ddd-cross-aggregate-constraints

ddd-cross-aggregate-constraints is a skill for Claude Code, Codex from amadeus-dlc/amadeus. It costs 81 tokens per session (371 once invoked), scanned A, original, Apache-2.0.

A guide for deciding how one business object should respond when a rule depends on another business object’s state. An aggregate is a group of related data changed as one unit.

In plain words
What is it for?
Use it when validating across aggregates, designing CQRS or event-sourced systems, deciding whether to merge boundaries, or choosing reservations, events, policies, or compensating actions.
Why use it?
It helps distinguish rules that must be enforced immediately from policies that can tolerate a delay, avoiding stale checks and unsuitable multi-step workflows.

Skill for Claude CodeCodex

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

Good fit Use it when validating across aggregates, designing CQRS or event-sourced systems, deciding whether to merge boundaries, or choosing reservations, events, policies, or compensating actions.

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Install with agentmods
npx agentmods add skills/amadeus-dlc/amadeus/ddd-cross-aggregate-constraints
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 amadeus-dlc/amadeus --skill ddd-cross-aggregate-constraints
Clone the repo
git clone --depth 1 https://github.com/amadeus-dlc/amadeus

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 ddd-cross-aggregate-constraints

README.md
[![agentmods](https://agentmods.dev/badge/skills/amadeus-dlc/amadeus/ddd-cross-aggregate-constraints/github.svg)](https://agentmods.dev/skills/amadeus-dlc/amadeus/ddd-cross-aggregate-constraints)
Your own site
<a href="https://agentmods.dev/skills/amadeus-dlc/amadeus/ddd-cross-aggregate-constraints"><img src="https://agentmods.dev/badge/skills/amadeus-dlc/amadeus/ddd-cross-aggregate-constraints/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 ddd-cross-aggregate-constraints

Your own site · 80×15
<a href="https://agentmods.dev/skills/amadeus-dlc/amadeus/ddd-cross-aggregate-constraints"><img src="https://agentmods.dev/badge/skills/amadeus-dlc/amadeus/ddd-cross-aggregate-constraints.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 81 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 371 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 $0.00081 $0.00371
Opus 5 $0.00041 $0.00186
Sonnet 5 $0.00016 $0.00074
Haiku 4.5 $0.00008 $0.00037

Measured 10d ago against content hash 6d9be79ad1ad, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

ddd-cross-aggregate-constraints 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.

amadeus/spaces/default/knowledge/amadeus-shared/software-design/ddd-cross-aggregate-constraints/SKILL.md · 40 lines

What it actually says

DDD Cross-Aggregate Constraints

A cross-aggregate constraint is usually a requirements question before it is a technical question.

Workflow

  1. Restate the rule in business language and ask whether it must be immediately true.

  2. If it is a true invariant, consider merging the aggregate boundary or changing the command owner.

  3. If it is a policy, use events, reservations, or compensating actions; use a saga only for multi-step orchestration and compensation, not for synchronous existence checks.

  4. In CQRS/ES, avoid command decisions based on stale read models unless the business accepts that staleness.

  5. Document the inconsistency window and repair mechanism.

Decision Options

  • Same aggregate: use when the rule is a true invariant.

  • Reservation aggregate: use when scarce resources need temporary holds.

  • Policy or saga: use when the reaction can be eventual; reject saga for rules that must block the first command synchronously.

  • Read-model check: use only when stale decisions are acceptable.

Detailed Reference

For non-trivial implementation, review, or refactoring work, read references/details.md before giving final guidance. It contains the detailed rules, examples, smells, and migration notes that do not belong in the short invocation body.

Output

Return the business interpretation, chosen consistency model, rejected options, and exact failure/retry behavior.

Files

What ships with it

1 file 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. 10d ago First seen · 40 lines · 81 tokens per session scan A 6d9be79ad1ad

Subscribe to this mod's changes

ddd-cross-aggregate-constraints is a skill published in the GitHub repository amadeus-dlc/amadeus (8 stars, last pushed 20d ago), licensed Apache-2.0. It adds 81 tokens to every session and 371 once invoked, about $0.0004 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 2026-08-31.

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