーザー体験への影響が説明されているか。
- 競合（同時更新）の扱い（楽観ロック、解決戦略、再試行方針）があるか。
監査と追跡
- 重要イベントの監査ログ、相関ID など、追跡可能性の前提があるか。
リカバリ
- 再処理/リプレイ、DLQ、補償処理などの前提があるか（必要な場合）。

Output / 出力フォーマット

すべて日本語。<file>:<line>: <message> 形式で出力する。

先頭に要約を 1 行: (summary):1: <データフロー/所有/整合性の要点>
以降は指摘（最大 8 件）:
- <message> に [severity=critical|major|minor|info] を含める。
- 可能なら “追記テンプレ” を 1 行付ける。

追記テンプレ例:

SoT: <エンティティ>=<所有者境界> / 更新元: <境界> / 反映: <同期/非同期> / 冪等性: <キー>
整合性: <強/最終> / 競合: <方針> / 失敗時: <再試行/補償/再処理>

評価指標（Evaluation）

合格基準: 差分に紐づく所有/整合性の抜けを優先度付きで指摘し、追記案がある。
不合格基準: 根拠のない断定、差分と無関係な一般論、指摘過多。

人間に返す条件（Human Handoff）

整合性モデルの選択がプロダクト要件に直結する場合は人間（設計/PM）へ返す。

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.

2mo ago First seen · 101 lines · 29 tokens per session scan A fc9912d52df4

Subscribe to this mod's changes

Data Flow & State Ownership is a skill published in the GitHub repository s977043/river-review (7 stars, last pushed yesterday), licensed MIT. It adds 29 tokens to every session and 1,351 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-09-03.

Claude Code Code review Debugging Planning adversarial-review ai-code-review architecture claude-code-plugin codex dataflow ownership state upstream

Data Flow & State Ownership next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
Data Flow & State Ownerships977043/river-review	Skill	7	yesterday	MIT	A	29	Claude Code
review-allncoevoet/claude-review-all	Skill	45	4d ago	MIT	A	74	Claude Code
logic-reviewhyhmrright/logic-lens	Skill	25	7d ago	MIT	A	161	Claude Code
logic-fix-allhyhmrright/logic-lens	Skill	25	7d ago	MIT	A	211	Claude Code
logic-healthhyhmrright/logic-lens	Skill	25	7d ago	MIT	A	180	Claude Code
logic-explainhyhmrright/logic-lens	Skill	25	7d ago	MIT	A	171	Claude Code
logic-locatehyhmrright/logic-lens	Skill	25	7d ago	MIT	A	177	Claude Code